diff mbox series

[nfs-utils,v2,1/2] fsidd: call anonymous sockets by their name only, don't fill with NULs to 108 bytes

Message ID b38ecca96762d939d377c381bf34521ee5945129.1700601199.git.nabijaczleweli@nabijaczleweli.xyz (mailing list archive)
State New
Headers show
Series [nfs-utils,v2,1/2] fsidd: call anonymous sockets by their name only, don't fill with NULs to 108 bytes | expand

Commit Message

Ahelenia Ziemiańska Nov. 21, 2023, 9:14 p.m. UTC
Since e00ab3c0616fe6d83ab0710d9e7d989c299088f7, ss -l looks like this:
  u_seq               LISTEN                0                     5                                    @/run/fsid.sock@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 26989379                                                       * 0
with fsidd pushing all the addresses to 108 bytes wide, which is deeply
egregious if you don't filter it out and recolumnate.

This is because, naturally (unix(7)), "Null bytes in the name have
no special significance": abstract addresses are binary blobs, but
paths automatically terminate at the first NUL byte, since paths
can't contain those.

So just specify the correct address length when we're using the abstract domain:
unix(7) recommends "offsetof(struct sockaddr_un, sun_path) + strlen(sun_path) + 1"
for paths, but we don't want to include the terminating NUL, so it's just
"offsetof(struct sockaddr_un, sun_path) + strlen(sun_path)".
This brings the width back to order:
-- >8 --
$ ss -la | grep @
u_str ESTAB     0      0      @45208536ec96909a/bus/systemd-timesyn/bus-api-timesync 18500238                            * 18501249
u_str ESTAB     0      0       @fecc9657d2315eb7/bus/systemd-network/bus-api-network 18495452                            * 18494406
u_seq LISTEN    0      5                                             @/run/fsid.sock 27168796                            * 0
u_str ESTAB     0      0                 @ac308f35f50797a2/bus/systemd-logind/system 19406                               * 15153
u_str ESTAB     0      0                @b6606e0dfacbae75/bus/systemd/bus-api-system 18494353                            * 18495334
u_str ESTAB     0      0                    @5880653d215718a7/bus/systemd/bus-system 26930876                            * 26930003
-- >8 --

Fixes: e00ab3c0616fe6d83ab0710d9e7d989c299088f7 ("fsidd: provide
 better default socket name.")
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
---
v1: <04f3fe71defa757d518468f04f08334a5d0dfbb9.1693754442.git.nabijaczleweli@nabijaczleweli.xyz>
v2 NFC, addr_len declared at top of function

 support/reexport/fsidd.c    | 9 ++++++---
 support/reexport/reexport.c | 8 ++++++--
 2 files changed, 12 insertions(+), 5 deletions(-)

Comments

NeilBrown Nov. 21, 2023, 9:17 p.m. UTC | #1
On Wed, 22 Nov 2023, Ahelenia Ziemiańska wrote:
> Since e00ab3c0616fe6d83ab0710d9e7d989c299088f7, ss -l looks like this:
>   u_seq               LISTEN                0                     5                                    @/run/fsid.sock@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 26989379                                                       * 0
> with fsidd pushing all the addresses to 108 bytes wide, which is deeply
> egregious if you don't filter it out and recolumnate.
> 
> This is because, naturally (unix(7)), "Null bytes in the name have
> no special significance": abstract addresses are binary blobs, but
> paths automatically terminate at the first NUL byte, since paths
> can't contain those.
> 
> So just specify the correct address length when we're using the abstract domain:
> unix(7) recommends "offsetof(struct sockaddr_un, sun_path) + strlen(sun_path) + 1"
> for paths, but we don't want to include the terminating NUL, so it's just
> "offsetof(struct sockaddr_un, sun_path) + strlen(sun_path)".
> This brings the width back to order:
> -- >8 --
> $ ss -la | grep @
> u_str ESTAB     0      0      @45208536ec96909a/bus/systemd-timesyn/bus-api-timesync 18500238                            * 18501249
> u_str ESTAB     0      0       @fecc9657d2315eb7/bus/systemd-network/bus-api-network 18495452                            * 18494406
> u_seq LISTEN    0      5                                             @/run/fsid.sock 27168796                            * 0
> u_str ESTAB     0      0                 @ac308f35f50797a2/bus/systemd-logind/system 19406                               * 15153
> u_str ESTAB     0      0                @b6606e0dfacbae75/bus/systemd/bus-api-system 18494353                            * 18495334
> u_str ESTAB     0      0                    @5880653d215718a7/bus/systemd/bus-system 26930876                            * 26930003
> -- >8 --
> 
> Fixes: e00ab3c0616fe6d83ab0710d9e7d989c299088f7 ("fsidd: provide
>  better default socket name.")
> Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
> ---
> v1: <04f3fe71defa757d518468f04f08334a5d0dfbb9.1693754442.git.nabijaczleweli@nabijaczleweli.xyz>
> v2 NFC, addr_len declared at top of function
> 
>  support/reexport/fsidd.c    | 9 ++++++---
>  support/reexport/reexport.c | 8 ++++++--
>  2 files changed, 12 insertions(+), 5 deletions(-)


