libnetlink: Convert GETMDB dumps to use rtnl_mdbdump_req

[mirror_iproute2.git] / lib / namespace.c

diff --git a/lib/namespace.c b/lib/namespace.c
index 65c1e3d7cd523eeadfac1b702a1320ee1531a2b5..06ae0a48c2243afa4847013a022504dc420a1b45 100644 (file)
--- a/lib/namespace.c
+++ b/lib/namespace.c
@@ -7,20 +7,25 @@
  *             2 of the License, or (at your option) any later version.
  */
 
+#include <sys/statvfs.h>
 #include <fcntl.h>
 #include <dirent.h>
+#include <limits.h>
 
 #include "utils.h"
 #include "namespace.h"
 
 static void bind_etc(const char *name)
 {
-       char etc_netns_path[MAXPATHLEN];
-       char netns_name[MAXPATHLEN];
-       char etc_name[MAXPATHLEN];
+       char etc_netns_path[sizeof(NETNS_ETC_DIR) + NAME_MAX];
+       char netns_name[PATH_MAX];
+       char etc_name[PATH_MAX];
        struct dirent *entry;
        DIR *dir;
 
+       if (strlen(name) >= NAME_MAX)
+               return;
+
        snprintf(etc_netns_path, sizeof(etc_netns_path), "%s/%s", NETNS_ETC_DIR, name);
        dir = opendir(etc_netns_path);
        if (!dir)
@@ -43,8 +48,10 @@ static void bind_etc(const char *name)
 
 int netns_switch(char *name)
 {
-       char net_path[MAXPATHLEN];
+       char net_path[PATH_MAX];
        int netns;
+       unsigned long mountflags = 0;
+       struct statvfs fsstat;
 
        snprintf(net_path, sizeof(net_path), "%s/%s", NETNS_RUN_DIR, name);
        netns = open(net_path, O_RDONLY | O_CLOEXEC);
@@ -57,8 +64,10 @@ int netns_switch(char *name)
        if (setns(netns, CLONE_NEWNET) < 0) {
                fprintf(stderr, "setting the network namespace \"%s\" failed: %s\n",
                        name, strerror(errno));
+               close(netns);
                return -1;
        }
+       close(netns);
 
        if (unshare(CLONE_NEWNS) < 0) {
                fprintf(stderr, "unshare failed: %s\n", strerror(errno));
@@ -70,12 +79,19 @@ int netns_switch(char *name)
                        strerror(errno));
                return -1;
        }
+
        /* Mount a version of /sys that describes the network namespace */
+
        if (umount2("/sys", MNT_DETACH) < 0) {
-               fprintf(stderr, "umount of /sys failed: %s\n", strerror(errno));
-               return -1;
+               /* If this fails, perhaps there wasn't a sysfs instance mounted. Good. */
+               if (statvfs("/sys", &fsstat) == 0) {
+                       /* We couldn't umount the sysfs, we'll attempt to overlay it.
+                        * A read-only instance can't be shadowed with a read-write one. */
+                       if (fsstat.f_flag & ST_RDONLY)
+                               mountflags = MS_RDONLY;
+               }
        }
-       if (mount(name, "/sys", "sysfs", 0, NULL) < 0) {
+       if (mount(name, "/sys", "sysfs", mountflags, NULL) < 0) {
                fprintf(stderr, "mount of /sys failed: %s\n",strerror(errno));
                return -1;
        }
@@ -87,7 +103,7 @@ int netns_switch(char *name)
 
 int netns_get_fd(const char *name)
 {
-       char pathbuf[MAXPATHLEN];
+       char pathbuf[PATH_MAX];
        const char *path, *ptr;
 
        path = name;
@@ -99,3 +115,25 @@ int netns_get_fd(const char *name)
        }
        return open(path, O_RDONLY);
 }
+
+int netns_foreach(int (*func)(char *nsname, void *arg), void *arg)
+{
+       DIR *dir;
+       struct dirent *entry;
+
+       dir = opendir(NETNS_RUN_DIR);
+       if (!dir)
+               return -1;
+
+       while ((entry = readdir(dir)) != NULL) {
+               if (strcmp(entry->d_name, ".") == 0)
+                       continue;
+               if (strcmp(entry->d_name, "..") == 0)
+                       continue;
+               if (func(entry->d_name, arg))
+                       break;
+       }
+
+       closedir(dir);
+       return 0;
+}