iproute: Add magic cookie to route dump file

In order to somehow verify that a blob contains route dump a
4-bytes magic is put at the head of the data and is checked
on restore.

Magic digits are taken from Portland (OR) coordinates :) Is
there any more reliable way of generating such?

Signed-of-by: Pavel Emelyanov <xemul@parallels.com>
This commit is contained in:
Pavel Emelyanov 2012-07-26 18:55:41 +00:00 committed by Stephen Hemminger
parent 1b3c149b41
commit 76c61b34a6

View File

@ -1063,6 +1063,8 @@ static int iproute_flush_cache(void)
return 0;
}
static __u32 route_dump_magic = 0x45311224;
int save_route(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
{
int ret;
@ -1071,11 +1073,6 @@ int save_route(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
struct rtattr *tb[RTA_MAX+1];
int host_len = -1;
if (isatty(STDOUT_FILENO)) {
fprintf(stderr, "Not sending binary stream to stdout\n");
return -1;
}
host_len = calc_host_len(r);
len -= NLMSG_LENGTH(sizeof(*r));
parse_rtattr(tb, RTA_MAX, RTM_RTA(r), len);
@ -1092,6 +1089,24 @@ int save_route(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
return ret == n->nlmsg_len ? 0 : ret;
}
static int save_route_prep(void)
{
int ret;
if (isatty(STDOUT_FILENO)) {
fprintf(stderr, "Not sending binary stream to stdout\n");
return -1;
}
ret = write(STDOUT_FILENO, &route_dump_magic, sizeof(route_dump_magic));
if (ret != sizeof(route_dump_magic)) {
fprintf(stderr, "Can't write magic to dump file\n");
return -1;
}
return 0;
}
static int iproute_list_flush_or_save(int argc, char **argv, int action)
{
int do_ipv6 = preferred_family;
@ -1100,9 +1115,12 @@ static int iproute_list_flush_or_save(int argc, char **argv, int action)
unsigned int mark = 0;
rtnl_filter_t filter_fn;
if (action == IPROUTE_SAVE)
if (action == IPROUTE_SAVE) {
if (save_route_prep())
return -1;
filter_fn = save_route;
else
} else
filter_fn = print_route;
iproute_reset_filter();
@ -1520,8 +1538,30 @@ int restore_handler(const struct sockaddr_nl *nl, struct nlmsghdr *n, void *arg)
return ret;
}
static int route_dump_check_magic(void)
{
int ret;
__u32 magic = 0;
if (isatty(STDIN_FILENO)) {
fprintf(stderr, "Can't restore route dump from a terminal\n");
return -1;
}
ret = fread(&magic, sizeof(magic), 1, stdin);
if (magic != route_dump_magic) {
fprintf(stderr, "Magic mismatch (%d elems, %x magic)\n", ret, magic);
return -1;
}
return 0;
}
int iproute_restore(void)
{
if (route_dump_check_magic())
exit(-1);
exit(rtnl_from_file(stdin, &restore_handler, NULL));
}