diff mbox series

[bpf-next,v2,18/20] selftests/bpf: Use AF_INET for TX in xdp_metadata

Message ID 20230703181226.19380-19-larysa.zaremba@intel.com (mailing list archive)
State Changes Requested
Delegated to: BPF
Headers show
Series XDP metadata via kfuncs for ice | expand

Checks

Context Check Description
bpf/vmtest-bpf-next-PR success PR summary
bpf/vmtest-bpf-next-VM_Test-1 success Logs for ${{ matrix.test }} on ${{ matrix.arch }} with ${{ matrix.toolchain_full }}
bpf/vmtest-bpf-next-VM_Test-2 success Logs for ShellCheck
bpf/vmtest-bpf-next-VM_Test-3 success Logs for build for aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-4 success Logs for build for s390x with gcc
bpf/vmtest-bpf-next-VM_Test-5 success Logs for build for x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-6 fail Logs for build for x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-7 success Logs for set-matrix
bpf/vmtest-bpf-next-VM_Test-8 success Logs for veristat
netdev/series_format fail Series longer than 15 patches (and no cover letter)
netdev/tree_selection success Clearly marked for bpf-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 8 this patch: 8
netdev/cc_maintainers warning 5 maintainers not CCed: hawk@kernel.org shuah@kernel.org mykolal@fb.com davem@davemloft.net linux-kselftest@vger.kernel.org
netdev/build_clang fail Errors and warnings before: 18 this patch: 18
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 8 this patch: 8
netdev/checkpatch warning WARNING: line length of 81 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 1 this patch: 1
netdev/source_inline success Was 0 now: 0

Commit Message

Larysa Zaremba July 3, 2023, 6:12 p.m. UTC
The easiest way to simulate stripped VLAN tag in veth is to send a packet
from VLAN interface, attached to veth. Unfortunately, this approach is
incompatible with AF_XDP on TX side, because VLAN interfaces do not have
such feature.

Replace AF_XDP packet generation with sending the same datagram via
AF_INET socket.

This does not change the packet contents or hints values with one notable
exception: rx_hash_type, which previously was expected to be 0, now is
expected be at least XDP_RSS_TYPE_L4.

Also, usage of AF_INET requires a little more complicated namespace setup,
therefore open_netns() helper function is divided into smaller reusable
pieces.

Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
---
 tools/testing/selftests/bpf/network_helpers.c |  37 +++-
 tools/testing/selftests/bpf/network_helpers.h |   3 +
 .../selftests/bpf/prog_tests/xdp_metadata.c   | 175 +++++++-----------
 3 files changed, 98 insertions(+), 117 deletions(-)

Comments

Stanislav Fomichev July 5, 2023, 5:39 p.m. UTC | #1
On 07/03, Larysa Zaremba wrote:
> The easiest way to simulate stripped VLAN tag in veth is to send a packet
> from VLAN interface, attached to veth. Unfortunately, this approach is
> incompatible with AF_XDP on TX side, because VLAN interfaces do not have
> such feature.
> 
> Replace AF_XDP packet generation with sending the same datagram via
> AF_INET socket.
> 
> This does not change the packet contents or hints values with one notable
> exception: rx_hash_type, which previously was expected to be 0, now is
> expected be at least XDP_RSS_TYPE_L4.
> 
> Also, usage of AF_INET requires a little more complicated namespace setup,
> therefore open_netns() helper function is divided into smaller reusable
> pieces.

Ack, it's probably OK for now, but, FYI, I'm trying to extend this part
with TX metadata:
https://lore.kernel.org/bpf/20230621170244.1283336-10-sdf@google.com/

So probably long-term I'll switch it back to AF_XDP but will add
support for requesting vlan TX "offload" from the veth.
 
> Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
> ---
>  tools/testing/selftests/bpf/network_helpers.c |  37 +++-
>  tools/testing/selftests/bpf/network_helpers.h |   3 +
>  .../selftests/bpf/prog_tests/xdp_metadata.c   | 175 +++++++-----------
>  3 files changed, 98 insertions(+), 117 deletions(-)
> 
> diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c
> index a105c0cd008a..19463230ece5 100644
> --- a/tools/testing/selftests/bpf/network_helpers.c
> +++ b/tools/testing/selftests/bpf/network_helpers.c
> @@ -386,28 +386,51 @@ char *ping_command(int family)
>  	return "ping";
>  }
>  
> +int get_cur_netns(void)
> +{
> +	int nsfd;
> +
> +	nsfd = open("/proc/self/ns/net", O_RDONLY);
> +	ASSERT_GE(nsfd, 0, "open /proc/self/ns/net");
> +	return nsfd;
> +}
> +
> +int get_netns(const char *name)
> +{
> +	char nspath[PATH_MAX];
> +	int nsfd;
> +
> +	snprintf(nspath, sizeof(nspath), "%s/%s", "/var/run/netns", name);
> +	nsfd = open(nspath, O_RDONLY | O_CLOEXEC);
> +	ASSERT_GE(nsfd, 0, "open /proc/self/ns/net");
> +	return nsfd;
> +}
> +
> +int set_netns(int netns_fd)
> +{
> +	return setns(netns_fd, CLONE_NEWNET);
> +}

We have open_netns/close_netns in network_helpers.h that provide similar
functionality, let's use them instead?