Reviewed-by: NeilBrown <neilb@suse.de>

Thanks,
NeilBrown


> 
> diff --git a/support/reexport/fsidd.c b/support/reexport/fsidd.c
> index 3e62b3fc..8a70b78f 100644
> --- a/support/reexport/fsidd.c
> +++ b/support/reexport/fsidd.c
> @@ -147,6 +147,7 @@ int main(void)
>  {
>  	struct event *srv_ev;
>  	struct sockaddr_un addr;
> +	socklen_t addr_len;
>  	char *sock_file;
>  	int srv;
>  
> @@ -161,10 +162,12 @@ int main(void)
>  	memset(&addr, 0, sizeof(struct sockaddr_un));
>  	addr.sun_family = AF_UNIX;
>  	strncpy(addr.sun_path, sock_file, sizeof(addr.sun_path) - 1);
> -	if (addr.sun_path[0] == '@')
> +	addr_len = sizeof(struct sockaddr_un);
> +	if (addr.sun_path[0] == '@') {
>  		/* "abstract" socket namespace */
> +		addr_len = offsetof(struct sockaddr_un, sun_path) + strlen(addr.sun_path);
>  		addr.sun_path[0] = 0;
> -	else
> +	} else
>  		unlink(sock_file);
>  
>  	srv = socket(AF_UNIX, SOCK_SEQPACKET | SOCK_NONBLOCK, 0);
> @@ -173,7 +176,7 @@ int main(void)
>  		return 1;
>  	}
>  
> -	if (bind(srv, (const struct sockaddr *)&addr, sizeof(struct sockaddr_un)) == -1) {
> +	if (bind(srv, (const struct sockaddr *)&addr, addr_len) == -1) {
>  		xlog(L_WARNING, "Unable to bind %s: %m\n", sock_file);
>  		return 1;
>  	}
> diff --git a/support/reexport/reexport.c b/support/reexport/reexport.c
> index 78516586..0fb49a46 100644
> --- a/support/reexport/reexport.c
> +++ b/support/reexport/reexport.c
> @@ -21,6 +21,7 @@ static int fsidd_srv = -1;
>  static bool connect_fsid_service(void)
>  {
>  	struct sockaddr_un addr;
> +	socklen_t addr_len;
>  	char *sock_file;
>  	int ret;
>  	int s;
> @@ -33,9 +34,12 @@ static bool connect_fsid_service(void)
>  	memset(&addr, 0, sizeof(struct sockaddr_un));
>  	addr.sun_family = AF_UNIX;
>  	strncpy(addr.sun_path, sock_file, sizeof(addr.sun_path) - 1);
> -	if (addr.sun_path[0] == '@')
> +	addr_len = sizeof(struct sockaddr_un);
> +	if (addr.sun_path[0] == '@') {
>  		/* "abstract" socket namespace */
> +		addr_len = offsetof(struct sockaddr_un, sun_path) + strlen(addr.sun_path);
>  		addr.sun_path[0] = 0;
> +	}
>  
>  	s = socket(AF_UNIX, SOCK_SEQPACKET, 0);
>  	if (s == -1) {
> @@ -43,7 +47,7 @@ static bool connect_fsid_service(void)
>  		return false;
>  	}
>  
> -	ret = connect(s, (const struct sockaddr *)&addr, sizeof(struct sockaddr_un));
> +	ret = connect(s, (const struct sockaddr *)&addr, addr_len);
>  	if (ret == -1) {
>  		xlog(L_WARNING, "Unable to connect %s: %m, is fsidd running?\n", sock_file);
>  		return false;
> -- 
> 2.39.2
> 
>
Steve Dickson Nov. 29, 2023, 12:34 p.m. UTC | #2
On 11/21/23 4:14 PM, Ahelenia Ziemiańska wrote:
> Since e00ab3c0616fe6d83ab0710d9e7d989c299088f7, ss -l looks like this:
>    u_seq               LISTEN                0                     5                                    @/run/fsid.sock@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 26989379                                                       * 0
> with fsidd pushing all the addresses to 108 bytes wide, which is deeply
> egregious if you don't filter it out and recolumnate.
> 
> This is because, naturally (unix(7)), "Null bytes in the name have
> no special significance": abstract addresses are binary blobs, but
> paths automatically terminate at the first NUL byte, since paths
> can't contain those.
> 
> So just specify the correct address length when we're using the abstract domain:
> unix(7) recommends "offsetof(struct sockaddr_un, sun_path) + strlen(sun_path) + 1"
> for paths, but we don't want to include the terminating NUL, so it's just
> "offsetof(struct sockaddr_un, sun_path) + strlen(sun_path)".
> This brings the width back to order:
> -- >8 --
> $ ss -la | grep @
> u_str ESTAB     0      0      @45208536ec96909a/bus/systemd-timesyn/bus-api-timesync 18500238                            * 18501249
> u_str ESTAB     0      0       @fecc9657d2315eb7/bus/systemd-network/bus-api-network 18495452                            * 18494406
> u_seq LISTEN    0      5                                             @/run/fsid.sock 27168796                            * 0
> u_str ESTAB     0      0                 @ac308f35f50797a2/bus/systemd-logind/system 19406                               * 15153
> u_str ESTAB     0      0                @b6606e0dfacbae75/bus/systemd/bus-api-system 18494353                            * 18495334
> u_str ESTAB     0      0                    @5880653d215718a7/bus/systemd/bus-system 26930876                            * 26930003
> -- >8 --
> 
> Fixes: e00ab3c0616fe6d83ab0710d9e7d989c299088f7 ("fsidd: provide
>   better default socket name.")
> Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Committed... (tag: nfs-utils-2-7-1-rc1)

