criu: add cmp_version()

We cannot use strcmp(). Otherwise we incorrectly report e.g. that criu 2.12.1
is less than 2.8.

Signed-off-by: Federico Briata <federico-pietro.briata@cnhind.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/src/lxc/criu.c b/src/lxc/criu.c
index f229369cafade48e0bc72e5e0928b90dc78d7903..0e0b25dde4dd4464c7e84b5be5b3ef40c82b91ea 100644 (file)
--- a/src/lxc/criu.c
+++ b/src/lxc/criu.c
@@ -126,6 +126,47 @@ static int load_tty_major_minor(char *directory, char *output, int len)
        return 0;
 }
 
+static int cmp_version(const char *v1, const char *v2)
+{
+       int ret;
+       int oct_v1[3], oct_v2[3];
+
+       memset(oct_v1, -1, sizeof(oct_v1));
+       memset(oct_v2, -1, sizeof(oct_v2));
+
+       ret = sscanf(v1, "%d.%d.%d", &oct_v1[0], &oct_v1[1], &oct_v1[2]);
+       if (ret < 1)
+               return -1;
+
+       ret = sscanf(v2, "%d.%d.%d", &oct_v2[0], &oct_v2[1], &oct_v2[2]);
+       if (ret < 1)
+               return -1;
+
+       /* Major version is greater. */
+       if (oct_v1[0] > oct_v2[0])
+               return 1;
+
+       if (oct_v1[0] < oct_v2[0])
+               return -1;
+
+       /* Minor number is greater.*/
+       if (oct_v1[1] > oct_v2[1])
+               return 1;
+
+       if (oct_v1[1] < oct_v2[1])
+               return -1;
+
+       /* Patch number is greater. */
+       if (oct_v1[2] > oct_v2[2])
+               return 1;
+
+       /* Patch numbers are equal. */
+       if (oct_v1[2] == oct_v2[2])
+               return 0;
+
+       return -1;
+}
+
 static void exec_criu(struct criu_opts *opts)
 {
        char **argv, log[PATH_MAX];
@@ -499,7 +540,7 @@ static void exec_criu(struct criu_opts *opts)
                        struct lxc_netdev *n = it->elem;
                        bool external_not_veth;
 
-                       if (strcmp(opts->criu_version, CRIU_EXTERNAL_NOT_VETH) >= 0) {
+                       if (cmp_version(opts->criu_version, CRIU_EXTERNAL_NOT_VETH) >= 0) {
                                /* Since criu version 2.8 the usage of --veth-pair
                                 * has been deprecated:
                                 * git tag --contains f2037e6d3445fc400