> +
>  struct nstoken {
>  	int orig_netns_fd;
>  };
>  
>  struct nstoken *open_netns(const char *name)
>  {
> +	struct nstoken *token;
>  	int nsfd;
> -	char nspath[PATH_MAX];
>  	int err;
> -	struct nstoken *token;
>  
>  	token = calloc(1, sizeof(struct nstoken));
>  	if (!ASSERT_OK_PTR(token, "malloc token"))
>  		return NULL;
>  
> -	token->orig_netns_fd = open("/proc/self/ns/net", O_RDONLY);
> -	if (!ASSERT_GE(token->orig_netns_fd, 0, "open /proc/self/ns/net"))
> +	token->orig_netns_fd = get_cur_netns();
> +	if (token->orig_netns_fd < 0)
>  		goto fail;
>  
> -	snprintf(nspath, sizeof(nspath), "%s/%s", "/var/run/netns", name);
> -	nsfd = open(nspath, O_RDONLY | O_CLOEXEC);
> -	if (!ASSERT_GE(nsfd, 0, "open netns fd"))
> +	nsfd = get_netns(name);
> +	if (nsfd < 0)
>  		goto fail;
>  
>  	err = setns(nsfd, CLONE_NEWNET);
> diff --git a/tools/testing/selftests/bpf/network_helpers.h b/tools/testing/selftests/bpf/network_helpers.h
> index 694185644da6..b18b9619595c 100644
> --- a/tools/testing/selftests/bpf/network_helpers.h
> +++ b/tools/testing/selftests/bpf/network_helpers.h
> @@ -58,6 +58,8 @@ int make_sockaddr(int family, const char *addr_str, __u16 port,
>  char *ping_command(int family);
>  int get_socket_local_port(int sock_fd);
>  
> +int get_cur_netns(void);
> +int get_netns(const char *name);
>  struct nstoken;
>  /**
>   * open_netns() - Switch to specified network namespace by name.
> @@ -67,4 +69,5 @@ struct nstoken;
>   */
>  struct nstoken *open_netns(const char *name);
>  void close_netns(struct nstoken *token);
> +int set_netns(int netns_fd);
>  #endif
> diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
> index 626c461fa34d..53b32a641e8e 100644
> --- a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
> +++ b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
> @@ -20,7 +20,7 @@
>  
>  #define UDP_PAYLOAD_BYTES 4
>  
> -#define AF_XDP_SOURCE_PORT 1234
> +#define UDP_SOURCE_PORT 1234
>  #define AF_XDP_CONSUMER_PORT 8080
>  
>  #define UMEM_NUM 16
> @@ -33,6 +33,12 @@
>  #define RX_ADDR "10.0.0.2"
>  #define PREFIX_LEN "8"
>  #define FAMILY AF_INET
> +#define TX_NETNS_NAME "xdp_metadata_tx"
> +#define RX_NETNS_NAME "xdp_metadata_rx"
> +#define TX_MAC "00:00:00:00:00:01"
> +#define RX_MAC "00:00:00:00:00:02"
> +
> +#define XDP_RSS_TYPE_L4 BIT(3)
>  
>  struct xsk {
>  	void *umem_area;
> @@ -119,90 +125,28 @@ static void close_xsk(struct xsk *xsk)
>  	munmap(xsk->umem_area, UMEM_SIZE);
>  }
>  
> -static void ip_csum(struct iphdr *iph)
> +static int generate_packet_udp(void)
>  {
> -	__u32 sum = 0;
> -	__u16 *p;
> -	int i;
> -
> -	iph->check = 0;
> -	p = (void *)iph;
> -	for (i = 0; i < sizeof(*iph) / sizeof(*p); i++)
> -		sum += p[i];
> -
> -	while (sum >> 16)
> -		sum = (sum & 0xffff) + (sum >> 16);
> -
> -	iph->check = ~sum;
> -}
> -
> -static int generate_packet(struct xsk *xsk, __u16 dst_port)
> -{
> -	struct xdp_desc *tx_desc;
> -	struct udphdr *udph;
> -	struct ethhdr *eth;
> -	struct iphdr *iph;
> -	void *data;
> -	__u32 idx;
> -	int ret;
> -
> -	ret = xsk_ring_prod__reserve(&xsk->tx, 1, &idx);
> -	if (!ASSERT_EQ(ret, 1, "xsk_ring_prod__reserve"))
> -		return -1;
> -
> -	tx_desc = xsk_ring_prod__tx_desc(&xsk->tx, idx);
> -	tx_desc->addr = idx % (UMEM_NUM / 2) * UMEM_FRAME_SIZE;
> -	printf("%p: tx_desc[%u]->addr=%llx\n", xsk, idx, tx_desc->addr);
> -	data = xsk_umem__get_data(xsk->umem_area, tx_desc->addr);
> -
> -	eth = data;
> -	iph = (void *)(eth + 1);
> -	udph = (void *)(iph + 1);
> -
> -	memcpy(eth->h_dest, "\x00\x00\x00\x00\x00\x02", ETH_ALEN);
> -	memcpy(eth->h_source, "\x00\x00\x00\x00\x00\x01", ETH_ALEN);
> -	eth->h_proto = htons(ETH_P_IP);
> -
> -	iph->version = 0x4;
> -	iph->ihl = 0x5;
> -	iph->tos = 0x9;
> -	iph->tot_len = htons(sizeof(*iph) + sizeof(*udph) + UDP_PAYLOAD_BYTES);
> -	iph->id = 0;
> -	iph->frag_off = 0;
> -	iph->ttl = 0;
> -	iph->protocol = IPPROTO_UDP;
> -	ASSERT_EQ(inet_pton(FAMILY, TX_ADDR, &iph->saddr), 1, "inet_pton(TX_ADDR)");
> -	ASSERT_EQ(inet_pton(FAMILY, RX_ADDR, &iph->daddr), 1, "inet_pton(RX_ADDR)");
> -	ip_csum(iph);
> -
> -	udph->source = htons(AF_XDP_SOURCE_PORT);
> -	udph->dest = htons(dst_port);
> -	udph->len = htons(sizeof(*udph) + UDP_PAYLOAD_BYTES);
> -	udph->check = 0;
> -
> -	memset(udph + 1, 0xAA, UDP_PAYLOAD_BYTES);
> -
> -	tx_desc->len = sizeof(*eth) + sizeof(*iph) + sizeof(*udph) + UDP_PAYLOAD_BYTES;
> -	xsk_ring_prod__submit(&xsk->tx, 1);
> -
> -	ret = sendto(xsk_socket__fd(xsk->socket), NULL, 0, MSG_DONTWAIT, NULL, 0);
> -	if (!ASSERT_GE(ret, 0, "sendto"))
> -		return ret;
> -
> -	return 0;
> -}
> -
> -static void complete_tx(struct xsk *xsk)
> -{
> -	__u32 idx;
> -	__u64 addr;
> -
> -	if (ASSERT_EQ(xsk_ring_cons__peek(&xsk->comp, 1, &idx), 1, "xsk_ring_cons__peek")) {
> -		addr = *xsk_ring_cons__comp_addr(&xsk->comp, idx);
> -
> -		printf("%p: complete tx idx=%u addr=%llx\n", xsk, idx, addr);
> -		xsk_ring_cons__release(&xsk->comp, 1);
> -	}
> +	char udp_payload[UDP_PAYLOAD_BYTES];
> +	struct sockaddr_in rx_addr;
> +	int sock_fd, err = 0;
> +
> +	/* Build a packet */
> +	memset(udp_payload, 0xAA, UDP_PAYLOAD_BYTES);
> +	rx_addr.sin_addr.s_addr = inet_addr(RX_ADDR);
> +	rx_addr.sin_family = AF_INET;
> +	rx_addr.sin_port = htons(UDP_SOURCE_PORT);
> +
> +	sock_fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
> +	if (!ASSERT_GE(sock_fd, 0, "socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)"))
> +		return sock_fd;
> +
> +	err = sendto(sock_fd, udp_payload, UDP_PAYLOAD_BYTES, MSG_DONTWAIT,
> +		     (void *)&rx_addr, sizeof(rx_addr));
> +	ASSERT_GE(err, 0, "sendto");
> +
> +	close(sock_fd);
> +	return err;
>  }
>  
>  static void refill_rx(struct xsk *xsk, __u64 addr)
> @@ -268,7 +212,8 @@ static int verify_xsk_metadata(struct xsk *xsk)
>  	if (!ASSERT_NEQ(meta->rx_hash, 0, "rx_hash"))
>  		return -1;
>  
> -	ASSERT_EQ(meta->rx_hash_type, 0, "rx_hash_type");
> +	if (!ASSERT_NEQ(meta->rx_hash_type & XDP_RSS_TYPE_L4, 0, "rx_hash_type"))
> +		return -1;
>  
>  	xsk_ring_cons__release(&xsk->rx, 1);
>  	refill_rx(xsk, comp_addr);
> @@ -281,40 +226,46 @@ void test_xdp_metadata(void)
>  	struct xdp_metadata2 *bpf_obj2 = NULL;
>  	struct xdp_metadata *bpf_obj = NULL;
>  	struct bpf_program *new_prog, *prog;
> -	struct nstoken *tok = NULL;
> +	int prev_netns, rx_netns, tx_netns;
>  	__u32 queue_id = QUEUE_ID;
>  	struct bpf_map *prog_arr;
> -	struct xsk tx_xsk = {};
>  	struct xsk rx_xsk = {};
>  	__u32 val, key = 0;
>  	int retries = 10;
>  	int rx_ifindex;
> -	int tx_ifindex;
>  	int sock_fd;
>  	int ret;
>  
> -	/* Setup new networking namespace, with a veth pair. */
> +	/* Setup new networking namespaces, with a veth pair. */
>  
> -	SYS(out, "ip netns add xdp_metadata");
> -	tok = open_netns("xdp_metadata");
> +	SYS(out, "ip netns add " TX_NETNS_NAME);
> +	SYS(out, "ip netns add " RX_NETNS_NAME);
> +	prev_netns = get_cur_netns();
> +	tx_netns = get_netns(TX_NETNS_NAME);
> +	rx_netns = get_netns(RX_NETNS_NAME);
> +	if (prev_netns < 0 || tx_netns < 0 || rx_netns < 0)
> +		goto close_ns;
> +
> +	set_netns(tx_netns);
>  	SYS(out, "ip link add numtxqueues 1 numrxqueues 1 " TX_NAME
>  	    " type veth peer " RX_NAME " numtxqueues 1 numrxqueues 1");
> -	SYS(out, "ip link set dev " TX_NAME " address 00:00:00:00:00:01");
> -	SYS(out, "ip link set dev " RX_NAME " address 00:00:00:00:00:02");
> +	SYS(out, "ip link set " RX_NAME " netns " RX_NETNS_NAME);
> +
> +	SYS(out, "ip link set dev " TX_NAME " address " TX_MAC);
>  	SYS(out, "ip link set dev " TX_NAME " up");
> -	SYS(out, "ip link set dev " RX_NAME " up");
>  	SYS(out, "ip addr add " TX_ADDR "/" PREFIX_LEN " dev " TX_NAME);
> -	SYS(out, "ip addr add " RX_ADDR "/" PREFIX_LEN " dev " RX_NAME);
>  
> +	/* Avoid ARP calls */
> +	SYS(out, "ip -4 neigh add " RX_ADDR " lladdr " RX_MAC " dev " TX_NAME);
> +
> +	set_netns(rx_netns);
> +	SYS(out, "ip link set dev " RX_NAME " address " RX_MAC);
> +	SYS(out, "ip link set dev " RX_NAME " up");
> +	SYS(out, "ip addr add " RX_ADDR "/" PREFIX_LEN " dev " RX_NAME);
>  	rx_ifindex = if_nametoindex(RX_NAME);
> -	tx_ifindex = if_nametoindex(TX_NAME);
>  
>  	/* Setup separate AF_XDP for TX and RX interfaces. */
>  
> -	ret = open_xsk(tx_ifindex, &tx_xsk);
> -	if (!ASSERT_OK(ret, "open_xsk(TX_NAME)"))
> -		goto out;
> -
>  	ret = open_xsk(rx_ifindex, &rx_xsk);
>  	if (!ASSERT_OK(ret, "open_xsk(RX_NAME)"))
>  		goto out;
> @@ -355,17 +306,16 @@ void test_xdp_metadata(void)
>  		goto out;
>  
>  	/* Send packet destined to RX AF_XDP socket. */
> -	if (!ASSERT_GE(generate_packet(&tx_xsk, AF_XDP_CONSUMER_PORT), 0,
> -		       "generate AF_XDP_CONSUMER_PORT"))
> +	set_netns(tx_netns);
> +	if (!ASSERT_GE(generate_packet_udp(), 0, "generate UDP packet"))
>  		goto out;
>  
>  	/* Verify AF_XDP RX packet has proper metadata. */
> +	set_netns(rx_netns);
>  	if (!ASSERT_GE(verify_xsk_metadata(&rx_xsk), 0,
>  		       "verify_xsk_metadata"))
>  		goto out;
>  
> -	complete_tx(&tx_xsk);
> -
>  	/* Make sure freplace correctly picks up original bound device
>  	 * and doesn't crash.
>  	 */
> @@ -384,10 +334,11 @@ void test_xdp_metadata(void)
>  		goto out;
>  
>  	/* Send packet to trigger . */
> -	if (!ASSERT_GE(generate_packet(&tx_xsk, AF_XDP_CONSUMER_PORT), 0,
> -		       "generate freplace packet"))
> +	set_netns(tx_netns);
> +	if (!ASSERT_GE(generate_packet_udp(), 0, "generate freplace packet"))
>  		goto out;
>  
> +	set_netns(rx_netns);
>  	while (!retries--) {
>  		if (bpf_obj2->bss->called)
>  			break;
> @@ -397,10 +348,14 @@ void test_xdp_metadata(void)
>  
>  out:
>  	close_xsk(&rx_xsk);
> -	close_xsk(&tx_xsk);
>  	xdp_metadata2__destroy(bpf_obj2);
>  	xdp_metadata__destroy(bpf_obj);
> -	if (tok)
> -		close_netns(tok);
> -	SYS_NOFAIL("ip netns del xdp_metadata");
> +	set_netns(prev_netns);
> +close_ns:
> +	close(prev_netns);
> +	close(tx_netns);
> +	close(rx_netns);
> +
> +	SYS_NOFAIL("ip netns del " RX_NETNS_NAME);
> +	SYS_NOFAIL("ip netns del " TX_NETNS_NAME);
>  }
> -- 
> 2.41.0
>
Larysa Zaremba July 6, 2023, 2:11 p.m. UTC | #2
On Wed, Jul 05, 2023 at 10:39:35AM -0700, Stanislav Fomichev wrote:
> On 07/03, Larysa Zaremba wrote:
> > The easiest way to simulate stripped VLAN tag in veth is to send a packet
> > from VLAN interface, attached to veth. Unfortunately, this approach is
> > incompatible with AF_XDP on TX side, because VLAN interfaces do not have
> > such feature.
> > 
> > Replace AF_XDP packet generation with sending the same datagram via
> > AF_INET socket.
> > 
> > This does not change the packet contents or hints values with one notable
> > exception: rx_hash_type, which previously was expected to be 0, now is
> > expected be at least XDP_RSS_TYPE_L4.
> > 
> > Also, usage of AF_INET requires a little more complicated namespace setup,
> > therefore open_netns() helper function is divided into smaller reusable
> > pieces.
> 
> Ack, it's probably OK for now, but, FYI, I'm trying to extend this part
> with TX metadata:
> https://lore.kernel.org/bpf/20230621170244.1283336-10-sdf@google.com/
> 
> So probably long-term I'll switch it back to AF_XDP but will add
> support for requesting vlan TX "offload" from the veth.
>

My bad for not reading your series. Amazing work as always!

So, 'requesting vlan TX "offload"' with new hints capabilities? This would be 
pretty neat.

But you think AF_INET TX is worth keeping for now, until TX hints are mature?
  
> > Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
> > ---
> >  tools/testing/selftests/bpf/network_helpers.c |  37 +++-
> >  tools/testing/selftests/bpf/network_helpers.h |   3 +
> >  .../selftests/bpf/prog_tests/xdp_metadata.c   | 175 +++++++-----------
> >  3 files changed, 98 insertions(+), 117 deletions(-)
> > 
> > diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c
> > index a105c0cd008a..19463230ece5 100644
> > --- a/tools/testing/selftests/bpf/network_helpers.c
> > +++ b/tools/testing/selftests/bpf/network_helpers.c
> > @@ -386,28 +386,51 @@ char *ping_command(int family)
> >  	return "ping";
> >  }
> >  
> > +int get_cur_netns(void)
> > +{
> > +	int nsfd;
> > +
> > +	nsfd = open("/proc/self/ns/net", O_RDONLY);
> > +	ASSERT_GE(nsfd, 0, "open /proc/self/ns/net");
> > +	return nsfd;
> > +}
> > +
> > +int get_netns(const char *name)
> > +{
> > +	char nspath[PATH_MAX];
> > +	int nsfd;
> > +
> > +	snprintf(nspath, sizeof(nspath), "%s/%s", "/var/run/netns", name);
> > +	nsfd = open(nspath, O_RDONLY | O_CLOEXEC);
> > +	ASSERT_GE(nsfd, 0, "open /proc/self/ns/net");
> > +	return nsfd;
> > +}
> > +
> > +int set_netns(int netns_fd)
> > +{
> > +	return setns(netns_fd, CLONE_NEWNET);
> > +}
> 
> We have open_netns/close_netns in network_helpers.h that provide similar
> functionality, let's use them instead?
> 

I have divided open_netns() into smaller pieces (see below), because the code I 
have added into xdp_metadata looked better with those smaller pieces (I had to 
switch namespace several times).