steved
> ---
> v1: <04f3fe71defa757d518468f04f08334a5d0dfbb9.1693754442.git.nabijaczleweli@nabijaczleweli.xyz>
> v2 NFC, addr_len declared at top of function
> 
>   support/reexport/fsidd.c    | 9 ++++++---
>   support/reexport/reexport.c | 8 ++++++--
>   2 files changed, 12 insertions(+), 5 deletions(-)
> 
> diff --git a/support/reexport/fsidd.c b/support/reexport/fsidd.c
> index 3e62b3fc..8a70b78f 100644
> --- a/support/reexport/fsidd.c
> +++ b/support/reexport/fsidd.c
> @@ -147,6 +147,7 @@ int main(void)
>   {
>   	struct event *srv_ev;
>   	struct sockaddr_un addr;
> +	socklen_t addr_len;
>   	char *sock_file;
>   	int srv;
>   
> @@ -161,10 +162,12 @@ int main(void)
>   	memset(&addr, 0, sizeof(struct sockaddr_un));
>   	addr.sun_family = AF_UNIX;
>   	strncpy(addr.sun_path, sock_file, sizeof(addr.sun_path) - 1);
> -	if (addr.sun_path[0] == '@')
> +	addr_len = sizeof(struct sockaddr_un);
> +	if (addr.sun_path[0] == '@') {
>   		/* "abstract" socket namespace */
> +		addr_len = offsetof(struct sockaddr_un, sun_path) + strlen(addr.sun_path);
>   		addr.sun_path[0] = 0;
> -	else
> +	} else
>   		unlink(sock_file);
>   
>   	srv = socket(AF_UNIX, SOCK_SEQPACKET | SOCK_NONBLOCK, 0);
> @@ -173,7 +176,7 @@ int main(void)
>   		return 1;
>   	}
>   
> -	if (bind(srv, (const struct sockaddr *)&addr, sizeof(struct sockaddr_un)) == -1) {
> +	if (bind(srv, (const struct sockaddr *)&addr, addr_len) == -1) {
>   		xlog(L_WARNING, "Unable to bind %s: %m\n", sock_file);
>   		return 1;
>   	}
> diff --git a/support/reexport/reexport.c b/support/reexport/reexport.c
> index 78516586..0fb49a46 100644
> --- a/support/reexport/reexport.c
> +++ b/support/reexport/reexport.c
> @@ -21,6 +21,7 @@ static int fsidd_srv = -1;
>   static bool connect_fsid_service(void)
>   {
>   	struct sockaddr_un addr;
> +	socklen_t addr_len;
>   	char *sock_file;
>   	int ret;
>   	int s;
> @@ -33,9 +34,12 @@ static bool connect_fsid_service(void)
>   	memset(&addr, 0, sizeof(struct sockaddr_un));
>   	addr.sun_family = AF_UNIX;
>   	strncpy(addr.sun_path, sock_file, sizeof(addr.sun_path) - 1);
> -	if (addr.sun_path[0] == '@')
> +	addr_len = sizeof(struct sockaddr_un);
> +	if (addr.sun_path[0] == '@') {
>   		/* "abstract" socket namespace */
> +		addr_len = offsetof(struct sockaddr_un, sun_path) + strlen(addr.sun_path);
>   		addr.sun_path[0] = 0;
> +	}
>   
>   	s = socket(AF_UNIX, SOCK_SEQPACKET, 0);
>   	if (s == -1) {
> @@ -43,7 +47,7 @@ static bool connect_fsid_service(void)
>   		return false;
>   	}
>   
> -	ret = connect(s, (const struct sockaddr *)&addr, sizeof(struct sockaddr_un));
> +	ret = connect(s, (const struct sockaddr *)&addr, addr_len);
>   	if (ret == -1) {
>   		xlog(L_WARNING, "Unable to connect %s: %m, is fsidd running?\n", sock_file);
>   		return false;
Olga Kornievskaia Dec. 6, 2023, 9:33 p.m. UTC | #3
On Tue, Nov 21, 2023 at 4:15 PM Ahelenia Ziemiańska
<nabijaczleweli@nabijaczleweli.xyz> wrote:
>
> Since e00ab3c0616fe6d83ab0710d9e7d989c299088f7, ss -l looks like this:
>   u_seq               LISTEN                0                     5                                    @/run/fsid.sock@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 26989379                                                       * 0
> with fsidd pushing all the addresses to 108 bytes wide, which is deeply
> egregious if you don't filter it out and recolumnate.
>
> This is because, naturally (unix(7)), "Null bytes in the name have
> no special significance": abstract addresses are binary blobs, but
> paths automatically terminate at the first NUL byte, since paths
> can't contain those.
>
> So just specify the correct address length when we're using the abstract domain:
> unix(7) recommends "offsetof(struct sockaddr_un, sun_path) + strlen(sun_path) + 1"
> for paths, but we don't want to include the terminating NUL, so it's just
> "offsetof(struct sockaddr_un, sun_path) + strlen(sun_path)".
> This brings the width back to order:
> -- >8 --
> $ ss -la | grep @
