| Message ID | 20221125153453.19323-1-mdoucha@suse.cz |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [1/2] Implement tst_setup_netns() helper function | expand |
Hi Martin, > Namespace setup boilerplate for network tests is getting more complicated > with the need to check or modify some sysfiles. Move it into LTP library. +1 Reviewed-by: Petr Vorel <pvorel@suse.cz> > #define TST_NO_DEFAULT_MAIN > #include "tst_test.h" > #include "tst_net.h" > #include "tst_private.h" > +#include "lapi/namespaces_constants.h" WDYT about adding <sched.h> to lapi/namespaces_constants.h? (not related to this patchset at all). Kind regards, Petr
Hi Martin, > +void tst_setup_netns(void) > +{ > + int real_uid = getuid(); > + int real_gid = getgid(); > + int nscount = 1; > + > + if (!access("/proc/sys/user/max_user_namespaces", F_OK)) { Out of curiosity, this can happen only on old kernel, which does not support user namespaces (kernel < 3.8) ? I guess there must be other case, I suppose you would not bother about 3.8, right? Also asking that if not readable we don't TCONF (int nscount = 1). Kind regards, Petr > + SAFE_FILE_SCANF("/proc/sys/user/max_user_namespaces", "%d", > + &nscount); > + } > + > + if (!nscount) > + tst_brk(TCONF, "User namespaces are disabled"); > + > + SAFE_UNSHARE(CLONE_NEWUSER); > + SAFE_UNSHARE(CLONE_NEWNET); > + SAFE_FILE_PRINTF("/proc/self/setgroups", "deny"); > + SAFE_FILE_PRINTF("/proc/self/uid_map", "0 %d 1", real_uid); > + SAFE_FILE_PRINTF("/proc/self/gid_map", "0 %d 1", real_gid); > +}
On 25. 11. 22 18:01, Petr Vorel wrote: > Hi Martin, > >> +void tst_setup_netns(void) >> +{ >> + int real_uid = getuid(); >> + int real_gid = getgid(); >> + int nscount = 1; >> + >> + if (!access("/proc/sys/user/max_user_namespaces", F_OK)) { > Out of curiosity, this can happen only on old kernel, which does not support > user namespaces (kernel < 3.8) ? I guess there must be other case, > I suppose you would not bother about 3.8, right? > > Also asking that if not readable we don't TCONF (int nscount = 1). This is very much still happening on kernel 4.4.180 even though user namespaces are supported and enabled by default. That's why tst_setup_netns() fails with TCONF only when max_user_namespaces sysfile exists, is read-only AND the value inside is zero.
> On 25. 11. 22 18:01, Petr Vorel wrote: > > Hi Martin, > > > +void tst_setup_netns(void) > > > +{ > > > + int real_uid = getuid(); > > > + int real_gid = getgid(); > > > + int nscount = 1; > > > + > > > + if (!access("/proc/sys/user/max_user_namespaces", F_OK)) { > > Out of curiosity, this can happen only on old kernel, which does not support > > user namespaces (kernel < 3.8) ? I guess there must be other case, > > I suppose you would not bother about 3.8, right? > > Also asking that if not readable we don't TCONF (int nscount = 1). > This is very much still happening on kernel 4.4.180 even though user > namespaces are supported and enabled by default. That's why > tst_setup_netns() fails with TCONF only when max_user_namespaces sysfile > exists, is read-only AND the value inside is zero. Makes sense. And missing file: if I'm correct sysctl files were added in v4.9-rc1 in 25f9c0817c53 ("userns: Generalize the user namespace count into ucount") Kind regards, Petr
Hi Martin, Patchset merged, thanks for this cleanup. Kind regards, Petr
diff --git a/include/tst_net.h b/include/tst_net.h index daefdd9d9..9d8b842dd 100644 --- a/include/tst_net.h +++ b/include/tst_net.h @@ -32,4 +32,20 @@ void safe_getaddrinfo(const char *file, const int lineno, const char *src_addr, const char *port, const struct addrinfo *hints, struct addrinfo **addr_info); +/* + * Create new network namespace for netdevice/socket tests. A test which calls + * tst_setup_netns() must declare the following entries in its struct tst_test: + * + * .needs_kconfigs = (const char *[]) { + * "CONFIG_USER_NS=y", + * "CONFIG_NET_NS=y", + * NULL + * }, + * .save_restore = (const struct tst_path_val[]) { + * {"/proc/sys/user/max_user_namespaces", "1024", TST_SR_SKIP}, + * {} + * }, + */ +void tst_setup_netns(void); + #endif /* TST_NET_H_ */ diff --git a/lib/tst_net.c b/lib/tst_net.c index de343bb39..61fc0ea76 100644 --- a/lib/tst_net.c +++ b/lib/tst_net.c @@ -8,11 +8,13 @@ #include <netdb.h> #include <string.h> #include <stdlib.h> +#include <unistd.h> #define TST_NO_DEFAULT_MAIN #include "tst_test.h" #include "tst_net.h" #include "tst_private.h" +#include "lapi/namespaces_constants.h" void tst_print_svar(const char *name, const char *val) { @@ -220,3 +222,24 @@ void safe_getaddrinfo(const char *file, const int lineno, const char *src_addr, if (!*addr_info) tst_brk_(file, lineno, TBROK, "failed to get the address"); } + +void tst_setup_netns(void) +{ + int real_uid = getuid(); + int real_gid = getgid(); + int nscount = 1; + + if (!access("/proc/sys/user/max_user_namespaces", F_OK)) { + SAFE_FILE_SCANF("/proc/sys/user/max_user_namespaces", "%d", + &nscount); + } + + if (!nscount) + tst_brk(TCONF, "User namespaces are disabled"); + + SAFE_UNSHARE(CLONE_NEWUSER); + SAFE_UNSHARE(CLONE_NEWNET); + SAFE_FILE_PRINTF("/proc/self/setgroups", "deny"); + SAFE_FILE_PRINTF("/proc/self/uid_map", "0 %d 1", real_uid); + SAFE_FILE_PRINTF("/proc/self/gid_map", "0 %d 1", real_gid); +}
Namespace setup boilerplate for network tests is getting more complicated with the need to check or modify some sysfiles. Move it into LTP library. Signed-off-by: Martin Doucha <mdoucha@suse.cz> --- Here is the promised .save_restore follow-up patchset which fixes network namespace setup without root privileges. Since the exact same boilerplate code is repeated in multiple tests, I've decided to introduce a helper function to simplify test setup. include/tst_net.h | 16 ++++++++++++++++ lib/tst_net.c | 23 +++++++++++++++++++++++ 2 files changed, 39 insertions(+)