> > +
> >  struct nstoken {
> >  	int orig_netns_fd;
> >  };
> >  
> >  struct nstoken *open_netns(const char *name)
> >  {
> > +	struct nstoken *token;
> >  	int nsfd;
> > -	char nspath[PATH_MAX];
> >  	int err;
> > -	struct nstoken *token;
> >  
> >  	token = calloc(1, sizeof(struct nstoken));
> >  	if (!ASSERT_OK_PTR(token, "malloc token"))
> >  		return NULL;
> >  
> > -	token->orig_netns_fd = open("/proc/self/ns/net", O_RDONLY);
> > -	if (!ASSERT_GE(token->orig_netns_fd, 0, "open /proc/self/ns/net"))
> > +	token->orig_netns_fd = get_cur_netns();
> > +	if (token->orig_netns_fd < 0)
> >  		goto fail;
> >  
> > -	snprintf(nspath, sizeof(nspath), "%s/%s", "/var/run/netns", name);
> > -	nsfd = open(nspath, O_RDONLY | O_CLOEXEC);
> > -	if (!ASSERT_GE(nsfd, 0, "open netns fd"))
> > +	nsfd = get_netns(name);
> > +	if (nsfd < 0)
> >  		goto fail;
> >  
> >  	err = setns(nsfd, CLONE_NEWNET);
> > diff --git a/tools/testing/selftests/bpf/network_helpers.h b/tools/testing/selftests/bpf/network_helpers.h
> > index 694185644da6..b18b9619595c 100644
> > --- a/tools/testing/selftests/bpf/network_helpers.h
> > +++ b/tools/testing/selftests/bpf/network_helpers.h
> > @@ -58,6 +58,8 @@ int make_sockaddr(int family, const char *addr_str, __u16 port,
> >  char *ping_command(int family);
> >  int get_socket_local_port(int sock_fd);
> >  
> > +int get_cur_netns(void);
> > +int get_netns(const char *name);
> >  struct nstoken;
> >  /**
> >   * open_netns() - Switch to specified network namespace by name.
> > @@ -67,4 +69,5 @@ struct nstoken;
> >   */
> >  struct nstoken *open_netns(const char *name);
> >  void close_netns(struct nstoken *token);
> > +int set_netns(int netns_fd);
> >  #endif
> > diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
> > index 626c461fa34d..53b32a641e8e 100644
> > --- a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
> > +++ b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
> > @@ -20,7 +20,7 @@
> >  
> >  #define UDP_PAYLOAD_BYTES 4
> >  
> > -#define AF_XDP_SOURCE_PORT 1234
> > +#define UDP_SOURCE_PORT 1234
> >  #define AF_XDP_CONSUMER_PORT 8080
> >  
> >  #define UMEM_NUM 16
> > @@ -33,6 +33,12 @@
> >  #define RX_ADDR "10.0.0.2"
> >  #define PREFIX_LEN "8"
> >  #define FAMILY AF_INET
> > +#define TX_NETNS_NAME "xdp_metadata_tx"
> > +#define RX_NETNS_NAME "xdp_metadata_rx"
> > +#define TX_MAC "00:00:00:00:00:01"
> > +#define RX_MAC "00:00:00:00:00:02"
> > +
> > +#define XDP_RSS_TYPE_L4 BIT(3)
> >  
> >  struct xsk {
> >  	void *umem_area;
> > @@ -119,90 +125,28 @@ static void close_xsk(struct xsk *xsk)
> >  	munmap(xsk->umem_area, UMEM_SIZE);
> >  }
> >  
> > -static void ip_csum(struct iphdr *iph)
> > +static int generate_packet_udp(void)
> >  {
> > -	__u32 sum = 0;
> > -	__u16 *p;
> > -	int i;
> > -
> > -	iph->check = 0;
> > -	p = (void *)iph;
> > -	for (i = 0; i < sizeof(*iph) / sizeof(*p); i++)
> > -		sum += p[i];
> > -
> > -	while (sum >> 16)
> > -		sum = (sum & 0xffff) + (sum >> 16);
> > -
> > -	iph->check = ~sum;
> > -}
> > -
> > -static int generate_packet(struct xsk *xsk, __u16 dst_port)
> > -{
> > -	struct xdp_desc *tx_desc;
> > -	struct udphdr *udph;
> > -	struct ethhdr *eth;
> > -	struct iphdr *iph;
> > -	void *data;
> > -	__u32 idx;
> > -	int ret;
> > -
> > -	ret = xsk_ring_prod__reserve(&xsk->tx, 1, &idx);
> > -	if (!ASSERT_EQ(ret, 1, "xsk_ring_prod__reserve"))
> > -		return -1;
> > -
> > -	tx_desc = xsk_ring_prod__tx_desc(&xsk->tx, idx);
> > -	tx_desc->addr = idx % (UMEM_NUM / 2) * UMEM_FRAME_SIZE;
> > -	printf("%p: tx_desc[%u]->addr=%llx\n", xsk, idx, tx_desc->addr);
> > -	data = xsk_umem__get_data(xsk->umem_area, tx_desc->addr);
> > -
> > -	eth = data;
> > -	iph = (void *)(eth + 1);
> > -	udph = (void *)(iph + 1);
> > -
> > -	memcpy(eth->h_dest, "\x00\x00\x00\x00\x00\x02", ETH_ALEN);
> > -	memcpy(eth->h_source, "\x00\x00\x00\x00\x00\x01", ETH_ALEN);
> > -	eth->h_proto = htons(ETH_P_IP);
> > -
> > -	iph->version = 0x4;
> > -	iph->ihl = 0x5;
> > -	iph->tos = 0x9;
> > -	iph->tot_len = htons(sizeof(*iph) + sizeof(*udph) + UDP_PAYLOAD_BYTES);
> > -	iph->id = 0;
> > -	iph->frag_off = 0;
> > -	iph->ttl = 0;
> > -	iph->protocol = IPPROTO_UDP;
> > -	ASSERT_EQ(inet_pton(FAMILY, TX_ADDR, &iph->saddr), 1, "inet_pton(TX_ADDR)");
> > -	ASSERT_EQ(inet_pton(FAMILY, RX_ADDR, &iph->daddr), 1, "inet_pton(RX_ADDR)");
> > -	ip_csum(iph);
> > -
> > -	udph->source = htons(AF_XDP_SOURCE_PORT);
> > -	udph->dest = htons(dst_port);
> > -	udph->len = htons(sizeof(*udph) + UDP_PAYLOAD_BYTES);
> > -	udph->check = 0;
> > -
> > -	memset(udph + 1, 0xAA, UDP_PAYLOAD_BYTES);
> > -
> > -	tx_desc->len = sizeof(*eth) + sizeof(*iph) + sizeof(*udph) + UDP_PAYLOAD_BYTES;
> > -	xsk_ring_prod__submit(&xsk->tx, 1);
> > -
> > -	ret = sendto(xsk_socket__fd(xsk->socket), NULL, 0, MSG_DONTWAIT, NULL, 0);
> > -	if (!ASSERT_GE(ret, 0, "sendto"))
> > -		return ret;
> > -
> > -	return 0;
> > -}
> > -
> > -static void complete_tx(struct xsk *xsk)
> > -{
> > -	__u32 idx;
> > -	__u64 addr;
> > -
> > -	if (ASSERT_EQ(xsk_ring_cons__peek(&xsk->comp, 1, &idx), 1, "xsk_ring_cons__peek")) {
> > -		addr = *xsk_ring_cons__comp_addr(&xsk->comp, idx);
> > -
> > -		printf("%p: complete tx idx=%u addr=%llx\n", xsk, idx, addr);
> > -		xsk_ring_cons__release(&xsk->comp, 1);
> > -	}
> > +	char udp_payload[UDP_PAYLOAD_BYTES];
> > +	struct sockaddr_in rx_addr;
> > +	int sock_fd, err = 0;
> > +
> > +	/* Build a packet */
> > +	memset(udp_payload, 0xAA, UDP_PAYLOAD_BYTES);
> > +	rx_addr.sin_addr.s_addr = inet_addr(RX_ADDR);
> > +	rx_addr.sin_family = AF_INET;
> > +	rx_addr.sin_port = htons(UDP_SOURCE_PORT);
> > +
> > +	sock_fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
> > +	if (!ASSERT_GE(sock_fd, 0, "socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)"))
> > +		return sock_fd;
> > +
> > +	err = sendto(sock_fd, udp_payload, UDP_PAYLOAD_BYTES, MSG_DONTWAIT,
> > +		     (void *)&rx_addr, sizeof(rx_addr));
> > +	ASSERT_GE(err, 0, "sendto");
> > +
> > +	close(sock_fd);
> > +	return err;
> >  }
> >  
> >  static void refill_rx(struct xsk *xsk, __u64 addr)
> > @@ -268,7 +212,8 @@ static int verify_xsk_metadata(struct xsk *xsk)
> >  	if (!ASSERT_NEQ(meta->rx_hash, 0, "rx_hash"))
> >  		return -1;
> >  
> > -	ASSERT_EQ(meta->rx_hash_type, 0, "rx_hash_type");
> > +	if (!ASSERT_NEQ(meta->rx_hash_type & XDP_RSS_TYPE_L4, 0, "rx_hash_type"))
> > +		return -1;
> >  
> >  	xsk_ring_cons__release(&xsk->rx, 1);
> >  	refill_rx(xsk, comp_addr);
> > @@ -281,40 +226,46 @@ void test_xdp_metadata(void)
> >  	struct xdp_metadata2 *bpf_obj2 = NULL;
> >  	struct xdp_metadata *bpf_obj = NULL;
> >  	struct bpf_program *new_prog, *prog;
> > -	struct nstoken *tok = NULL;
> > +	int prev_netns, rx_netns, tx_netns;
> >  	__u32 queue_id = QUEUE_ID;
> >  	struct bpf_map *prog_arr;
> > -	struct xsk tx_xsk = {};
> >  	struct xsk rx_xsk = {};
> >  	__u32 val, key = 0;
> >  	int retries = 10;
> >  	int rx_ifindex;
> > -	int tx_ifindex;
> >  	int sock_fd;
> >  	int ret;
> >  
> > -	/* Setup new networking namespace, with a veth pair. */
> > +	/* Setup new networking namespaces, with a veth pair. */
> >  
> > -	SYS(out, "ip netns add xdp_metadata");
> > -	tok = open_netns("xdp_metadata");
> > +	SYS(out, "ip netns add " TX_NETNS_NAME);
> > +	SYS(out, "ip netns add " RX_NETNS_NAME);
> > +	prev_netns = get_cur_netns();
> > +	tx_netns = get_netns(TX_NETNS_NAME);
> > +	rx_netns = get_netns(RX_NETNS_NAME);
> > +	if (prev_netns < 0 || tx_netns < 0 || rx_netns < 0)
> > +		goto close_ns;
> > +
> > +	set_netns(tx_netns);
> >  	SYS(out, "ip link add numtxqueues 1 numrxqueues 1 " TX_NAME
> >  	    " type veth peer " RX_NAME " numtxqueues 1 numrxqueues 1");
> > -	SYS(out, "ip link set dev " TX_NAME " address 00:00:00:00:00:01");
> > -	SYS(out, "ip link set dev " RX_NAME " address 00:00:00:00:00:02");
> > +	SYS(out, "ip link set " RX_NAME " netns " RX_NETNS_NAME);
> > +
> > +	SYS(out, "ip link set dev " TX_NAME " address " TX_MAC);
> >  	SYS(out, "ip link set dev " TX_NAME " up");
> > -	SYS(out, "ip link set dev " RX_NAME " up");
> >  	SYS(out, "ip addr add " TX_ADDR "/" PREFIX_LEN " dev " TX_NAME);
> > -	SYS(out, "ip addr add " RX_ADDR "/" PREFIX_LEN " dev " RX_NAME);
> >  
> > +	/* Avoid ARP calls */
> > +	SYS(out, "ip -4 neigh add " RX_ADDR " lladdr " RX_MAC " dev " TX_NAME);
> > +
> > +	set_netns(rx_netns);
> > +	SYS(out, "ip link set dev " RX_NAME " address " RX_MAC);
> > +	SYS(out, "ip link set dev " RX_NAME " up");
> > +	SYS(out, "ip addr add " RX_ADDR "/" PREFIX_LEN " dev " RX_NAME);
> >  	rx_ifindex = if_nametoindex(RX_NAME);
> > -	tx_ifindex = if_nametoindex(TX_NAME);
> >  
> >  	/* Setup separate AF_XDP for TX and RX interfaces. */
> >  
> > -	ret = open_xsk(tx_ifindex, &tx_xsk);
> > -	if (!ASSERT_OK(ret, "open_xsk(TX_NAME)"))
> > -		goto out;
> > -
> >  	ret = open_xsk(rx_ifindex, &rx_xsk);
> >  	if (!ASSERT_OK(ret, "open_xsk(RX_NAME)"))
> >  		goto out;
> > @@ -355,17 +306,16 @@ void test_xdp_metadata(void)
> >  		goto out;
> >  
> >  	/* Send packet destined to RX AF_XDP socket. */
> > -	if (!ASSERT_GE(generate_packet(&tx_xsk, AF_XDP_CONSUMER_PORT), 0,
> > -		       "generate AF_XDP_CONSUMER_PORT"))
> > +	set_netns(tx_netns);
> > +	if (!ASSERT_GE(generate_packet_udp(), 0, "generate UDP packet"))
> >  		goto out;
> >  
> >  	/* Verify AF_XDP RX packet has proper metadata. */
> > +	set_netns(rx_netns);
> >  	if (!ASSERT_GE(verify_xsk_metadata(&rx_xsk), 0,
> >  		       "verify_xsk_metadata"))
> >  		goto out;
> >  
> > -	complete_tx(&tx_xsk);
> > -
> >  	/* Make sure freplace correctly picks up original bound device
> >  	 * and doesn't crash.
> >  	 */
> > @@ -384,10 +334,11 @@ void test_xdp_metadata(void)
> >  		goto out;
> >  
> >  	/* Send packet to trigger . */
> > -	if (!ASSERT_GE(generate_packet(&tx_xsk, AF_XDP_CONSUMER_PORT), 0,
> > -		       "generate freplace packet"))
> > +	set_netns(tx_netns);
> > +	if (!ASSERT_GE(generate_packet_udp(), 0, "generate freplace packet"))
> >  		goto out;
> >  
> > +	set_netns(rx_netns);
> >  	while (!retries--) {
> >  		if (bpf_obj2->bss->called)
> >  			break;
> > @@ -397,10 +348,14 @@ void test_xdp_metadata(void)
> >  
> >  out:
> >  	close_xsk(&rx_xsk);
> > -	close_xsk(&tx_xsk);
> >  	xdp_metadata2__destroy(bpf_obj2);
> >  	xdp_metadata__destroy(bpf_obj);
> > -	if (tok)
> > -		close_netns(tok);
> > -	SYS_NOFAIL("ip netns del xdp_metadata");
> > +	set_netns(prev_netns);
> > +close_ns:
> > +	close(prev_netns);
> > +	close(tx_netns);
> > +	close(rx_netns);
> > +
> > +	SYS_NOFAIL("ip netns del " RX_NETNS_NAME);
> > +	SYS_NOFAIL("ip netns del " TX_NETNS_NAME);
> >  }
> > -- 
> > 2.41.0
> >
Stanislav Fomichev July 6, 2023, 5:25 p.m. UTC | #3
On Thu, Jul 6, 2023 at 7:15 AM Larysa Zaremba <larysa.zaremba@intel.com> wrote:
>
> On Wed, Jul 05, 2023 at 10:39:35AM -0700, Stanislav Fomichev wrote:
> > On 07/03, Larysa Zaremba wrote:
> > > The easiest way to simulate stripped VLAN tag in veth is to send a packet
> > > from VLAN interface, attached to veth. Unfortunately, this approach is
> > > incompatible with AF_XDP on TX side, because VLAN interfaces do not have
> > > such feature.
> > >
> > > Replace AF_XDP packet generation with sending the same datagram via
> > > AF_INET socket.
> > >
> > > This does not change the packet contents or hints values with one notable
> > > exception: rx_hash_type, which previously was expected to be 0, now is
> > > expected be at least XDP_RSS_TYPE_L4.
> > >
> > > Also, usage of AF_INET requires a little more complicated namespace setup,
> > > therefore open_netns() helper function is divided into smaller reusable
> > > pieces.
> >
> > Ack, it's probably OK for now, but, FYI, I'm trying to extend this part
> > with TX metadata:
> > https://lore.kernel.org/bpf/20230621170244.1283336-10-sdf@google.com/
> >
> > So probably long-term I'll switch it back to AF_XDP but will add
> > support for requesting vlan TX "offload" from the veth.
> >
>
> My bad for not reading your series. Amazing work as always!
>
> So, 'requesting vlan TX "offload"' with new hints capabilities? This would be
> pretty neat.
>
> But you think AF_INET TX is worth keeping for now, until TX hints are mature?