> u_str ESTAB     0      0      @45208536ec96909a/bus/systemd-timesyn/bus-api-timesync 18500238                            * 18501249
> u_str ESTAB     0      0       @fecc9657d2315eb7/bus/systemd-network/bus-api-network 18495452                            * 18494406
> u_seq LISTEN    0      5                                             @/run/fsid.sock 27168796                            * 0
> u_str ESTAB     0      0                 @ac308f35f50797a2/bus/systemd-logind/system 19406                               * 15153
> u_str ESTAB     0      0                @b6606e0dfacbae75/bus/systemd/bus-api-system 18494353                            * 18495334
> u_str ESTAB     0      0                    @5880653d215718a7/bus/systemd/bus-system 26930876                            * 26930003
> -- >8 --
>
> Fixes: e00ab3c0616fe6d83ab0710d9e7d989c299088f7 ("fsidd: provide
>  better default socket name.")
> Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
> ---
> v1: <04f3fe71defa757d518468f04f08334a5d0dfbb9.1693754442.git.nabijaczleweli@nabijaczleweli.xyz>
> v2 NFC, addr_len declared at top of function
>
>  support/reexport/fsidd.c    | 9 ++++++---
>  support/reexport/reexport.c | 8 ++++++--
>  2 files changed, 12 insertions(+), 5 deletions(-)
>
> diff --git a/support/reexport/fsidd.c b/support/reexport/fsidd.c
> index 3e62b3fc..8a70b78f 100644
> --- a/support/reexport/fsidd.c
> +++ b/support/reexport/fsidd.c
> @@ -147,6 +147,7 @@ int main(void)
>  {
>         struct event *srv_ev;
>         struct sockaddr_un addr;
> +       socklen_t addr_len;
>         char *sock_file;
>         int srv;
>
> @@ -161,10 +162,12 @@ int main(void)
>         memset(&addr, 0, sizeof(struct sockaddr_un));
>         addr.sun_family = AF_UNIX;
>         strncpy(addr.sun_path, sock_file, sizeof(addr.sun_path) - 1);
> -       if (addr.sun_path[0] == '@')
> +       addr_len = sizeof(struct sockaddr_un);
> +       if (addr.sun_path[0] == '@') {
>                 /* "abstract" socket namespace */
> +               addr_len = offsetof(struct sockaddr_un, sun_path) + strlen(addr.sun_path);
>                 addr.sun_path[0] = 0;
> -       else
> +       } else
>                 unlink(sock_file);
>
>         srv = socket(AF_UNIX, SOCK_SEQPACKET | SOCK_NONBLOCK, 0);
> @@ -173,7 +176,7 @@ int main(void)
>                 return 1;
>         }
>
> -       if (bind(srv, (const struct sockaddr *)&addr, sizeof(struct sockaddr_un)) == -1) {
> +       if (bind(srv, (const struct sockaddr *)&addr, addr_len) == -1) {
>                 xlog(L_WARNING, "Unable to bind %s: %m\n", sock_file);
>                 return 1;
>         }
> diff --git a/support/reexport/reexport.c b/support/reexport/reexport.c
> index 78516586..0fb49a46 100644
> --- a/support/reexport/reexport.c
> +++ b/support/reexport/reexport.c
> @@ -21,6 +21,7 @@ static int fsidd_srv = -1;
>  static bool connect_fsid_service(void)
>  {
>         struct sockaddr_un addr;
> +       socklen_t addr_len;
>         char *sock_file;
>         int ret;
>         int s;
> @@ -33,9 +34,12 @@ static bool connect_fsid_service(void)
>         memset(&addr, 0, sizeof(struct sockaddr_un));
>         addr.sun_family = AF_UNIX;
>         strncpy(addr.sun_path, sock_file, sizeof(addr.sun_path) - 1);
> -       if (addr.sun_path[0] == '@')
> +       addr_len = sizeof(struct sockaddr_un);
> +       if (addr.sun_path[0] == '@') {
>                 /* "abstract" socket namespace */
> +               addr_len = offsetof(struct sockaddr_un, sun_path) + strlen(addr.sun_path);
>                 addr.sun_path[0] = 0;
> +       }
>
>         s = socket(AF_UNIX, SOCK_SEQPACKET, 0);
>         if (s == -1) {
> @@ -43,7 +47,7 @@ static bool connect_fsid_service(void)
>                 return false;
>         }
>
> -       ret = connect(s, (const struct sockaddr *)&addr, sizeof(struct sockaddr_un));
> +       ret = connect(s, (const struct sockaddr *)&addr, addr_len);
>         if (ret == -1) {
>                 xlog(L_WARNING, "Unable to connect %s: %m, is fsidd running?\n", sock_file);
>                 return false;
> --
> 2.39.2
>

