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authorLennart Poettering <lennart@poettering.net>2016-05-06 20:58:32 +0200
committerLennart Poettering <lennart@poettering.net>2016-05-09 15:45:31 +0200
commitef76dff225a00008fe0edd1f528c9096f1a91179 (patch)
treee3e56ed2a228d8c265c709fc97a408af6bb1a3e9
parent5e7423ff25b4b9b0a32753b9d1ec82a36e34b290 (diff)
util-lib: add new ifname_valid() call that validates interface names
Make use of this in nspawn at a couple of places. A later commit should port more code over to this, including networkd.
-rw-r--r--src/basic/socket-util.c38
-rw-r--r--src/basic/socket-util.h2
-rw-r--r--src/nspawn/nspawn-network.c6
-rw-r--r--src/nspawn/nspawn.c24
-rw-r--r--src/test/test-socket-util.c25
5 files changed, 93 insertions, 2 deletions
diff --git a/src/basic/socket-util.c b/src/basic/socket-util.c
index c634f1d564..c8769a54f4 100644
--- a/src/basic/socket-util.c
+++ b/src/basic/socket-util.c
@@ -43,7 +43,9 @@
#include "socket-util.h"
#include "string-table.h"
#include "string-util.h"
+#include "strv.h"
#include "user-util.h"
+#include "utf8.h"
#include "util.h"
int socket_address_parse(SocketAddress *a, const char *s) {
@@ -795,6 +797,42 @@ static const char* const ip_tos_table[] = {
DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(ip_tos, int, 0xff);
+bool ifname_valid(const char *p) {
+ bool numeric = true;
+
+ /* Checks whether a network interface name is valid. This is inspired by dev_valid_name() in the kernel sources
+ * but slightly stricter, as we only allow non-control, non-space ASCII characters in the interface name. We
+ * also don't permit names that only container numbers, to avoid confusion with numeric interface indexes. */
+
+ if (isempty(p))
+ return false;
+
+ if (strlen(p) >= IFNAMSIZ)
+ return false;
+
+ if (STR_IN_SET(p, ".", ".."))
+ return false;
+
+ while (*p) {
+ if ((unsigned char) *p >= 127U)
+ return false;
+
+ if ((unsigned char) *p <= 32U)
+ return false;
+
+ if (*p == ':' || *p == '/')
+ return false;
+
+ numeric = numeric && (*p >= '0' && *p <= '9');
+ p++;
+ }
+
+ if (numeric)
+ return false;
+
+ return true;
+}
+
int getpeercred(int fd, struct ucred *ucred) {
socklen_t n = sizeof(struct ucred);
struct ucred u;
diff --git a/src/basic/socket-util.h b/src/basic/socket-util.h
index 160f7c484b..e9230e4a9f 100644
--- a/src/basic/socket-util.h
+++ b/src/basic/socket-util.h
@@ -123,6 +123,8 @@ int fd_inc_rcvbuf(int fd, size_t n);
int ip_tos_to_string_alloc(int i, char **s);
int ip_tos_from_string(const char *s);
+bool ifname_valid(const char *p);
+
int getpeercred(int fd, struct ucred *ucred);
int getpeersec(int fd, char **ret);
diff --git a/src/nspawn/nspawn-network.c b/src/nspawn/nspawn-network.c
index f2b7e4dd79..9938fce503 100644
--- a/src/nspawn/nspawn-network.c
+++ b/src/nspawn/nspawn-network.c
@@ -29,6 +29,8 @@
#include "netlink-util.h"
#include "nspawn-network.h"
#include "siphash24.h"
+#include "socket-util.h"
+#include "stat-util.h"
#include "string-util.h"
#include "udev-util.h"
#include "util.h"
@@ -515,13 +517,13 @@ int veth_extra_parse(char ***l, const char *p) {
r = extract_first_word(&p, &a, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
if (r < 0)
return r;
- if (r == 0 || isempty(a))
+ if (r == 0 || !ifname_valid(a))
return -EINVAL;
r = extract_first_word(&p, &b, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
if (r < 0)
return r;
- if (r == 0 || isempty(b)) {
+ if (r == 0 || !ifname_valid(b)) {
free(b);
b = strdup(a);
if (!b)
diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c
index 3fc6cc955c..643f459851 100644
--- a/src/nspawn/nspawn.c
+++ b/src/nspawn/nspawn.c
@@ -467,6 +467,12 @@ static int parse_argv(int argc, char *argv[]) {
break;
case ARG_NETWORK_BRIDGE:
+
+ if (!ifname_valid(optarg)) {
+ log_error("Bridge interface name not valid: %s", optarg);
+ return -EINVAL;
+ }
+
r = free_and_strdup(&arg_network_bridge, optarg);
if (r < 0)
return log_oom();
@@ -489,6 +495,12 @@ static int parse_argv(int argc, char *argv[]) {
break;
case ARG_NETWORK_INTERFACE:
+
+ if (!ifname_valid(optarg)) {
+ log_error("Network interface name not valid: %s", optarg);
+ return -EINVAL;
+ }
+
if (strv_extend(&arg_network_interfaces, optarg) < 0)
return log_oom();
@@ -497,6 +509,12 @@ static int parse_argv(int argc, char *argv[]) {
break;
case ARG_NETWORK_MACVLAN:
+
+ if (!ifname_valid(optarg)) {
+ log_error("MACVLAN network interface name not valid: %s", optarg);
+ return -EINVAL;
+ }
+
if (strv_extend(&arg_network_macvlan, optarg) < 0)
return log_oom();
@@ -505,6 +523,12 @@ static int parse_argv(int argc, char *argv[]) {
break;
case ARG_NETWORK_IPVLAN:
+
+ if (!ifname_valid(optarg)) {
+ log_error("IPVLAN network interface name not valid: %s", optarg);
+ return -EINVAL;
+ }
+
if (strv_extend(&arg_network_ipvlan, optarg) < 0)
return log_oom();
diff --git a/src/test/test-socket-util.c b/src/test/test-socket-util.c
index 9e01f3afd4..b480fdaa9c 100644
--- a/src/test/test-socket-util.c
+++ b/src/test/test-socket-util.c
@@ -27,6 +27,29 @@
#include "string-util.h"
#include "util.h"
+static void test_ifname_valid(void) {
+ assert(ifname_valid("foo"));
+ assert(ifname_valid("eth0"));
+
+ assert(!ifname_valid("0"));
+ assert(!ifname_valid("99"));
+ assert(ifname_valid("a99"));
+ assert(ifname_valid("99a"));
+
+ assert(!ifname_valid(NULL));
+ assert(!ifname_valid(""));
+ assert(!ifname_valid(" "));
+ assert(!ifname_valid(" foo"));
+ assert(!ifname_valid("bar\n"));
+ assert(!ifname_valid("."));
+ assert(!ifname_valid(".."));
+ assert(ifname_valid("foo.bar"));
+ assert(!ifname_valid("x:y"));
+
+ assert(ifname_valid("xxxxxxxxxxxxxxx"));
+ assert(!ifname_valid("xxxxxxxxxxxxxxxx"));
+}
+
static void test_socket_address_parse(void) {
SocketAddress a;
@@ -362,6 +385,8 @@ int main(int argc, char *argv[]) {
log_set_max_level(LOG_DEBUG);
+ test_ifname_valid();
+
test_socket_address_parse();
test_socket_address_parse_netlink();
test_socket_address_equal();