It's fine to replace current af_xdp tx with whatever you're suggesting.
I can bring it back later for tx when it's ready.


> > > Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
> > > ---
> > >  tools/testing/selftests/bpf/network_helpers.c |  37 +++-
> > >  tools/testing/selftests/bpf/network_helpers.h |   3 +
> > >  .../selftests/bpf/prog_tests/xdp_metadata.c   | 175 +++++++-----------
> > >  3 files changed, 98 insertions(+), 117 deletions(-)
> > >
> > > diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c
> > > index a105c0cd008a..19463230ece5 100644
> > > --- a/tools/testing/selftests/bpf/network_helpers.c
> > > +++ b/tools/testing/selftests/bpf/network_helpers.c
> > > @@ -386,28 +386,51 @@ char *ping_command(int family)
> > >     return "ping";
> > >  }
> > >
> > > +int get_cur_netns(void)
> > > +{
> > > +   int nsfd;
> > > +
> > > +   nsfd = open("/proc/self/ns/net", O_RDONLY);
> > > +   ASSERT_GE(nsfd, 0, "open /proc/self/ns/net");
> > > +   return nsfd;
> > > +}
> > > +
> > > +int get_netns(const char *name)
> > > +{
> > > +   char nspath[PATH_MAX];
> > > +   int nsfd;
> > > +
> > > +   snprintf(nspath, sizeof(nspath), "%s/%s", "/var/run/netns", name);
> > > +   nsfd = open(nspath, O_RDONLY | O_CLOEXEC);
> > > +   ASSERT_GE(nsfd, 0, "open /proc/self/ns/net");
> > > +   return nsfd;
> > > +}
> > > +
> > > +int set_netns(int netns_fd)
> > > +{
> > > +   return setns(netns_fd, CLONE_NEWNET);
> > > +}
> >
> > We have open_netns/close_netns in network_helpers.h that provide similar
> > functionality, let's use them instead?
> >
>
> I have divided open_netns() into smaller pieces (see below), because the code I
> have added into xdp_metadata looked better with those smaller pieces (I had to
> switch namespace several times).
>
> > > +
> > >  struct nstoken {
> > >     int orig_netns_fd;
> > >  };
> > >
> > >  struct nstoken *open_netns(const char *name)
> > >  {
> > > +   struct nstoken *token;
> > >     int nsfd;
> > > -   char nspath[PATH_MAX];
> > >     int err;
> > > -   struct nstoken *token;
> > >
> > >     token = calloc(1, sizeof(struct nstoken));
> > >     if (!ASSERT_OK_PTR(token, "malloc token"))
> > >             return NULL;
> > >
> > > -   token->orig_netns_fd = open("/proc/self/ns/net", O_RDONLY);
> > > -   if (!ASSERT_GE(token->orig_netns_fd, 0, "open /proc/self/ns/net"))
> > > +   token->orig_netns_fd = get_cur_netns();
> > > +   if (token->orig_netns_fd < 0)
> > >             goto fail;
> > >
> > > -   snprintf(nspath, sizeof(nspath), "%s/%s", "/var/run/netns", name);
> > > -   nsfd = open(nspath, O_RDONLY | O_CLOEXEC);
> > > -   if (!ASSERT_GE(nsfd, 0, "open netns fd"))
> > > +   nsfd = get_netns(name);
> > > +   if (nsfd < 0)
> > >             goto fail;
> > >
> > >     err = setns(nsfd, CLONE_NEWNET);
> > > diff --git a/tools/testing/selftests/bpf/network_helpers.h b/tools/testing/selftests/bpf/network_helpers.h
> > > index 694185644da6..b18b9619595c 100644
> > > --- a/tools/testing/selftests/bpf/network_helpers.h
> > > +++ b/tools/testing/selftests/bpf/network_helpers.h
> > > @@ -58,6 +58,8 @@ int make_sockaddr(int family, const char *addr_str, __u16 port,
> > >  char *ping_command(int family);
> > >  int get_socket_local_port(int sock_fd);
> > >
> > > +int get_cur_netns(void);
> > > +int get_netns(const char *name);
> > >  struct nstoken;
> > >  /**
> > >   * open_netns() - Switch to specified network namespace by name.
> > > @@ -67,4 +69,5 @@ struct nstoken;
> > >   */
> > >  struct nstoken *open_netns(const char *name);
> > >  void close_netns(struct nstoken *token);
> > > +int set_netns(int netns_fd);
> > >  #endif
> > > diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
> > > index 626c461fa34d..53b32a641e8e 100644
> > > --- a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
> > > +++ b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
> > > @@ -20,7 +20,7 @@
> > >
> > >  #define UDP_PAYLOAD_BYTES 4
> > >
> > > -#define AF_XDP_SOURCE_PORT 1234
> > > +#define UDP_SOURCE_PORT 1234
> > >  #define AF_XDP_CONSUMER_PORT 8080
> > >
> > >  #define UMEM_NUM 16
> > > @@ -33,6 +33,12 @@
> > >  #define RX_ADDR "10.0.0.2"
> > >  #define PREFIX_LEN "8"
> > >  #define FAMILY AF_INET
> > > +#define TX_NETNS_NAME "xdp_metadata_tx"
> > > +#define RX_NETNS_NAME "xdp_metadata_rx"
> > > +#define TX_MAC "00:00:00:00:00:01"
> > > +#define RX_MAC "00:00:00:00:00:02"
> > > +
> > > +#define XDP_RSS_TYPE_L4 BIT(3)
> > >
> > >  struct xsk {
> > >     void *umem_area;
> > > @@ -119,90 +125,28 @@ static void close_xsk(struct xsk *xsk)
> > >     munmap(xsk->umem_area, UMEM_SIZE);
> > >  }
> > >
> > > -static void ip_csum(struct iphdr *iph)
> > > +static int generate_packet_udp(void)
> > >  {
> > > -   __u32 sum = 0;
> > > -   __u16 *p;
> > > -   int i;
> > > -
> > > -   iph->check = 0;
> > > -   p = (void *)iph;
> > > -   for (i = 0; i < sizeof(*iph) / sizeof(*p); i++)
> > > -           sum += p[i];
> > > -
> > > -   while (sum >> 16)
> > > -           sum = (sum & 0xffff) + (sum >> 16);
> > > -
> > > -   iph->check = ~sum;
> > > -}
> > > -
> > > -static int generate_packet(struct xsk *xsk, __u16 dst_port)
> > > -{
> > > -   struct xdp_desc *tx_desc;
> > > -   struct udphdr *udph;
> > > -   struct ethhdr *eth;
> > > -   struct iphdr *iph;
> > > -   void *data;
> > > -   __u32 idx;
> > > -   int ret;
> > > -
> > > -   ret = xsk_ring_prod__reserve(&xsk->tx, 1, &idx);
> > > -   if (!ASSERT_EQ(ret, 1, "xsk_ring_prod__reserve"))
> > > -           return -1;
> > > -
> > > -   tx_desc = xsk_ring_prod__tx_desc(&xsk->tx, idx);
> > > -   tx_desc->addr = idx % (UMEM_NUM / 2) * UMEM_FRAME_SIZE;
> > > -   printf("%p: tx_desc[%u]->addr=%llx\n", xsk, idx, tx_desc->addr);
> > > -   data = xsk_umem__get_data(xsk->umem_area, tx_desc->addr);
> > > -
> > > -   eth = data;
> > > -   iph = (void *)(eth + 1);
> > > -   udph = (void *)(iph + 1);
> > > -
> > > -   memcpy(eth->h_dest, "\x00\x00\x00\x00\x00\x02", ETH_ALEN);
> > > -   memcpy(eth->h_source, "\x00\x00\x00\x00\x00\x01", ETH_ALEN);
> > > -   eth->h_proto = htons(ETH_P_IP);
> > > -
> > > -   iph->version = 0x4;
> > > -   iph->ihl = 0x5;
> > > -   iph->tos = 0x9;
> > > -   iph->tot_len = htons(sizeof(*iph) + sizeof(*udph) + UDP_PAYLOAD_BYTES);
> > > -   iph->id = 0;
> > > -   iph->frag_off = 0;
> > > -   iph->ttl = 0;
> > > -   iph->protocol = IPPROTO_UDP;
> > > -   ASSERT_EQ(inet_pton(FAMILY, TX_ADDR, &iph->saddr), 1, "inet_pton(TX_ADDR)");
> > > -   ASSERT_EQ(inet_pton(FAMILY, RX_ADDR, &iph->daddr), 1, "inet_pton(RX_ADDR)");
> > > -   ip_csum(iph);
> > > -
> > > -   udph->source = htons(AF_XDP_SOURCE_PORT);
> > > -   udph->dest = htons(dst_port);
> > > -   udph->len = htons(sizeof(*udph) + UDP_PAYLOAD_BYTES);
> > > -   udph->check = 0;
> > > -
> > > -   memset(udph + 1, 0xAA, UDP_PAYLOAD_BYTES);
> > > -
> > > -   tx_desc->len = sizeof(*eth) + sizeof(*iph) + sizeof(*udph) + UDP_PAYLOAD_BYTES;
> > > -   xsk_ring_prod__submit(&xsk->tx, 1);
> > > -
> > > -   ret = sendto(xsk_socket__fd(xsk->socket), NULL, 0, MSG_DONTWAIT, NULL, 0);
> > > -   if (!ASSERT_GE(ret, 0, "sendto"))
> > > -           return ret;
> > > -
> > > -   return 0;
> > > -}
> > > -
> > > -static void complete_tx(struct xsk *xsk)
> > > -{
> > > -   __u32 idx;
> > > -   __u64 addr;
> > > -
> > > -   if (ASSERT_EQ(xsk_ring_cons__peek(&xsk->comp, 1, &idx), 1, "xsk_ring_cons__peek")) {
> > > -           addr = *xsk_ring_cons__comp_addr(&xsk->comp, idx);
> > > -
> > > -           printf("%p: complete tx idx=%u addr=%llx\n", xsk, idx, addr);
> > > -           xsk_ring_cons__release(&xsk->comp, 1);
> > > -   }
> > > +   char udp_payload[UDP_PAYLOAD_BYTES];
> > > +   struct sockaddr_in rx_addr;
> > > +   int sock_fd, err = 0;
> > > +
> > > +   /* Build a packet */
> > > +   memset(udp_payload, 0xAA, UDP_PAYLOAD_BYTES);
> > > +   rx_addr.sin_addr.s_addr = inet_addr(RX_ADDR);
> > > +   rx_addr.sin_family = AF_INET;
> > > +   rx_addr.sin_port = htons(UDP_SOURCE_PORT);
> > > +
> > > +   sock_fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
> > > +   if (!ASSERT_GE(sock_fd, 0, "socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)"))
> > > +           return sock_fd;
> > > +
> > > +   err = sendto(sock_fd, udp_payload, UDP_PAYLOAD_BYTES, MSG_DONTWAIT,
> > > +                (void *)&rx_addr, sizeof(rx_addr));
> > > +   ASSERT_GE(err, 0, "sendto");
> > > +
> > > +   close(sock_fd);