Hi folks,

I'm hitting the following compile error (in RHEL9.2). I believe the
code is missing an include for stddef.h. When I add it, things
compile. I'll submit a patch.

gcc -DHAVE_CONFIG_H -I. -I../../support/include  -I/usr/include/tirpc
-D_GNU_SOURCE -pipe  -Wall  -Wextra  -Werror=strict-prototypes
-Werror=missing-prototypes  -Werror=missing-declarations
-Werror=format=2  -Werror=undef  -Werror=missing-include-dirs
-Werror=strict-aliasing=2  -Werror=init-self
-Werror=implicit-function-declaration  -Werror=return-type
-Werror=switch  -Werror=overflow  -Werror=parentheses
-Werror=aggregate-return  -Werror=unused-result  -fno-strict-aliasing
-Werror=format-overflow=2 -Werror=int-conversion
-Werror=incompatible-pointer-types -Werror=misleading-indentation
-Wno-cast-function-type -g -O2 -MT reexport.o -MD -MP -MF
.deps/reexport.Tpo -c -o reexport.o reexport.c
reexport.c: In function ‘connect_fsid_service’:
reexport.c:40:28: error: implicit declaration of function ‘offsetof’
[-Werror=implicit-function-declaration]
   40 |                 addr_len = offsetof(struct sockaddr_un,
sun_path) + strlen(addr.sun_path);
      |                            ^~~~~~~~
reexport.c:18:1: note: ‘offsetof’ is defined in header ‘<stddef.h>’;
did you forget to ‘#include <stddef.h>’?
   17 | #include "xlog.h"
  +++ |+#include <stddef.h>
   18 |
reexport.c:40:37: error: expected expression before ‘struct’
   40 |                 addr_len = offsetof(struct sockaddr_un,
sun_path) + strlen(addr.sun_path);
      |                                     ^~~~~~
cc1: some warnings being treated as errors
make[2]: *** [Makefile:529: reexport.o] Error 1
make[2]: Leaving directory '/home/aglo/nfs-utils/support/reexport'
make[1]: *** [Makefile:448: all-recursive] Error 1
make[1]: Leaving directory '/home/aglo/nfs-utils/support'
NeilBrown Dec. 8, 2023, 12:08 a.m. UTC | #4
On Thu, 07 Dec 2023, Olga Kornievskaia wrote:
> On Tue, Nov 21, 2023 at 4:15 PM Ahelenia Ziemiańska
> <nabijaczleweli@nabijaczleweli.xyz> wrote:
> >
> > Since e00ab3c0616fe6d83ab0710d9e7d989c299088f7, ss -l looks like this:
> >   u_seq               LISTEN                0                     5                                    @/run/fsid.sock@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 26989379                                                       * 0
> > with fsidd pushing all the addresses to 108 bytes wide, which is deeply
> > egregious if you don't filter it out and recolumnate.
> >
> > This is because, naturally (unix(7)), "Null bytes in the name have
> > no special significance": abstract addresses are binary blobs, but
> > paths automatically terminate at the first NUL byte, since paths
> > can't contain those.
> >
> > So just specify the correct address length when we're using the abstract domain:
> > unix(7) recommends "offsetof(struct sockaddr_un, sun_path) + strlen(sun_path) + 1"
> > for paths, but we don't want to include the terminating NUL, so it's just
> > "offsetof(struct sockaddr_un, sun_path) + strlen(sun_path)".
> > This brings the width back to order:
> > -- >8 --
> > $ ss -la | grep @
> > u_str ESTAB     0      0      @45208536ec96909a/bus/systemd-timesyn/bus-api-timesync 18500238                            * 18501249
> > u_str ESTAB     0      0       @fecc9657d2315eb7/bus/systemd-network/bus-api-network 18495452                            * 18494406
> > u_seq LISTEN    0      5                                             @/run/fsid.sock 27168796                            * 0
> > u_str ESTAB     0      0                 @ac308f35f50797a2/bus/systemd-logind/system 19406                               * 15153
> > u_str ESTAB     0      0                @b6606e0dfacbae75/bus/systemd/bus-api-system 18494353                            * 18495334
> > u_str ESTAB     0      0                    @5880653d215718a7/bus/systemd/bus-system 26930876                            * 26930003
> > -- >8 --
> >
> > Fixes: e00ab3c0616fe6d83ab0710d9e7d989c299088f7 ("fsidd: provide
> >  better default socket name.")
> > Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
> > ---
> > v1: <04f3fe71defa757d518468f04f08334a5d0dfbb9.1693754442.git.nabijaczleweli@nabijaczleweli.xyz>
> > v2 NFC, addr_len declared at top of function
> >
> >  support/reexport/fsidd.c    | 9 ++++++---
> >  support/reexport/reexport.c | 8 ++++++--
> >  2 files changed, 12 insertions(+), 5 deletions(-)
> >
> > diff --git a/support/reexport/fsidd.c b/support/reexport/fsidd.c
> > index 3e62b3fc..8a70b78f 100644
> > --- a/support/reexport/fsidd.c
> > +++ b/support/reexport/fsidd.c
> > @@ -147,6 +147,7 @@ int main(void)
> >  {
> >         struct event *srv_ev;
