diff options
| -rw-r--r-- | configure.ac | 1 | ||||
| -rw-r--r-- | man/NetworkManager.conf.xml | 20 | ||||
| -rw-r--r-- | man/common.ent.in | 1 | ||||
| -rw-r--r-- | src/dns/nm-dns-manager.c | 93 |
4 files changed, 50 insertions, 65 deletions
diff --git a/configure.ac b/configure.ac index b5ca3b4162..611ef582ed 100644 --- a/configure.ac +++ b/configure.ac @@ -89,6 +89,7 @@ AC_SUBST(nmlibdir, '${prefix}'/lib/$PACKAGE, [NetworkManager library directory]) AC_SUBST(nmdatadir, '${datadir}'/$PACKAGE, [NetworkManager shared data directory]) AC_SUBST(nmstatedir, '${localstatedir}'/lib/$PACKAGE, [NetworkManager persistent state directory]) AC_SUBST(nmrundir, '${runstatedir}'/$PACKAGE, [NetworkManager runtime state directory]) +AC_SUBST(nmrundir_, "${runstatedir}/$PACKAGE", [NetworkManager runtime state directory (expanded)]) AC_GNU_SOURCE AC_CHECK_FUNCS([__secure_getenv secure_getenv]) diff --git a/man/NetworkManager.conf.xml b/man/NetworkManager.conf.xml index 8c93ac4c06..7ca496bfb0 100644 --- a/man/NetworkManager.conf.xml +++ b/man/NetworkManager.conf.xml @@ -321,15 +321,17 @@ no-auto-default=* options, and this version of NetworkManager was build with a default of "<literal>&NM_CONFIG_DEFAULT_MAIN_RC_MANAGER;</literal>". Regardless of this setting, NetworkManager will - always write resolv.conf to its runtime state directory.</para> - <para><literal>symlink</literal>: NetworkManager will symlink - <filename>/etc/resolv.conf</filename> to its private - resolv.conf file in the runtime state directory. If - <filename>/etc/resolv.conf</filename> - already is a symlink pointing to a different location, the file - will not be modified. This allows the user to disable managing - by pointing the link <filename>/etc/resolv.conf</filename> to - somewhere else.</para> + always write resolv.conf to its runtime state directory + <filename>&nmrundir;/resolv.conf</filename>.</para> + <para><literal>symlink</literal>: If <filename>/etc/resolv.conf</filename> is + a regular file, NetworkManager will replace the file on update. If + <filename>/etc/resolv.conf</filename> is instead a symlink, NetworkManager + will leave it alone. Unless the symlink points to the internal file + <filename>&nmrundir;/resolv.conf</filename>, + in which case the symlink will be updated to emit an inotify notification. + This allows the user to conveniently instruct NetworkManager not + to manage <filename>/etc/resolv.conf</filename> by replacing it with + a symlink.</para> <para><literal>file</literal>: NetworkManager will write <filename>/etc/resolv.conf</filename> as file. If it finds a symlink, it will follow the symlink and update the target diff --git a/man/common.ent.in b/man/common.ent.in index 4c3310c44b..b3a4bca8fe 100644 --- a/man/common.ent.in +++ b/man/common.ent.in @@ -1,6 +1,7 @@ <?xml version="1.0" encoding="utf-8" ?> <!ENTITY NM_VERSION "@NM_VERSION@"> <!ENTITY sysconfdir "@sysconfdir@"> +<!ENTITY nmrundir "@nmrundir_@"> <!ENTITY NM_CONFIG_DEFAULT_MAIN_AUTH_POLKIT_TEXT "@NM_CONFIG_DEFAULT_MAIN_AUTH_POLKIT_TEXT@"> <!ENTITY NM_CONFIG_DEFAULT_LOGGING_BACKEND_TEXT "@NM_CONFIG_DEFAULT_LOGGING_BACKEND_TEXT@"> <!ENTITY NM_CONFIG_DEFAULT_LOGGING_AUDIT_TEXT "@NM_CONFIG_DEFAULT_LOGGING_AUDIT_TEXT@"> diff --git a/src/dns/nm-dns-manager.c b/src/dns/nm-dns-manager.c index c990243ec7..ab41af9496 100644 --- a/src/dns/nm-dns-manager.c +++ b/src/dns/nm-dns-manager.c @@ -668,6 +668,20 @@ dispatch_resolvconf (NMDnsManager *self, return success ? SR_SUCCESS : SR_ERROR; } +static const char * +_read_link_cached (const char *path, gboolean *is_cached, char **cached) +{ + nm_assert (is_cached); + nm_assert (cached); + + if (*is_cached) + return *cached; + + nm_assert (!