> > > +   return err;
> > >  }
> > >
> > >  static void refill_rx(struct xsk *xsk, __u64 addr)
> > > @@ -268,7 +212,8 @@ static int verify_xsk_metadata(struct xsk *xsk)
> > >     if (!ASSERT_NEQ(meta->rx_hash, 0, "rx_hash"))
> > >             return -1;
> > >
> > > -   ASSERT_EQ(meta->rx_hash_type, 0, "rx_hash_type");
> > > +   if (!ASSERT_NEQ(meta->rx_hash_type & XDP_RSS_TYPE_L4, 0, "rx_hash_type"))
> > > +           return -1;
> > >
> > >     xsk_ring_cons__release(&xsk->rx, 1);
> > >     refill_rx(xsk, comp_addr);
> > > @@ -281,40 +226,46 @@ void test_xdp_metadata(void)
> > >     struct xdp_metadata2 *bpf_obj2 = NULL;
> > >     struct xdp_metadata *bpf_obj = NULL;
> > >     struct bpf_program *new_prog, *prog;
> > > -   struct nstoken *tok = NULL;
> > > +   int prev_netns, rx_netns, tx_netns;
> > >     __u32 queue_id = QUEUE_ID;
> > >     struct bpf_map *prog_arr;
> > > -   struct xsk tx_xsk = {};
> > >     struct xsk rx_xsk = {};
> > >     __u32 val, key = 0;
> > >     int retries = 10;
> > >     int rx_ifindex;
> > > -   int tx_ifindex;
> > >     int sock_fd;
> > >     int ret;
> > >
> > > -   /* Setup new networking namespace, with a veth pair. */
> > > +   /* Setup new networking namespaces, with a veth pair. */
> > >
> > > -   SYS(out, "ip netns add xdp_metadata");
> > > -   tok = open_netns("xdp_metadata");
> > > +   SYS(out, "ip netns add " TX_NETNS_NAME);
> > > +   SYS(out, "ip netns add " RX_NETNS_NAME);
> > > +   prev_netns = get_cur_netns();
> > > +   tx_netns = get_netns(TX_NETNS_NAME);
> > > +   rx_netns = get_netns(RX_NETNS_NAME);
> > > +   if (prev_netns < 0 || tx_netns < 0 || rx_netns < 0)
> > > +           goto close_ns;
> > > +
> > > +   set_netns(tx_netns);
> > >     SYS(out, "ip link add numtxqueues 1 numrxqueues 1 " TX_NAME
> > >         " type veth peer " RX_NAME " numtxqueues 1 numrxqueues 1");
> > > -   SYS(out, "ip link set dev " TX_NAME " address 00:00:00:00:00:01");
> > > -   SYS(out, "ip link set dev " RX_NAME " address 00:00:00:00:00:02");
> > > +   SYS(out, "ip link set " RX_NAME " netns " RX_NETNS_NAME);
> > > +
> > > +   SYS(out, "ip link set dev " TX_NAME " address " TX_MAC);
> > >     SYS(out, "ip link set dev " TX_NAME " up");
> > > -   SYS(out, "ip link set dev " RX_NAME " up");
> > >     SYS(out, "ip addr add " TX_ADDR "/" PREFIX_LEN " dev " TX_NAME);
> > > -   SYS(out, "ip addr add " RX_ADDR "/" PREFIX_LEN " dev " RX_NAME);
> > >
> > > +   /* Avoid ARP calls */
> > > +   SYS(out, "ip -4 neigh add " RX_ADDR " lladdr " RX_MAC " dev " TX_NAME);
> > > +
> > > +   set_netns(rx_netns);
> > > +   SYS(out, "ip link set dev " RX_NAME " address " RX_MAC);
> > > +   SYS(out, "ip link set dev " RX_NAME " up");
> > > +   SYS(out, "ip addr add " RX_ADDR "/" PREFIX_LEN " dev " RX_NAME);
> > >     rx_ifindex = if_nametoindex(RX_NAME);
> > > -   tx_ifindex = if_nametoindex(TX_NAME);
> > >
> > >     /* Setup separate AF_XDP for TX and RX interfaces. */
> > >
> > > -   ret = open_xsk(tx_ifindex, &tx_xsk);
> > > -   if (!ASSERT_OK(ret, "open_xsk(TX_NAME)"))
> > > -           goto out;
> > > -
> > >     ret = open_xsk(rx_ifindex, &rx_xsk);
> > >     if (!ASSERT_OK(ret, "open_xsk(RX_NAME)"))
> > >             goto out;
> > > @@ -355,17 +306,16 @@ void test_xdp_metadata(void)
> > >             goto out;
> > >
> > >     /* Send packet destined to RX AF_XDP socket. */
> > > -   if (!ASSERT_GE(generate_packet(&tx_xsk, AF_XDP_CONSUMER_PORT), 0,
> > > -                  "generate AF_XDP_CONSUMER_PORT"))
> > > +   set_netns(tx_netns);
> > > +   if (!ASSERT_GE(generate_packet_udp(), 0, "generate UDP packet"))
> > >             goto out;
> > >
> > >     /* Verify AF_XDP RX packet has proper metadata. */
> > > +   set_netns(rx_netns);
> > >     if (!ASSERT_GE(verify_xsk_metadata(&rx_xsk), 0,
> > >                    "verify_xsk_metadata"))
> > >             goto out;
> > >
> > > -   complete_tx(&tx_xsk);
> > > -
> > >     /* Make sure freplace correctly picks up original bound device
> > >      * and doesn't crash.
> > >      */
> > > @@ -384,10 +334,11 @@ void test_xdp_metadata(void)
> > >             goto out;
> > >
> > >     /* Send packet to trigger . */
> > > -   if (!ASSERT_GE(generate_packet(&tx_xsk, AF_XDP_CONSUMER_PORT), 0,
> > > -                  "generate freplace packet"))
> > > +   set_netns(tx_netns);
> > > +   if (!ASSERT_GE(generate_packet_udp(), 0, "generate freplace packet"))
> > >             goto out;
> > >
> > > +   set_netns(rx_netns);
> > >     while (!retries--) {
> > >             if (bpf_obj2->bss->called)
> > >                     break;
> > > @@ -397,10 +348,14 @@ void test_xdp_metadata(void)
> > >
> > >  out:
> > >     close_xsk(&rx_xsk);
> > > -   close_xsk(&tx_xsk);
> > >     xdp_metadata2__destroy(bpf_obj2);
> > >     xdp_metadata__destroy(bpf_obj);
> > > -   if (tok)
> > > -           close_netns(tok);
> > > -   SYS_NOFAIL("ip netns del xdp_metadata");
> > > +   set_netns(prev_netns);
> > > +close_ns:
> > > +   close(prev_netns);
> > > +   close(tx_netns);
> > > +   close(rx_netns);
> > > +
> > > +   SYS_NOFAIL("ip netns del " RX_NETNS_NAME);
> > > +   SYS_NOFAIL("ip netns del " TX_NETNS_NAME);
> > >  }
> > > --
> > > 2.41.0
> > >
Stanislav Fomichev July 6, 2023, 5:27 p.m. UTC | #4
On Thu, Jul 6, 2023 at 7:15 AM Larysa Zaremba <larysa.zaremba@intel.com> wrote:
>
> On Wed, Jul 05, 2023 at 10:39:35AM -0700, Stanislav Fomichev wrote:
> > On 07/03, Larysa Zaremba wrote:
> > > The easiest way to simulate stripped VLAN tag in veth is to send a packet
> > > from VLAN interface, attached to veth. Unfortunately, this approach is
> > > incompatible with AF_XDP on TX side, because VLAN interfaces do not have
> > > such feature.
> > >
> > > Replace AF_XDP packet generation with sending the same datagram via
> > > AF_INET socket.
> > >
> > > This does not change the packet contents or hints values with one notable
> > > exception: rx_hash_type, which previously was expected to be 0, now is
> > > expected be at least XDP_RSS_TYPE_L4.
> > >
> > > Also, usage of AF_INET requires a little more complicated namespace setup,
> > > therefore open_netns() helper function is divided into smaller reusable
> > > pieces.
> >
> > Ack, it's probably OK for now, but, FYI, I'm trying to extend this part
> > with TX metadata:
> > https://lore.kernel.org/bpf/20230621170244.1283336-10-sdf@google.com/
> >
> > So probably long-term I'll switch it back to AF_XDP but will add
> > support for requesting vlan TX "offload" from the veth.
> >
>
> My bad for not reading your series. Amazing work as always!
>
> So, 'requesting vlan TX "offload"' with new hints capabilities? This would be
> pretty neat.
>
> But you think AF_INET TX is worth keeping for now, until TX hints are mature?
>
> > > Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
> > > ---
> > >  tools/testing/selftests/bpf/network_helpers.c |  37 +++-
> > >  tools/testing/selftests/bpf/network_helpers.h |   3 +
> > >  .../selftests/bpf/prog_tests/xdp_metadata.c   | 175 +++++++-----------
> > >  3 files changed, 98 insertions(+), 117 deletions(-)
> > >
> > > diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c
> > > index a105c0cd008a..19463230ece5 100644
> > > --- a/tools/testing/selftests/bpf/network_helpers.c
> > > +++ b/tools/testing/selftests/bpf/network_helpers.c
> > > @@ -386,28 +386,51 @@ char *ping_command(int family)
> > >     return "ping";
> > >  }
> > >
> > > +int get_cur_netns(void)
> > > +{
> > > +   int nsfd;
> > > +
> > > +   nsfd = open("/proc/self/ns/net", O_RDONLY);
> > > +   ASSERT_GE(nsfd, 0, "open /proc/self/ns/net");
> > > +   return nsfd;
> > > +}
> > > +
> > > +int get_netns(const char *name)
> > > +{
> > > +   char nspath[PATH_MAX];
> > > +   int nsfd;
> > > +
> > > +   snprintf(nspath, sizeof(nspath), "%s/%s", "/var/run/netns", name);
> > > +   nsfd = open(nspath, O_RDONLY | O_CLOEXEC);
> > > +   ASSERT_GE(nsfd, 0, "open /proc/self/ns/net");
> > > +   return nsfd;
> > > +}
> > > +
> > > +int set_netns(int netns_fd)
> > > +{
> > > +   return setns(netns_fd, CLONE_NEWNET);
> > > +}
> >
> > We have open_netns/close_netns in network_helpers.h that provide similar
> > functionality, let's use them instead?
> >
>
> I have divided open_netns() into smaller pieces (see below), because the code I
> have added into xdp_metadata looked better with those smaller pieces (I had to
> switch namespace several times).

