diff options
Diffstat (limited to 'support')
| -rw-r--r-- | support/test-container.c | 67 |
1 files changed, 36 insertions, 31 deletions
diff --git a/support/test-container.c b/support/test-container.c index 7557aac441..b6a1158ae1 100644 --- a/support/test-container.c +++ b/support/test-container.c @@ -18,6 +18,7 @@ #define _FILE_OFFSET_BITS 64 +#include <array_length.h> #include <stdio.h> #include <stdlib.h> #include <string.h> @@ -684,39 +685,43 @@ rsync (char *src, char *dest, int and_delete, int force_copies) /* See if we can detect what the user needs to do to get unshare support working for us. */ void -check_for_unshare_hints (void) +check_for_unshare_hints (int require_pidns) { + static struct { + const char *path; + int bad_value, good_value, for_pidns; + } files[] = { + /* Default Debian Linux disables user namespaces, but allows a way + to enable them. */ + { "/proc/sys/kernel/unprivileged_userns_clone", 0, 1, 0 }, + /* ALT Linux has an alternate way of doing the same. */ + { "/proc/sys/kernel/userns_restrict", 1, 0, 0 }, + /* Linux kernel >= 4.9 has a configurable limit on the number of + each namespace. Some distros set the limit to zero to disable the + corresponding namespace as a "security policy". */ + { "/proc/sys/user/max_user_namespaces", 0, 1024, 0 }, + { "/proc/sys/user/max_mnt_namespaces", 0, 1024, 0 }, + { "/proc/sys/user/max_pid_namespaces", 0, 1024, 1 }, + }; FILE *f; - int i; + int i, val; - /* Default Debian Linux disables user namespaces, but allows a way - to enable them. */ - f = fopen ("/proc/sys/kernel/unprivileged_userns_clone", "r"); - if (f != NULL) + for (i = 0; i < array_length (files); i++) { - i = 99; /* Sentinel. */ - fscanf (f, "%d", &i); - if (i == 0) - { - printf ("To enable test-container, please run this as root:\n"); - printf (" echo 1 > /proc/sys/kernel/unprivileged_userns_clone\n"); - } - fclose (f); - return; - } + if (!require_pidns && files[i].for_pidns) + continue; - /* ALT Linux has an alternate way of doing the same. */ - f = fopen ("/proc/sys/kernel/userns_restrict", "r"); - if (f != NULL) - { - i = 99; /* Sentinel. */ - fscanf (f, "%d", &i); - if (i == 1) - { - printf ("To enable test-container, please run this as root:\n"); - printf (" echo 0 > /proc/sys/kernel/userns_restrict\n"); - } - fclose (f); + f = fopen (files[i].path, "r"); + if (f == NULL) + continue; + + val = -1; /* Sentinel. */ + fscanf (f, "%d", &val); + if (val != files[i].bad_value) + continue; + + printf ("To enable test-container, please run this as root:\n"); + printf (" echo %d > %s\n", files[i].good_value, files[i].path); return; } } @@ -1117,11 +1122,11 @@ main (int argc, char **argv) { /* Older kernels may not support all the options, or security policy may block this call. */ - if (errno == EINVAL || errno == EPERM) + if (errno == EINVAL || errno == EPERM || errno == ENOSPC) { int saved_errno = errno; - if (errno == EPERM) - check_for_unshare_hints (); + if (errno == EPERM || errno == ENOSPC) + check_for_unshare_hints (require_pidns); FAIL_UNSUPPORTED ("unable to unshare user/fs: %s", strerror (saved_errno)); } /* We're about to exit anyway, it's "safe" to call unshare again |