*cached); + *is_cached = TRUE; + return (*cached = g_file_read_link (path, NULL)); +} + #define MY_RESOLV_CONF NMRUNDIR "/resolv.conf" #define MY_RESOLV_CONF_TMP MY_RESOLV_CONF ".tmp" #define RESOLV_CONF_TMP "/etc/.resolv.conf.NetworkManager" @@ -681,13 +695,14 @@ update_resolv_conf (NMDnsManager *self, NMDnsManagerResolvConfManager rc_manager) { FILE *f; - struct stat st; gboolean success; gs_free char *content = NULL; SpawnResult write_file_result = SR_SUCCESS; int errsv; const char *rc_path = _PATH_RESCONF; nm_auto_free char *rc_path_real = NULL; + gboolean resconf_link_cached = FALSE; + gs_free char *resconf_link = NULL; /* If we are not managing /etc/resolv.conf and it points to * MY_RESOLV_CONF, don't write the private DNS configuration to @@ -697,9 +712,8 @@ update_resolv_conf (NMDnsManager *self, * This is the only situation, where we don't try to update our * internal resolv.conf file. */ if (rc_manager == NM_DNS_MANAGER_RESOLV_CONF_MAN_UNMANAGED) { - gs_free char *path = g_file_read_link (_PATH_RESCONF, NULL); - - if (g_strcmp0 (path, MY_RESOLV_CONF) == 0) { + if (nm_streq0 (_read_link_cached (_PATH_RESCONF, &resconf_link_cached, &resconf_link), + MY_RESOLV_CONF)) { _LOGD ("update-resolv-conf: not updating " _PATH_RESCONF " since it points to " MY_RESOLV_CONF); return SR_SUCCESS; @@ -708,12 +722,16 @@ update_resolv_conf (NMDnsManager *self, content = create_resolv_conf (searches, nameservers, options); - if (rc_manager == NM_DNS_MANAGER_RESOLV_CONF_MAN_FILE) { + if ( rc_manager == NM_DNS_MANAGER_RESOLV_CONF_MAN_FILE + || ( rc_manager == NM_DNS_MANAGER_RESOLV_CONF_MAN_SYMLINK + && !_read_link_cached (_PATH_RESCONF, &resconf_link_cached, &resconf_link))) { GError *local = NULL; - rc_path_real = realpath (rc_path, NULL); - if (rc_path_real) - rc_path = rc_path_real; + if (rc_manager == NM_DNS_MANAGER_RESOLV_CONF_MAN_FILE) { + rc_path_real = realpath (rc_path, NULL); + if (rc_path_real) + rc_path = rc_path_real; + } /* we first write to /etc/resolv.conf directly. If that fails, * we still continue to write to runstatedir but remember the @@ -788,60 +806,23 @@ update_resolv_conf (NMDnsManager *self, return write_file_result; } - if (rc_manager != NM_DNS_MANAGER_RESOLV_CONF_MAN_SYMLINK) { + if ( rc_manager != NM_DNS_MANAGER_RESOLV_CONF_MAN_SYMLINK + || !_read_link_cached (_PATH_RESCONF, &resconf_link_cached, &resconf_link)) { _LOGT ("update-resolv-conf: write internal file %s succeeded", MY_RESOLV_CONF); return SR_SUCCESS; } - /* A symlink pointing to NM's own resolv.conf (MY_RESOLV_CONF) is always - * overwritten to ensure that changes are indicated with inotify. Symlinks - * pointing to any other file are never overwritten. - */ - if (lstat (_PATH_RESCONF, &st) != 0) { - errsv = errno; - if (errsv != ENOENT) { - /* NM cannot read /etc/resolv.conf */ - _LOGT ("update-resolv-conf: write internal file %s succeeded but lstat(%s) failed (%s)", - MY_RESOLV_CONF, _PATH_RESCONF, g_strerror (errsv)); - g_set_error (error, - NM_MANAGER_ERROR, - NM_MANAGER_ERROR_FAILED, - "Could not lstat %s: %s", - _PATH_RESCONF, - g_strerror (errsv)); - return SR_ERROR; - } - } else { - if (S_ISLNK (st.st_mode)) { - if (stat (_PATH_RESCONF, &st) != -1) { - gs_free char *path = g_file_read_link (_PATH_RESCONF, NULL); - - if (!path || !nm_streq (path, MY_RESOLV_CONF)) { - /* It's not NM's symlink; do nothing */ - _LOGT ("update-resolv-conf: write internal file %s succeeded " - "but don't update %s as it points to %s", - MY_RESOLV_CONF, _PATH_RESCONF, path ?: ""); - return SR_SUCCESS; - } - - /* resolv.conf is a symlink owned by NM and the target is accessible - */ - } else { - /* resolv.conf is a symlink but the target is not accessible; - * some other program is probably managing resolv.conf and - * NM should not touch it. - */ - _LOGT ("update-resolv-conf: write internal file %s succeeded " - "but don't update %s as the symlinks points somewhere else", - MY_RESOLV_CONF, _PATH_RESCONF); - return SR_SUCCESS; - } - } + if (!nm_streq0 (_read_link_cached (_PATH_RESCONF, &resconf_link_cached, &resconf_link), + MY_RESOLV_CONF)) { + _LOGT ("update-resolv-conf: write internal file %s succeeded (don't touch symlink %s linking to %s)", + MY_RESOLV_CONF, _PATH_RESCONF, + _read_link_cached (_PATH_RESCONF, &resconf_link_cached, &resconf_link)); + return SR_SUCCESS; } - /* By this point, either /etc/resolv.conf does not exist, is a regular - * file, or is a symlink already owned by NM. In all cases /etc/resolv.conf - * is replaced with a symlink pointing to NM's resolv.conf in /var/run/. + /* By this point, /etc/resolv.conf exists and is a symlink to our internal + * resolv.conf. We update the symlink so that applications get an inotify + * notification. */ if ( unlink (RESOLV_CONF_TMP) != 0 && ((errsv = errno) != ENOENT)) { |