Forgot to reply to this part. I missed the fact that you're extending
network_helpers, sorry.
But why do we need extra namespaces at all?
Larysa Zaremba July 7, 2023, 8:33 a.m. UTC | #5
On Thu, Jul 06, 2023 at 10:27:38AM -0700, Stanislav Fomichev wrote:
> On Thu, Jul 6, 2023 at 7:15 AM Larysa Zaremba <larysa.zaremba@intel.com> wrote:
> >
> > On Wed, Jul 05, 2023 at 10:39:35AM -0700, Stanislav Fomichev wrote:
> > > On 07/03, Larysa Zaremba wrote:
> > > > The easiest way to simulate stripped VLAN tag in veth is to send a packet
> > > > from VLAN interface, attached to veth. Unfortunately, this approach is
> > > > incompatible with AF_XDP on TX side, because VLAN interfaces do not have
> > > > such feature.
> > > >
> > > > Replace AF_XDP packet generation with sending the same datagram via
> > > > AF_INET socket.
> > > >
> > > > This does not change the packet contents or hints values with one notable
> > > > exception: rx_hash_type, which previously was expected to be 0, now is
> > > > expected be at least XDP_RSS_TYPE_L4.
> > > >
> > > > Also, usage of AF_INET requires a little more complicated namespace setup,
> > > > therefore open_netns() helper function is divided into smaller reusable
> > > > pieces.
> > >
> > > Ack, it's probably OK for now, but, FYI, I'm trying to extend this part
> > > with TX metadata:
> > > https://lore.kernel.org/bpf/20230621170244.1283336-10-sdf@google.com/
> > >
> > > So probably long-term I'll switch it back to AF_XDP but will add
> > > support for requesting vlan TX "offload" from the veth.
> > >
> >
> > My bad for not reading your series. Amazing work as always!
> >
> > So, 'requesting vlan TX "offload"' with new hints capabilities? This would be
> > pretty neat.
> >
> > But you think AF_INET TX is worth keeping for now, until TX hints are mature?
> >
> > > > Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
> > > > ---
> > > >  tools/testing/selftests/bpf/network_helpers.c |  37 +++-
> > > >  tools/testing/selftests/bpf/network_helpers.h |   3 +
> > > >  .../selftests/bpf/prog_tests/xdp_metadata.c   | 175 +++++++-----------
> > > >  3 files changed, 98 insertions(+), 117 deletions(-)
> > > >
> > > > diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c
> > > > index a105c0cd008a..19463230ece5 100644
> > > > --- a/tools/testing/selftests/bpf/network_helpers.c
> > > > +++ b/tools/testing/selftests/bpf/network_helpers.c
> > > > @@ -386,28 +386,51 @@ char *ping_command(int family)
> > > >     return "ping";
> > > >  }
> > > >
> > > > +int get_cur_netns(void)
> > > > +{
> > > > +   int nsfd;
> > > > +
> > > > +   nsfd = open("/proc/self/ns/net", O_RDONLY);
> > > > +   ASSERT_GE(nsfd, 0, "open /proc/self/ns/net");
> > > > +   return nsfd;
> > > > +}
> > > > +
> > > > +int get_netns(const char *name)
> > > > +{
> > > > +   char nspath[PATH_MAX];
> > > > +   int nsfd;
> > > > +
> > > > +   snprintf(nspath, sizeof(nspath), "%s/%s", "/var/run/netns", name);
> > > > +   nsfd = open(nspath, O_RDONLY | O_CLOEXEC);
> > > > +   ASSERT_GE(nsfd, 0, "open /proc/self/ns/net");
> > > > +   return nsfd;
> > > > +}
> > > > +
> > > > +int set_netns(int netns_fd)
> > > > +{
> > > > +   return setns(netns_fd, CLONE_NEWNET);
> > > > +}
> > >
> > > We have open_netns/close_netns in network_helpers.h that provide similar
> > > functionality, let's use them instead?
> > >
> >
> > I have divided open_netns() into smaller pieces (see below), because the code I
> > have added into xdp_metadata looked better with those smaller pieces (I had to
> > switch namespace several times).
> 
> Forgot to reply to this part. I missed the fact that you're extending
> network_helpers, sorry.
> But why do we need extra namespaces at all?

If veths are in the same namespace, AF_INET packets are not sent between them,
so XDP is skipped. So we need 2 test namespaces: for RX and TX.
Stanislav Fomichev July 7, 2023, 4:49 p.m. UTC | #6
On 07/07, Larysa Zaremba wrote:
> On Thu, Jul 06, 2023 at 10:27:38AM -0700, Stanislav Fomichev wrote:
> > On Thu, Jul 6, 2023 at 7:15 AM Larysa Zaremba <larysa.zaremba@intel.com> wrote:
> > >
> > > On Wed, Jul 05, 2023 at 10:39:35AM -0700, Stanislav Fomichev wrote:
> > > > On 07/03, Larysa Zaremba wrote:
> > > > > The easiest way to simulate stripped VLAN tag in veth is to send a packet
> > > > > from VLAN interface, attached to veth. Unfortunately, this approach is
> > > > > incompatible with AF_XDP on TX side, because VLAN interfaces do not have
> > > > > such feature.
> > > > >
> > > > > Replace AF_XDP packet generation with sending the same datagram via
> > > > > AF_INET socket.
> > > > >
> > > > > This does not change the packet contents or hints values with one notable
> > > > > exception: rx_hash_type, which previously was expected to be 0, now is
> > > > > expected be at least XDP_RSS_TYPE_L4.
> > > > >
> > > > > Also, usage of AF_INET requires a little more complicated namespace setup,
> > > > > therefore open_netns() helper function is divided into smaller reusable
> > > > > pieces.
> > > >
> > > > Ack, it's probably OK for now, but, FYI, I'm trying to extend this part
> > > > with TX metadata:
> > > > https://lore.kernel.org/bpf/20230621170244.1283336-10-sdf@google.com/
> > > >
> > > > So probably long-term I'll switch it back to AF_XDP but will add
> > > > support for requesting vlan TX "offload" from the veth.
> > > >
> > >
> > > My bad for not reading your series. Amazing work as always!
> > >
> > > So, 'requesting vlan TX "offload"' with new hints capabilities? This would be
> > > pretty neat.
> > >
> > > But you think AF_INET TX is worth keeping for now, until TX hints are mature?
> > >
> > > > > Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
> > > > > ---
> > > > >  tools/testing/selftests/bpf/network_helpers.c |  37 +++-
> > > > >  tools/testing/selftests/bpf/network_helpers.h |   3 +
> > > > >  .../selftests/bpf/prog_tests/xdp_metadata.c   | 175 +++++++-----------
> > > > >  3 files changed, 98 insertions(+), 117 deletions(-)
> > > > >
> > > > > diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c
> > > > > index a105c0cd008a..19463230ece5 100644
> > > > > --- a/tools/testing/selftests/bpf/network_helpers.c
> > > > > +++ b/tools/testing/selftests/bpf/network_helpers.c
> > > > > @@ -386,28 +386,51 @@ char *ping_command(int family)
> > > > >     return "ping";
> > > > >  }
> > > > >
> > > > > +int get_cur_netns(void)
> > > > > +{
> > > > > +   int nsfd;
> > > > > +
> > > > > +   nsfd = open("/proc/self/ns/net", O_RDONLY);
> > > > > +   ASSERT_GE(nsfd, 0, "open /proc/self/ns/net");
> > > > > +   return nsfd;
> > > > > +}
> > > > > +
> > > > > +int get_netns(const char *name)
> > > > > +{
> > > > > +   char nspath[PATH_MAX];
> > > > > +   int nsfd;
> > > > > +
> > > > > +   snprintf(nspath, sizeof(nspath), "%s/%s", "/var/run/netns", name);
> > > > > +   nsfd = open(nspath, O_RDONLY | O_CLOEXEC);
> > > > > +   ASSERT_GE(nsfd, 0, "open /proc/self/ns/net");
> > > > > +   return nsfd;
> > > > > +}
> > > > > +
> > > > > +int set_netns(int netns_fd)
> > > > > +{
> > > > > +   return setns(netns_fd, CLONE_NEWNET);
> > > > > +}
> > > >
> > > > We have open_netns/close_netns in network_helpers.h that provide similar
> > > > functionality, let's use them instead?
> > > >
> > >
> > > I have divided open_netns() into smaller pieces (see below), because the code I
> > > have added into xdp_metadata looked better with those smaller pieces (I had to
> > > switch namespace several times).
> > 
> > Forgot to reply to this part. I missed the fact that you're extending
> > network_helpers, sorry.
> > But why do we need extra namespaces at all?
> 
> If veths are in the same namespace, AF_INET packets are not sent between them,
> so XDP is skipped. So we need 2 test namespaces: for RX and TX.

