On Tue, Nov 21, 2023 at 4:15 PM Ahelenia Ziemiańska
<nabijaczleweli@xxxxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxx>
> ---
> v1: <04f3fe71defa757d518468f04f08334a5d0dfbb9.1693754442.git.nabijaczleweli@xxxxxxxxxxxxxxxxxx>
> 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'
