[bpf-next,4/6] selftests/bpf: Add setsockopt for network_helper_opts

Commit Message

Geliang Tang April 25, 2024, 3:23 a.m. UTC

From: Geliang Tang <[e-mail]>

__start_server() sets SO_REUSPORT through setsockopt() when the parameter
'reuseport' is set. This patch makes it more flexible by adding setsockopt
function pointer, together with optval and optlen fields into struct
network_helper_opts. Then 'reuseport' parameter can be dropped.

Now the original start_reuseport_server() can be implemented by setting
a newly defined setsockopt_reuseport() function pointer to setsockopt
filed of struct network_helper_opts.

Signed-off-by: Geliang Tang <[e-mail]>
---
 tools/testing/selftests/bpf/network_helpers.c | 26 ++++++++++++-------
 tools/testing/selftests/bpf/network_helpers.h |  3 +++
 2 files changed, 20 insertions(+), 9 deletions(-)

Comments

Martin KaFai Lau May 1, 2024, 12:40 a.m. UTC | #1

On 4/24/24 8:23 PM, Geliang Tang wrote:
> +static int setsockopt_reuseport(int fd, const void *optval, socklen_t optlen)
> +{
> +	return setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, optval, optlen);
>   }
>   

[ ... ]

>   void free_fds(int *fds, unsigned int nr_close_fds)
> diff --git a/tools/testing/selftests/bpf/network_helpers.h b/tools/testing/selftests/bpf/network_helpers.h
> index c62b54daa914..540ecfc52bd7 100644
> --- a/tools/testing/selftests/bpf/network_helpers.h
> +++ b/tools/testing/selftests/bpf/network_helpers.h
> @@ -28,6 +28,9 @@ struct network_helper_opts {
>   	bool noconnect;
>   	int type;
>   	int proto;
> +	int (*setsockopt)(int fd, const void *optval, socklen_t optlen);
> +	const void *optval;
> +	socklen_t optlen;

optval and optlen could be in the stack of the (*setsockopt) callback.
e.g. the "int on;" could be local to the setsockopt_reuseport() instead of 
adding optval/len to the network_helper_opts. Passing one optval in 
network_helper_opts could be less flexible when we want to do multiple 
setsockopt() after socket().

Another nit I would like to make, rename this from (*setsockopt) to 
(*post_socket_cb) because this callback could do more than setsockopt, e.g. 
adding a sk local storage to a socket fd before bind(). Also, add a "const 
struct post_socket_opts *opts" for future extension, Like:

struct post_socket_opts {};

int (*post_socket_cb)(int fd, const struct post_socket_opts *opts);

Patch 6 will need two setsockopt cb functions because of different optval but I 
believe the tradeoff is worth it for this callback doing more than just one 
setsockopt.

Patch 1 to 3 have been applied. Thanks.

Patch

diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c
index 1519f02f8090..baeb4acf5fae 100644
--- a/tools/testing/selftests/bpf/network_helpers.c
+++ b/tools/testing/selftests/bpf/network_helpers.c
@@ -81,9 +81,8 @@  int settimeo(int fd, int timeout_ms)
 #define save_errno_close(fd) ({ int __save = errno; close(fd); errno = __save; })
 
 static int __start_server(int type, const struct sockaddr *addr, socklen_t addrlen,
-			  bool reuseport, const struct network_helper_opts *opts)
+			  const struct network_helper_opts *opts)
 {
-	int on = 1;
 	int fd;
 
 	fd = socket(addr->sa_family, type, opts->proto);
@@ -95,9 +94,9 @@  static int __start_server(int type, const struct sockaddr *addr, socklen_t addrl
 	if (settimeo(fd, opts->timeout_ms))
 		goto error_close;
 
-	if (reuseport &&
-	    setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &on, sizeof(on))) {
-		log_err("Failed to set SO_REUSEPORT");
+	if (opts->setsockopt &&
+	    opts->setsockopt(fd, opts->optval, opts->optlen)) {
+		log_err("Failed to set sockopt");
 		goto error_close;
 	}
 
@@ -132,14 +131,23 @@  int start_server(int family, int type, const char *addr_str, __u16 port,
 	if (make_sockaddr(family, addr_str, port, &addr, &addrlen))
 		return -1;
 
-	return __start_server(type, (struct sockaddr *)&addr, addrlen, false, &opts);
+	return __start_server(type, (struct sockaddr *)&addr, addrlen, &opts);
+}
+
+static int setsockopt_reuseport(int fd, const void *optval, socklen_t optlen)
+{
+	return setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, optval, optlen);
 }
 
 int *start_reuseport_server(int family, int type, const char *addr_str,
 			    __u16 port, int timeout_ms, unsigned int nr_listens)
 {
+	int on = 1;
 	struct network_helper_opts opts = {
 		.timeout_ms = timeout_ms,
+		.setsockopt = setsockopt_reuseport,
+		.optval = &on,
+		.optlen = sizeof(on),
 	};
 	struct sockaddr_storage addr;
 	unsigned int nr_fds = 0;
@@ -156,7 +164,7 @@  int *start_reuseport_server(int family, int type, const char *addr_str,
 	if (!fds)
 		return NULL;
 
-	fds[0] = __start_server(type, (struct sockaddr *)&addr, addrlen, true, &opts);
+	fds[0] = __start_server(type, (struct sockaddr *)&addr, addrlen, &opts);
 	if (fds[0] == -1)
 		goto close_fds;
 	nr_fds = 1;
@@ -165,7 +173,7 @@  int *start_reuseport_server(int family, int type, const char *addr_str,
 		goto close_fds;
 
 	for (; nr_fds < nr_listens; nr_fds++) {
-		fds[nr_fds] = __start_server(type, (struct sockaddr *)&addr, addrlen, true, &opts);
+		fds[nr_fds] = __start_server(type, (struct sockaddr *)&addr, addrlen, &opts);
 		if (fds[nr_fds] == -1)
 			goto close_fds;
 	}
@@ -183,7 +191,7 @@  int start_server_addr(int type, const struct sockaddr_storage *addr, socklen_t l
 	if (!opts)
 		opts = &default_opts;
 
-	return __start_server(type, (struct sockaddr *)addr, len, 0, opts);
+	return __start_server(type, (struct sockaddr *)addr, len, opts);
 }
 
 void free_fds(int *fds, unsigned int nr_close_fds)
diff --git a/tools/testing/selftests/bpf/network_helpers.h b/tools/testing/selftests/bpf/network_helpers.h
index c62b54daa914..540ecfc52bd7 100644
--- a/tools/testing/selftests/bpf/network_helpers.h
+++ b/tools/testing/selftests/bpf/network_helpers.h
@@ -28,6 +28,9 @@  struct network_helper_opts {
 	bool noconnect;
 	int type;
 	int proto;
+	int (*setsockopt)(int fd, const void *optval, socklen_t optlen);
+	const void *optval;
+	socklen_t optlen;
 };
 
 /* ipv4 test vector */