> >         struct sockaddr_un addr;
> > +       socklen_t addr_len;
> >         char *sock_file;
> >         int srv;
> >
> > @@ -161,10 +162,12 @@ int main(void)
> >         memset(&addr, 0, sizeof(struct sockaddr_un));
> >         addr.sun_family = AF_UNIX;
> >         strncpy(addr.sun_path, sock_file, sizeof(addr.sun_path) - 1);
> > -       if (addr.sun_path[0] == '@')
> > +       addr_len = sizeof(struct sockaddr_un);
> > +       if (addr.sun_path[0] == '@') {
> >                 /* "abstract" socket namespace */
> > +               addr_len = offsetof(struct sockaddr_un, sun_path) + strlen(addr.sun_path);
> >                 addr.sun_path[0] = 0;
> > -       else
> > +       } else
> >                 unlink(sock_file);
> >
> >         srv = socket(AF_UNIX, SOCK_SEQPACKET | SOCK_NONBLOCK, 0);
> > @@ -173,7 +176,7 @@ int main(void)
> >                 return 1;
> >         }
> >
> > -       if (bind(srv, (const struct sockaddr *)&addr, sizeof(struct sockaddr_un)) == -1) {
> > +       if (bind(srv, (const struct sockaddr *)&addr, addr_len) == -1) {
> >                 xlog(L_WARNING, "Unable to bind %s: %m\n", sock_file);
> >                 return 1;
> >         }
> > diff --git a/support/reexport/reexport.c b/support/reexport/reexport.c
> > index 78516586..0fb49a46 100644
> > --- a/support/reexport/reexport.c
> > +++ b/support/reexport/reexport.c
> > @@ -21,6 +21,7 @@ static int fsidd_srv = -1;
> >  static bool connect_fsid_service(void)
> >  {
> >         struct sockaddr_un addr;
> > +       socklen_t addr_len;
> >         char *sock_file;
> >         int ret;
> >         int s;
> > @@ -33,9 +34,12 @@ static bool connect_fsid_service(void)
> >         memset(&addr, 0, sizeof(struct sockaddr_un));
> >         addr.sun_family = AF_UNIX;
> >         strncpy(addr.sun_path, sock_file, sizeof(addr.sun_path) - 1);
> > -       if (addr.sun_path[0] == '@')
> > +       addr_len = sizeof(struct sockaddr_un);
> > +       if (addr.sun_path[0] == '@') {
> >                 /* "abstract" socket namespace */
> > +               addr_len = offsetof(struct sockaddr_un, sun_path) + strlen(addr.sun_path);
> >                 addr.sun_path[0] = 0;
> > +       }
> >
> >         s = socket(AF_UNIX, SOCK_SEQPACKET, 0);
> >         if (s == -1) {
> > @@ -43,7 +47,7 @@ static bool connect_fsid_service(void)
> >                 return false;
> >         }
> >
> > -       ret = connect(s, (const struct sockaddr *)&addr, sizeof(struct sockaddr_un));
> > +       ret = connect(s, (const struct sockaddr *)&addr, addr_len);
> >         if (ret == -1) {
> >                 xlog(L_WARNING, "Unable to connect %s: %m, is fsidd running?\n", sock_file);
> >                 return false;
> > --
> > 2.39.2
> >
> 
> Hi folks,
> 
> I'm hitting the following compile error (in RHEL9.2). I believe the
> code is missing an include for stddef.h. When I add it, things
> compile. I'll submit a patch.
> 
> gcc -DHAVE_CONFIG_H -I. -I../../support/include  -I/usr/include/tirpc
> -D_GNU_SOURCE -pipe  -Wall  -Wextra  -Werror=strict-prototypes
> -Werror=missing-prototypes  -Werror=missing-declarations
> -Werror=format=2  -Werror=undef  -Werror=missing-include-dirs
> -Werror=strict-aliasing=2  -Werror=init-self
> -Werror=implicit-function-declaration  -Werror=return-type
> -Werror=switch  -Werror=overflow  -Werror=parentheses
> -Werror=aggregate-return  -Werror=unused-result  -fno-strict-aliasing
> -Werror=format-overflow=2 -Werror=int-conversion
> -Werror=incompatible-pointer-types -Werror=misleading-indentation
> -Wno-cast-function-type -g -O2 -MT reexport.o -MD -MP -MF
> .deps/reexport.Tpo -c -o reexport.o reexport.c
> reexport.c: In function ‘connect_fsid_service’:
> reexport.c:40:28: error: implicit declaration of function ‘offsetof’
> [-Werror=implicit-function-declaration]
>    40 |                 addr_len = offsetof(struct sockaddr_un,
> sun_path) + strlen(addr.sun_path);
>       |                            ^~~~~~~~
> reexport.c:18:1: note: ‘offsetof’ is defined in header ‘<stddef.h>’;
> did you forget to ‘#include <stddef.h>’?
>    17 | #include "xlog.h"
>   +++ |+#include <stddef.h>
>    18 |
> reexport.c:40:37: error: expected expression before ‘struct’
>    40 |                 addr_len = offsetof(struct sockaddr_un,
> sun_path) + strlen(addr.sun_path);
>       |                                     ^~~~~~
> cc1: some warnings being treated as errors
> make[2]: *** [Makefile:529: reexport.o] Error 1
> make[2]: Leaving directory '/home/aglo/nfs-utils/support/reexport'
> make[1]: *** [Makefile:448: all-recursive] Error 1
> make[1]: Leaving directory '/home/aglo/nfs-utils/support'
> 