Makes sense. But let's maybe use the existing helpers to jump to/from
namespaces?

It might be a bit more verbose, but it makes it easy to annotate namespace
being/end. (compared to random jumping around with setns)

tok = open_netns("tx");
do_something();
close_netns(tok);

tok = open_netns("rx");
do_something_else();
close_netns(tok);

Should be doable?
Larysa Zaremba July 7, 2023, 4:58 p.m. UTC | #7
On Fri, Jul 07, 2023 at 09:49:51AM -0700, Stanislav Fomichev wrote:
> On 07/07, Larysa Zaremba wrote:
> > On Thu, Jul 06, 2023 at 10:27:38AM -0700, Stanislav Fomichev wrote:
> > > On Thu, Jul 6, 2023 at 7:15 AM Larysa Zaremba <larysa.zaremba@intel.com> wrote:
> > > >
> > > > On Wed, Jul 05, 2023 at 10:39:35AM -0700, Stanislav Fomichev wrote:
> > > > > On 07/03, Larysa Zaremba wrote:
> > > > > > The easiest way to simulate stripped VLAN tag in veth is to send a packet
> > > > > > from VLAN interface, attached to veth. Unfortunately, this approach is
> > > > > > incompatible with AF_XDP on TX side, because VLAN interfaces do not have
> > > > > > such feature.
> > > > > >
> > > > > > Replace AF_XDP packet generation with sending the same datagram via
> > > > > > AF_INET socket.
> > > > > >
> > > > > > This does not change the packet contents or hints values with one notable
> > > > > > exception: rx_hash_type, which previously was expected to be 0, now is
> > > > > > expected be at least XDP_RSS_TYPE_L4.
> > > > > >
> > > > > > Also, usage of AF_INET requires a little more complicated namespace setup,
> > > > > > therefore open_netns() helper function is divided into smaller reusable
> > > > > > pieces.
> > > > >
> > > > > Ack, it's probably OK for now, but, FYI, I'm trying to extend this part
> > > > > with TX metadata:
> > > > > https://lore.kernel.org/bpf/20230621170244.1283336-10-sdf@google.com/
> > > > >
> > > > > So probably long-term I'll switch it back to AF_XDP but will add
> > > > > support for requesting vlan TX "offload" from the veth.
> > > > >
> > > >
> > > > My bad for not reading your series. Amazing work as always!
> > > >
> > > > So, 'requesting vlan TX "offload"' with new hints capabilities? This would be
> > > > pretty neat.
> > > >
> > > > But you think AF_INET TX is worth keeping for now, until TX hints are mature?
> > > >
> > > > > > Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
> > > > > > ---
> > > > > >  tools/testing/selftests/bpf/network_helpers.c |  37 +++-
> > > > > >  tools/testing/selftests/bpf/network_helpers.h |   3 +
> > > > > >  .../selftests/bpf/prog_tests/xdp_metadata.c   | 175 +++++++-----------
> > > > > >  3 files changed, 98 insertions(+), 117 deletions(-)
> > > > > >
> > > > > > diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c
> > > > > > index a105c0cd008a..19463230ece5 100644
> > > > > > --- a/tools/testing/selftests/bpf/network_helpers.c
> > > > > > +++ b/tools/testing/selftests/bpf/network_helpers.c
> > > > > > @@ -386,28 +386,51 @@ char *ping_command(int family)
> > > > > >     return "ping";
> > > > > >  }
> > > > > >
> > > > > > +int get_cur_netns(void)
> > > > > > +{
> > > > > > +   int nsfd;
> > > > > > +
> > > > > > +   nsfd = open("/proc/self/ns/net", O_RDONLY);
> > > > > > +   ASSERT_GE(nsfd, 0, "open /proc/self/ns/net");
> > > > > > +   return nsfd;
> > > > > > +}
> > > > > > +
> > > > > > +int get_netns(const char *name)
> > > > > > +{
> > > > > > +   char nspath[PATH_MAX];
> > > > > > +   int nsfd;
> > > > > > +
> > > > > > +   snprintf(nspath, sizeof(nspath), "%s/%s", "/var/run/netns", name);
> > > > > > +   nsfd = open(nspath, O_RDONLY | O_CLOEXEC);
> > > > > > +   ASSERT_GE(nsfd, 0, "open /proc/self/ns/net");
> > > > > > +   return nsfd;
> > > > > > +}
> > > > > > +
> > > > > > +int set_netns(int netns_fd)
> > > > > > +{
> > > > > > +   return setns(netns_fd, CLONE_NEWNET);
> > > > > > +}
> > > > >
> > > > > We have open_netns/close_netns in network_helpers.h that provide similar
> > > > > functionality, let's use them instead?
> > > > >
> > > >
> > > > I have divided open_netns() into smaller pieces (see below), because the code I
> > > > have added into xdp_metadata looked better with those smaller pieces (I had to
> > > > switch namespace several times).
> > > 
> > > Forgot to reply to this part. I missed the fact that you're extending
> > > network_helpers, sorry.
> > > But why do we need extra namespaces at all?
> > 
> > If veths are in the same namespace, AF_INET packets are not sent between them,
> > so XDP is skipped. So we need 2 test namespaces: for RX and TX.
> 
> Makes sense. But let's maybe use the existing helpers to jump to/from
> namespaces?
> 
> It might be a bit more verbose, but it makes it easy to annotate namespace
> being/end. (compared to random jumping around with setns)
> 
> tok = open_netns("tx");
> do_something();
> close_netns(tok);
> 
> tok = open_netns("rx");
> do_something_else();
> close_netns(tok);
> 
> Should be doable?

I guess you are right, will rewrite this part to use open_netns()/close_netns(), 
especially considering I have messed up namespace FD management according to CI.
diff mbox series

Patch

diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c
index a105c0cd008a..19463230ece5 100644
--- a/tools/testing/selftests/bpf/network_helpers.c
+++ b/tools/testing/selftests/bpf/network_helpers.c
@@ -386,28 +386,51 @@  char *ping_command(int family)
 	return "ping";
 }
 
+int get_cur_netns(void)
+{
+	int nsfd;
+
+	nsfd = open("/proc/self/ns/net", O_RDONLY);
+	ASSERT_GE(nsfd, 0, "open /proc/self/ns/net");
+	return nsfd;
+}
+
+int get_netns(const char *name)
+{
+	char nspath[PATH_MAX];
+	int nsfd;
+
+	snprintf(nspath, sizeof(nspath), "%s/%s", "/var/run/netns", name);
+	nsfd = open(nspath, O_RDONLY | O_CLOEXEC);
+	ASSERT_GE(nsfd, 0, "open /proc/self/ns/net");
+	return nsfd;
+}
+
+int set_netns(int netns_fd)
+{
+	return setns(netns_fd, CLONE_NEWNET);
+}
+
 struct nstoken {
 	int orig_netns_fd;
 };
 
 struct nstoken *open_netns(const char *name)
 {
+	struct nstoken *token;
 	int nsfd;
-	char nspath[PATH_MAX];
 	int err;
-	struct nstoken *token;
 
 	token = calloc(1, sizeof(struct nstoken));
 	if (!ASSERT_OK_PTR(token, "malloc token"))
 		return NULL;
 
-	token->orig_netns_fd = open("/proc/self/ns/net", O_RDONLY);
-	if (!ASSERT_GE(token->orig_netns_fd, 0, "open /proc/self/ns/net"))
+	token->orig_netns_fd = get_cur_netns();
+	if (token->orig_netns_fd < 0)
 		goto fail;
 
-	snprintf(nspath, sizeof(nspath), "%s/%s", "/var/run/netns", name);
-	nsfd = open(nspath, O_RDONLY | O_CLOEXEC);
-	if (!ASSERT_GE(nsfd, 0, "open netns fd"))
+	nsfd = get_netns(name);
+	if (nsfd < 0)
 		goto fail;
 
 	err = setns(nsfd, CLONE_NEWNET);
diff --git a/tools/testing/selftests/bpf/network_helpers.h b/tools/testing/selftests/bpf/network_helpers.h
index 694185644da6..b18b9619595c 100644
--- a/tools/testing/selftests/bpf/network_helpers.h
+++ b/tools/testing/selftests/bpf/network_helpers.h
@@ -58,6 +58,8 @@  int make_sockaddr(int family, const char *addr_str, __u16 port,
 char *ping_command(int family);
 int get_socket_local_port(int sock_fd);
 
+int get_cur_netns(void);
+int get_netns(const char *name);
 struct nstoken;
 /**
  * open_netns() - Switch to specified network namespace by name.
@@ -67,4 +69,5 @@  struct nstoken;
  */
 struct nstoken *open_netns(const char *name);
 void close_netns(struct nstoken *token);
+int set_netns(int netns_fd);
 #endif
diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
index 626c461fa34d..53b32a641e8e 100644
--- a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
@@ -20,7 +20,7 @@ 
 
 #define UDP_PAYLOAD_BYTES 4
 
-#define AF_XDP_SOURCE_PORT 1234
+#define UDP_SOURCE_PORT 1234
 #define AF_XDP_CONSUMER_PORT 8080
 
