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Diffstat (limited to 'netlink.c')
-rw-r--r--netlink.c71
1 files changed, 54 insertions, 17 deletions
diff --git a/netlink.c b/netlink.c
index c07a13c..d93ecda 100644
--- a/netlink.c
+++ b/netlink.c
@@ -185,16 +185,16 @@ unsigned int nl_get_ext_if(sa_family_t af)
}
/**
- * nl_route() - Get/set default gateway for given interface and address family
- * @ns: Use netlink socket in namespace
- * @ifi: Interface index
+ * nl_route() - Get/set/copy routes for given interface and address family
+ * @op: Requested operation
+ * @ifi: Interface index in outer network namespace
+ * @ifi_ns: Interface index in target namespace for NL_SET, NL_DUP
* @af: Address family
- * @gw: Default gateway to fill if zero, to set if not
+ * @gw: Default gateway to fill on NL_GET, to set on NL_SET
*/
-void nl_route(int ns, unsigned int ifi, sa_family_t af, void *gw)
+void nl_route(enum nl_op op, unsigned int ifi, unsigned int ifi_ns,
+ sa_family_t af, void *gw)
{
- int set = (af == AF_INET6 && !IN6_IS_ADDR_UNSPECIFIED(gw)) ||
- (af == AF_INET && *(uint32_t *)gw);
struct req_t {
struct nlmsghdr nlh;
struct rtmsg rtm;
@@ -215,7 +215,7 @@ void nl_route(int ns, unsigned int ifi, sa_family_t af, void *gw)
} r4;
} set;
} req = {
- .nlh.nlmsg_type = set ? RTM_NEWROUTE : RTM_GETROUTE,
+ .nlh.nlmsg_type = op == NL_SET ? RTM_NEWROUTE : RTM_GETROUTE,
.nlh.nlmsg_flags = NLM_F_REQUEST,
.nlh.nlmsg_seq = nl_seq++,
@@ -228,14 +228,15 @@ void nl_route(int ns, unsigned int ifi, sa_family_t af, void *gw)
.rta.rta_len = RTA_LENGTH(sizeof(unsigned int)),
.ifi = ifi,
};
+ unsigned dup_routes = 0;
+ ssize_t n, nlmsgs_size;
struct nlmsghdr *nh;
struct rtattr *rta;
- struct rtmsg *rtm;
char buf[NLBUFSIZ];
- ssize_t n;
+ struct rtmsg *rtm;
size_t na;
- if (set) {
+ if (op == NL_SET) {
if (af == AF_INET6) {
size_t rta_len = RTA_LENGTH(sizeof(req.set.r6.d));
@@ -269,31 +270,67 @@ void nl_route(int ns, unsigned int ifi, sa_family_t af, void *gw)
req.nlh.nlmsg_flags |= NLM_F_DUMP;
}
- if ((n = nl_req(ns, buf, &req, req.nlh.nlmsg_len)) < 0 || set)
+ if ((n = nl_req(op == NL_SET, buf, &req, req.nlh.nlmsg_len)) < 0)
+ return;
+
+ if (op == NL_SET)
return;
nh = (struct nlmsghdr *)buf;
+ nlmsgs_size = n;
+
for ( ; NLMSG_OK(nh, n); nh = NLMSG_NEXT(nh, n)) {
if (nh->nlmsg_type != RTM_NEWROUTE)
goto next;
+ if (op == NL_DUP) {
+ nh->nlmsg_seq = nl_seq++;
+ nh->nlmsg_pid = 0;
+ nh->nlmsg_flags &= ~NLM_F_DUMP_FILTERED;
+ nh->nlmsg_flags |= NLM_F_REQUEST | NLM_F_ACK |
+ NLM_F_CREATE;
+ dup_routes++;
+ }
+
rtm = (struct rtmsg *)NLMSG_DATA(nh);
- if (rtm->rtm_dst_len)
+ if (op == NL_GET && rtm->rtm_dst_len)
continue;
for (rta = RTM_RTA(rtm), na = RTM_PAYLOAD(nh); RTA_OK(rta, na);
rta = RTA_NEXT(rta, na)) {
- if (rta->rta_type != RTA_GATEWAY)
- continue;
+ if (op == NL_GET) {
+ if (rta->rta_type != RTA_GATEWAY)
+ continue;
- memcpy(gw, RTA_DATA(rta), RTA_PAYLOAD(rta));
- return;
+ memcpy(gw, RTA_DATA(rta), RTA_PAYLOAD(rta));
+ return;
+ }
+
+ if (op == NL_DUP && rta->rta_type == RTA_OIF)
+ *(unsigned int *)RTA_DATA(rta) = ifi_ns;
}
next:
if (nh->nlmsg_type == NLMSG_DONE)
break;
}
+
+ if (op == NL_DUP) {
+ char resp[NLBUFSIZ];
+ unsigned i;
+
+ nh = (struct nlmsghdr *)buf;
+ /* Routes might have dependencies between each other, and the
+ * kernel processes RTM_NEWROUTE messages sequentially. For n
+ * valid routes, we might need to send up to n requests to get
+ * all of them inserted. Routes that have been already inserted
+ * won't cause the whole request to fail, so we can simply
+ * repeat the whole request. This approach avoids the need to
+ * calculate dependencies: let the kernel do that.
+ */
+ for (i = 0; i < dup_routes; i++)
+ nl_req(1, resp, nh, nlmsgs_size);
+ }
}
/**