Using mktemp() leads to build time warnings and isn't actually
appropriate for what we want to do as it's checking for the existence of
a file and not a network interface.
Replace those calls by an equivalent mkifname() function which uses the
same template as mktemp but instead checks for existing network
interfaces.
Signed-off-by: Stéphane Graber <stgra...@ubuntu.com>
---
src/lxc/conf.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 57 insertions(+), 3 deletions(-)
diff --git a/src/lxc/conf.c b/src/lxc/conf.c
index 53c05e6..a2f76d3 100644
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -31,6 +31,8 @@
#include <unistd.h>
#include <sys/wait.h>
#include <sys/syscall.h>
+#include <ifaddrs.h>
+#include <time.h>
#if HAVE_PTY_H
#include <pty.h>
@@ -272,6 +274,58 @@ static struct caps_opt caps_opt[] = {
static struct caps_opt caps_opt[] = {};
#endif
+static char padchar[] =
+"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+
+static char *mkifname(char *template)
+{
+ char *name = NULL;
+ int i = 0;
+ FILE *urandom;
+ unsigned int seed;
+ char randstate[2048];
+ struct ifaddrs *ifaddr, *ifa;
+ int ifexists = 0;
+
+ /* Get all the network interfaces */
+ getifaddrs(&ifaddr);
+
+ /* Initialize the random number generator */
+ urandom = fopen ("/dev/urandom", "r");
+ if (urandom != NULL) {
+ if (fread (&seed, sizeof(seed), 1, urandom) <= 0)
+ seed = time(0);
+ fclose(urandom);
+ }
+ else
+ seed = time(0);
+ initstate(seed, randstate, 256);
+
+ /* Generate random names until we find one that doesn't exist */
+ while(1) {
+ ifexists = 0;
+ name = strdup(template);
+ for (i = 0; i < strlen(name); i++) {
+ if (name[i] == 'X') {
+ name[i] = padchar[random() % strlen(padchar)];
+ }
+ }
+
+ for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) {
+ if (strcmp(ifa->ifa_name, name) == 0) {
+ ifexists = 1;
+ break;
+ }
+ }
+
+ if (ifexists == 0)
+ break;
+ }
+
+ freeifaddrs(ifaddr);
+ return name;
+}
+
static int run_buffer(char *buffer)
{
FILE *f;
@@ -2174,13 +2228,13 @@ static int instanciate_veth(struct lxc_handler
*handler, struct lxc_netdev *netd
ERROR("veth1 name too long");
return -1;
}
- veth1 = mktemp(veth1buf);
+ veth1 = mkifname(veth1buf);
/* store away for deconf */
memcpy(netdev->priv.veth_attr.veth1, veth1, IFNAMSIZ);
}
snprintf(veth2buf, sizeof(veth2buf), "vethXXXXXX");
- veth2 = mktemp(veth2buf);
+ veth2 = mkifname(veth2buf);
if (!strlen(veth1) || !strlen(veth2)) {
ERROR("failed to allocate a temporary name");
@@ -2286,7 +2340,7 @@ static int instanciate_macvlan(struct lxc_handler
*handler, struct lxc_netdev *n
if (err >= sizeof(peerbuf))
return -1;
- peer = mktemp(peerbuf);
+ peer = mkifname(peerbuf);
if (!strlen(peer)) {
ERROR("failed to make a temporary name");
return -1;
--
1.8.3.2
------------------------------------------------------------------------------
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