Interesting - in openSUSE, dlfcn.h includes stddef.h, which is why the
compile works for me.   Obviously we cannot rely on that.

reexport.c and fsidd.c will both need stddef.

Thanks!

NeilBrown
Olga Kornievskaia Dec. 8, 2023, 6:55 p.m. UTC | #5
On Thu, Dec 7, 2023 at 7:08 PM NeilBrown <neilb@suse.de> wrote:
>
> On Thu, 07 Dec 2023, Olga Kornievskaia wrote:
> > On Tue, Nov 21, 2023 at 4:15 PM Ahelenia Ziemiańska
> > <nabijaczleweli@nabijaczleweli.xyz> wrote:
> > >
> > > Since e00ab3c0616fe6d83ab0710d9e7d989c299088f7, ss -l looks like this:
> > >   u_seq               LISTEN                0                     5                                    @/run/fsid.sock@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 26989379                                                       * 0
> > > with fsidd pushing all the addresses to 108 bytes wide, which is deeply
> > > egregious if you don't filter it out and recolumnate.
> > >
> > > This is because, naturally (unix(7)), "Null bytes in the name have
> > > no special significance": abstract addresses are binary blobs, but
> > > paths automatically terminate at the first NUL byte, since paths
> > > can't contain those.
> > >
> > > So just specify the correct address length when we're using the abstract domain:
> > > unix(7) recommends "offsetof(struct sockaddr_un, sun_path) + strlen(sun_path) + 1"
> > > for paths, but we don't want to include the terminating NUL, so it's just
> > > "offsetof(struct sockaddr_un, sun_path) + strlen(sun_path)".
> > > This brings the width back to order:
> > > -- >8 --
> > > $ ss -la | grep @
> > > u_str ESTAB     0      0      @45208536ec96909a/bus/systemd-timesyn/bus-api-timesync 18500238                            * 18501249
> > > u_str ESTAB     0      0       @fecc9657d2315eb7/bus/systemd-network/bus-api-network 18495452                            * 18494406
> > > u_seq LISTEN    0      5                                             @/run/fsid.sock 27168796                            * 0
> > > u_str ESTAB     0      0                 @ac308f35f50797a2/bus/systemd-logind/system 19406                               * 15153
> > > u_str ESTAB     0      0                @b6606e0dfacbae75/bus/systemd/bus-api-system 18494353                            * 18495334
> > > u_str ESTAB     0      0                    @5880653d215718a7/bus/systemd/bus-system 26930876                            * 26930003
> > > -- >8 --
> > >
> > > Fixes: e00ab3c0616fe6d83ab0710d9e7d989c299088f7 ("fsidd: provide
> > >  better default socket name.")
> > > Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
> > > ---
> > > v1: <04f3fe71defa757d518468f04f08334a5d0dfbb9.1693754442.git.nabijaczleweli@nabijaczleweli.xyz>
> > > v2 NFC, addr_len declared at top of function
> > >
> > >  support/reexport/fsidd.c    | 9 ++++++---
> > >  support/reexport/reexport.c | 8 ++++++--
> > >  2 files changed, 12 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/support/reexport/fsidd.c b/support/reexport/fsidd.c
> > > index 3e62b3fc..8a70b78f 100644
> > > --- a/support/reexport/fsidd.c
> > > +++ b/support/reexport/fsidd.c
> > > @@ -147,6 +147,7 @@ int main(void)
> > >  {
> > >         struct event *srv_ev;
> > >         struct sockaddr_un addr;
> > > +       socklen_t addr_len;
> > >         char *sock_file;
> > >         int srv;
> > >
> > > @@ -161,10 +162,12 @@ int main(void)
> > >         memset(&addr, 0, sizeof(struct sockaddr_un));
> > >         addr.sun_family = AF_UNIX;
> > >         strncpy(addr.sun_path, sock_file, sizeof(addr.sun_path) - 1);
> > > -       if (addr.sun_path[0] == '@')
> > > +       addr_len = sizeof(struct sockaddr_un);
> > > +       if (addr.sun_path[0] == '@') {
> > >                 /* "abstract" socket namespace */
> > > +               addr_len = offsetof(struct sockaddr_un, sun_path) + strlen(addr.sun_path);
> > >                 addr.sun_path[0] = 0;
> > > -       else
> > > +       } else
> > >                 unlink(sock_file);
> > >
> > >         srv = socket(AF_UNIX, SOCK_SEQPACKET | SOCK_NONBLOCK, 0);
> > > @@ -173,7 +176,7 @@ int main(void)
> > >                 return 1;
> > >         }
> > >
> > > -       if (bind(srv, (const struct sockaddr *)&addr, sizeof(struct sockaddr_un)) == -1) {
> > > +       if (bind(srv, (const struct sockaddr *)&addr, addr_len) == -1) {
> > >                 xlog(L_WARNING, "Unable to bind %s: %m\n", sock_file);
> > >                 return 1;
> > >         }
> > > diff --git a/support/reexport/reexport.c b/support/reexport/reexport.c
> > > index 78516586..0fb49a46 100644
> > > --- a/support/reexport/reexport.c
> > > +++ b/support/reexport/reexport.c
> > > @@ -21,6 +21,7 @@ static int fsidd_srv = -1;
> > >  static bool connect_fsid_service(void)
> > >  {
> > >         struct sockaddr_un addr;
> > > +       socklen_t addr_len;
> > >         char *sock_file;
> > >         int ret;
> > >         int s;
> > > @@ -33,9 +34,12 @@ static bool connect_fsid_service(void)
> > >         memset(&addr, 0, sizeof(struct sockaddr_un));
> > >         addr.sun_family = AF_UNIX;
> > >         strncpy(addr.sun_path, sock_file, sizeof(addr.sun_path) - 1);
> > > -       if (addr.sun_path[0] == '@')
> > > +       addr_len = sizeof(struct sockaddr_un);
> > > +       if (addr.sun_path[0] == '@') {
> > >                 /* "abstract" socket namespace */
> > > +               addr_len = offsetof(struct sockaddr_un, sun_path) + strlen(addr.sun_path);
> > >                 addr.sun_path[0] = 0;
> > > +       }
> > >
> > >         s = socket(AF_UNIX, SOCK_SEQPACKET, 0);
> > >         if (s == -1) {
> > > @@ -43,7 +47,7 @@ static bool connect_fsid_service(void)
> > >                 return false;
> > >         }
> > >
> > > -       ret = connect(s, (const struct sockaddr *)&addr, sizeof(struct sockaddr_un));
> > > +       ret = connect(s, (const struct sockaddr *)&addr, addr_len);
> > >         if (ret == -1) {
> > >                 xlog(L_WARNING, "Unable to connect %s: %m, is fsidd running?\n", sock_file);
> > >                 return false;
> > > --
> > > 2.39.2
> > >
> >
> > Hi folks,
> >
> > I'm hitting the following compile error (in RHEL9.2). I believe the
> > code is missing an include for stddef.h. When I add it, things
> > compile. I'll submit a patch.
> >
> > gcc -DHAVE_CONFIG_H -I. -I../../support/include  -I/usr/include/tirpc
> > -D_GNU_SOURCE -pipe  -Wall  -Wextra  -Werror=strict-prototypes
> > -Werror=missing-prototypes  -Werror=missing-declarations
> > -Werror=format=2  -Werror=undef  -Werror=missing-include-dirs
> > -Werror=strict-aliasing=2  -Werror=init-self
> > -Werror=implicit-function-declaration  -Werror=return-type
> > -Werror=switch  -Werror=overflow  -Werror=parentheses
> > -Werror=aggregate-return  -Werror=unused-result  -fno-strict-aliasing
> > -Werror=format-overflow=2 -Werror=int-conversion
> > -Werror=incompatible-pointer-types -Werror=misleading-indentation
> > -Wno-cast-function-type -g -O2 -MT reexport.o -MD -MP -MF
> > .deps/reexport.Tpo -c -o reexport.o reexport.c
> > reexport.c: In function ‘connect_fsid_service’:
> > reexport.c:40:28: error: implicit declaration of function ‘offsetof’
> > [-Werror=implicit-function-declaration]
> >    40 |                 addr_len = offsetof(struct sockaddr_un,
> > sun_path) + strlen(addr.sun_path);
> >       |                            ^~~~~~~~
> > reexport.c:18:1: note: ‘offsetof’ is defined in header ‘<stddef.h>’;
> > did you forget to ‘#include <stddef.h>’?
> >    17 | #include "xlog.h"
> >   +++ |+#include <stddef.h>
> >    18 |
> > reexport.c:40:37: error: expected expression before ‘struct’
> >    40 |                 addr_len = offsetof(struct sockaddr_un,
> > sun_path) + strlen(addr.sun_path);
> >       |                                     ^~~~~~
> > cc1: some warnings being treated as errors
> > make[2]: *** [Makefile:529: reexport.o] Error 1
> > make[2]: Leaving directory '/home/aglo/nfs-utils/support/reexport'
> > make[1]: *** [Makefile:448: all-recursive] Error 1
> > make[1]: Leaving directory '/home/aglo/nfs-utils/support'
> >
>
>
> Interesting - in openSUSE, dlfcn.h includes stddef.h, which is why the
> compile works for me.   Obviously we cannot rely on that.
>
> reexport.c and fsidd.c will both need stddef.