 #define UMEM_NUM 16
@@ -33,6 +33,12 @@ 
 #define RX_ADDR "10.0.0.2"
 #define PREFIX_LEN "8"
 #define FAMILY AF_INET
+#define TX_NETNS_NAME "xdp_metadata_tx"
+#define RX_NETNS_NAME "xdp_metadata_rx"
+#define TX_MAC "00:00:00:00:00:01"
+#define RX_MAC "00:00:00:00:00:02"
+
+#define XDP_RSS_TYPE_L4 BIT(3)
 
 struct xsk {
 	void *umem_area;
@@ -119,90 +125,28 @@  static void close_xsk(struct xsk *xsk)
 	munmap(xsk->umem_area, UMEM_SIZE);
 }
 
-static void ip_csum(struct iphdr *iph)
+static int generate_packet_udp(void)
 {
-	__u32 sum = 0;
-	__u16 *p;
-	int i;
-
-	iph->check = 0;
-	p = (void *)iph;
-	for (i = 0; i < sizeof(*iph) / sizeof(*p); i++)
-		sum += p[i];
-
-	while (sum >> 16)
-		sum = (sum & 0xffff) + (sum >> 16);
-
-	iph->check = ~sum;
-}
-
-static int generate_packet(struct xsk *xsk, __u16 dst_port)
-{
-	struct xdp_desc *tx_desc;
-	struct udphdr *udph;
-	struct ethhdr *eth;
-	struct iphdr *iph;
-	void *data;
-	__u32 idx;
-	int ret;
-
-	ret = xsk_ring_prod__reserve(&xsk->tx, 1, &idx);
-	if (!ASSERT_EQ(ret, 1, "xsk_ring_prod__reserve"))
-		return -1;
-
-	tx_desc = xsk_ring_prod__tx_desc(&xsk->tx, idx);
-	tx_desc->addr = idx % (UMEM_NUM / 2) * UMEM_FRAME_SIZE;
-	printf("%p: tx_desc[%u]->addr=%llx\n", xsk, idx, tx_desc->addr);
-	data = xsk_umem__get_data(xsk->umem_area, tx_desc->addr);
-
-	eth = data;
-	iph = (void *)(eth + 1);
-	udph = (void *)(iph + 1);
-
-	memcpy(eth->h_dest, "\x00\x00\x00\x00\x00\x02", ETH_ALEN);
-	memcpy(eth->h_source, "\x00\x00\x00\x00\x00\x01", ETH_ALEN);
-	eth->h_proto = htons(ETH_P_IP);
-
-	iph->version = 0x4;
-	iph->ihl = 0x5;
-	iph->tos = 0x9;
-	iph->tot_len = htons(sizeof(*iph) + sizeof(*udph) + UDP_PAYLOAD_BYTES);
-	iph->id = 0;
-	iph->frag_off = 0;
-	iph->ttl = 0;
-	iph->protocol = IPPROTO_UDP;
-	ASSERT_EQ(inet_pton(FAMILY, TX_ADDR, &iph->saddr), 1, "inet_pton(TX_ADDR)");
-	ASSERT_EQ(inet_pton(FAMILY, RX_ADDR, &iph->daddr), 1, "inet_pton(RX_ADDR)");
-	ip_csum(iph);
-
-	udph->source = htons(AF_XDP_SOURCE_PORT);
-	udph->dest = htons(dst_port);
-	udph->len = htons(sizeof(*udph) + UDP_PAYLOAD_BYTES);
-	udph->check = 0;
-
-	memset(udph + 1, 0xAA, UDP_PAYLOAD_BYTES);
-
-	tx_desc->len = sizeof(*eth) + sizeof(*iph) + sizeof(*udph) + UDP_PAYLOAD_BYTES;
-	xsk_ring_prod__submit(&xsk->tx, 1);
-
-	ret = sendto(xsk_socket__fd(xsk->socket), NULL, 0, MSG_DONTWAIT, NULL, 0);
-	if (!ASSERT_GE(ret, 0, "sendto"))
-		return ret;
-
-	return 0;
-}
-
-static void complete_tx(struct xsk *xsk)
-{
-	__u32 idx;
-	__u64 addr;
-
-	if (ASSERT_EQ(xsk_ring_cons__peek(&xsk->comp, 1, &idx), 1, "xsk_ring_cons__peek")) {
-		addr = *xsk_ring_cons__comp_addr(&xsk->comp, idx);
-
-		printf("%p: complete tx idx=%u addr=%llx\n", xsk, idx, addr);
-		xsk_ring_cons__release(&xsk->comp, 1);
-	}
+	char udp_payload[UDP_PAYLOAD_BYTES];
+	struct sockaddr_in rx_addr;
+	int sock_fd, err = 0;
+
+	/* Build a packet */
+	memset(udp_payload, 0xAA, UDP_PAYLOAD_BYTES);
+	rx_addr.sin_addr.s_addr = inet_addr(RX_ADDR);
+	rx_addr.sin_family = AF_INET;
+	rx_addr.sin_port = htons(UDP_SOURCE_PORT);
+
+	sock_fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
+	if (!ASSERT_GE(sock_fd, 0, "socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)"))
+		return sock_fd;
+
+	err = sendto(sock_fd, udp_payload, UDP_PAYLOAD_BYTES, MSG_DONTWAIT,
+		     (void *)&rx_addr, sizeof(rx_addr));
+	ASSERT_GE(err, 0, "sendto");
+
+	close(sock_fd);
+	return err;
 }
 
 static void refill_rx(struct xsk *xsk, __u64 addr)
@@ -268,7 +212,8 @@  static int verify_xsk_metadata(struct xsk *xsk)
 	if (!ASSERT_NEQ(meta->rx_hash, 0, "rx_hash"))
 		return -1;
 
-	ASSERT_EQ(meta->rx_hash_type, 0, "rx_hash_type");
+	if (!ASSERT_NEQ(meta->rx_hash_type & XDP_RSS_TYPE_L4, 0, "rx_hash_type"))
+		return -1;
 
 	xsk_ring_cons__release(&xsk->rx, 1);
 	refill_rx(xsk, comp_addr);
@@ -281,40 +226,46 @@  void test_xdp_metadata(void)
 	struct xdp_metadata2 *bpf_obj2 = NULL;
 	struct xdp_metadata *bpf_obj = NULL;
 	struct bpf_program *new_prog, *prog;
-	struct nstoken *tok = NULL;
+	int prev_netns, rx_netns, tx_netns;
 	__u32 queue_id = QUEUE_ID;
 	struct bpf_map *prog_arr;
-	struct xsk tx_xsk = {};
 	struct xsk rx_xsk = {};
 	__u32 val, key = 0;
 	int retries = 10;
 	int rx_ifindex;
-	int tx_ifindex;
 	int sock_fd;
 	int ret;
 
-	/* Setup new networking namespace, with a veth pair. */
+	/* Setup new networking namespaces, with a veth pair. */
 
-	SYS(out, "ip netns add xdp_metadata");
-	tok = open_netns("xdp_metadata");
+	SYS(out, "ip netns add " TX_NETNS_NAME);
+	SYS(out, "ip netns add " RX_NETNS_NAME);
+	prev_netns = get_cur_netns();
+	tx_netns = get_netns(TX_NETNS_NAME);
+	rx_netns = get_netns(RX_NETNS_NAME);
+	if (prev_netns < 0 || tx_netns < 0 || rx_netns < 0)
+		goto close_ns;
+
+	set_netns(tx_netns);
 	SYS(out, "ip link add numtxqueues 1 numrxqueues 1 " TX_NAME
 	    " type veth peer " RX_NAME " numtxqueues 1 numrxqueues 1");
-	SYS(out, "ip link set dev " TX_NAME " address 00:00:00:00:00:01");
-	SYS(out, "ip link set dev " RX_NAME " address 00:00:00:00:00:02");
+	SYS(out, "ip link set " RX_NAME " netns " RX_NETNS_NAME);
+
+	SYS(out, "ip link set dev " TX_NAME " address " TX_MAC);
 	SYS(out, "ip link set dev " TX_NAME " up");
-	SYS(out, "ip link set dev " RX_NAME " up");
 	SYS(out, "ip addr add " TX_ADDR "/" PREFIX_LEN " dev " TX_NAME);
-	SYS(out, "ip addr add " RX_ADDR "/" PREFIX_LEN " dev " RX_NAME);
 
+	/* Avoid ARP calls */
+	SYS(out, "ip -4 neigh add " RX_ADDR " lladdr " RX_MAC " dev " TX_NAME);
+
+	set_netns(rx_netns);
+	SYS(out, "ip link set dev " RX_NAME " address " RX_MAC);
+	SYS(out, "ip link set dev " RX_NAME " up");
+	SYS(out, "ip addr add " RX_ADDR "/" PREFIX_LEN " dev " RX_NAME);
 	rx_ifindex = if_nametoindex(RX_NAME);
-	tx_ifindex = if_nametoindex(TX_NAME);
 
 	/* Setup separate AF_XDP for TX and RX interfaces. */
 
-	ret = open_xsk(tx_ifindex, &tx_xsk);
-	if (!ASSERT_OK(ret, "open_xsk(TX_NAME)"))
-		goto out;
-
 	ret = open_xsk(rx_ifindex, &rx_xsk);
 	if (!ASSERT_OK(ret, "open_xsk(RX_NAME)"))
 		goto out;
@@ -355,17 +306,16 @@  void test_xdp_metadata(void)
 		goto out;
 
 	/* Send packet destined to RX AF_XDP socket. */
-	if (!ASSERT_GE(generate_packet(&tx_xsk, AF_XDP_CONSUMER_PORT), 0,
-		       "generate AF_XDP_CONSUMER_PORT"))
+	set_netns(tx_netns);
+	if (!ASSERT_GE(generate_packet_udp(), 0, "generate UDP packet"))
 		goto out;
 
 	/* Verify AF_XDP RX packet has proper metadata. */
+	set_netns(rx_netns);
 	if (!ASSERT_GE(verify_xsk_metadata(&rx_xsk), 0,
 		       "verify_xsk_metadata"))
 		goto out;
 
-	complete_tx(&tx_xsk);
-
 	/* Make sure freplace correctly picks up original bound device
 	 * and doesn't crash.
 	 */
@@ -384,10 +334,11 @@  void test_xdp_metadata(void)
 		goto out;
 
 	/* Send packet to trigger . */
-	if (!ASSERT_GE(generate_packet(&tx_xsk, AF_XDP_CONSUMER_PORT), 0,
-		       "generate freplace packet"))
+	set_netns(tx_netns);
+	if (!ASSERT_GE(generate_packet_udp(), 0, "generate freplace packet"))
 		goto out;
 
+	set_netns(rx_netns);
 	while (!retries--) {
 		if (bpf_obj2->bss->called)
 			break;
@@ -397,10 +348,14 @@  void test_xdp_metadata(void)
 
 out:
 	close_xsk(&rx_xsk);
-	close_xsk(&tx_xsk);
 	xdp_metadata2__destroy(bpf_obj2);
 	xdp_metadata__destroy(bpf_obj);
-	if (tok)
-		close_netns(tok);
-	SYS_NOFAIL("ip netns del xdp_metadata");
+	set_netns(prev_netns);
+close_ns:
+	close(prev_netns);
+	close(tx_netns);
+	close(rx_netns);
+
+	SYS_NOFAIL("ip netns del " RX_NETNS_NAME);
+	SYS_NOFAIL("ip netns del " TX_NETNS_NAME);
 }