Hm. ok once I added to reexport.c things recompiled for me. so my
patch only covered that.

I can write a v2 of the patch I submitted to include both.

>
> Thanks!
>
> NeilBrown
diff mbox series

Patch

diff --git a/support/reexport/fsidd.c b/support/reexport/fsidd.c
index 3e62b3fc..8a70b78f 100644
--- a/support/reexport/fsidd.c
+++ b/support/reexport/fsidd.c
@@ -147,6 +147,7 @@  int main(void)
 {
 	struct event *srv_ev;
 	struct sockaddr_un addr;
+	socklen_t addr_len;
 	char *sock_file;
 	int srv;
 
@@ -161,10 +162,12 @@  int main(void)
 	memset(&addr, 0, sizeof(struct sockaddr_un));
 	addr.sun_family = AF_UNIX;
 	strncpy(addr.sun_path, sock_file, sizeof(addr.sun_path) - 1);
-	if (addr.sun_path[0] == '@')
+	addr_len = sizeof(struct sockaddr_un);
+	if (addr.sun_path[0] == '@') {
 		/* "abstract" socket namespace */
+		addr_len = offsetof(struct sockaddr_un, sun_path) + strlen(addr.sun_path);
 		addr.sun_path[0] = 0;
-	else
+	} else
 		unlink(sock_file);
 
 	srv = socket(AF_UNIX, SOCK_SEQPACKET | SOCK_NONBLOCK, 0);
@@ -173,7 +176,7 @@  int main(void)
 		return 1;
 	}
 
-	if (bind(srv, (const struct sockaddr *)&addr, sizeof(struct sockaddr_un)) == -1) {
+	if (bind(srv, (const struct sockaddr *)&addr, addr_len) == -1) {
 		xlog(L_WARNING, "Unable to bind %s: %m\n", sock_file);
 		return 1;
 	}
diff --git a/support/reexport/reexport.c b/support/reexport/reexport.c
index 78516586..0fb49a46 100644
--- a/support/reexport/reexport.c
+++ b/support/reexport/reexport.c
@@ -21,6 +21,7 @@  static int fsidd_srv = -1;
 static bool connect_fsid_service(void)
 {
 	struct sockaddr_un addr;
+	socklen_t addr_len;
 	char *sock_file;
 	int ret;
 	int s;
@@ -33,9 +34,12 @@  static bool connect_fsid_service(void)
 	memset(&addr, 0, sizeof(struct sockaddr_un));
 	addr.sun_family = AF_UNIX;
 	strncpy(addr.sun_path, sock_file, sizeof(addr.sun_path) - 1);
-	if (addr.sun_path[0] == '@')
+	addr_len = sizeof(struct sockaddr_un);
+	if (addr.sun_path[0] == '@') {
 		/* "abstract" socket namespace */
+		addr_len = offsetof(struct sockaddr_un, sun_path) + strlen(addr.sun_path);
 		addr.sun_path[0] = 0;
+	}
 
 	s = socket(AF_UNIX, SOCK_SEQPACKET, 0);
 	if (s == -1) {
@@ -43,7 +47,7 @@  static bool connect_fsid_service(void)
 		return false;
 	}
 
-	ret = connect(s, (const struct sockaddr *)&addr, sizeof(struct sockaddr_un));
+	ret = connect(s, (const struct sockaddr *)&addr, addr_len);
 	if (ret == -1) {
 		xlog(L_WARNING, "Unable to connect %s: %m, is fsidd running?\n", sock_file);
 		return false;