[PATCH v2 10/13] IB/cma: Validate routing of incoming requests

Haggai Eran
2015-07-26T15:33:49Z

Pass incoming request parameters through the relevant IPv4/IPv6 routing
tables and make sure the network stack is configured to handle such
requests.

Signed-off-by: Haggai Eran <haggaie-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
---
drivers/infiniband/core/cma.c | 95 +++++++++++++++++++++++++++++++++++++++++--
1 file changed, 92 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index ed3d63ad94ac..42f412fde064 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -46,6 +46,8 @@

#include <net/tcp.h>
#include <net/ipv6.h>
+#include <net/ip_fib.h>
+#include <net/ip6_route.h>

#include <rdma/rdma_cm.h>
#include <rdma/rdma_cm_ib.h>
@@ -1078,15 +1080,97 @@ static int cma_save_req_info(const struct ib_cm_event *ib_event,
return 0;
}

+static bool validate_ipv4_net_dev(struct net_device *net_dev,
+ const struct sockaddr_in *dst_addr,
+ const struct sockaddr_in *src_addr)
+{
+ __be32 daddr = dst_addr->sin_addr.s_addr,
+ saddr = src_addr->sin_addr.s_addr;
+ struct fib_result res;
+ struct flowi4 fl4;
+ int err;
+ bool ret;
+
+ if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
+ ipv4_is_lbcast(daddr) || ipv4_is_zeronet(saddr) ||
+ ipv4_is_zeronet(daddr) || ipv4_is_loopback(daddr) ||
+ ipv4_is_loopback(saddr))
+ return false;
+
+ memset(&fl4, 0, sizeof(fl4));
+ fl4.flowi4_iif = net_dev->ifindex;
+ fl4.daddr = daddr;
+ fl4.saddr = saddr;
+
+ rcu_read_lock();
+ err = fib_lookup(dev_net(net_dev), &fl4, &res, 0);
+ if (err)
+ return false;
+
+ ret = FIB_RES_DEV(res) == net_dev;
+ rcu_read_unlock();
+
+ return ret;
+}
+
+static bool validate_ipv6_net_dev(struct net_device *net_dev,
+ const struct sockaddr_in6 *dst_addr,
+ const struct sockaddr_in6 *src_addr)
+{
+#if IS_ENABLED(CONFIG_IPV6)
+ const int strict = ipv6_addr_type(&dst_addr->sin6_addr) &
+ IPV6_ADDR_LINKLOCAL;
+ struct rt6_info *rt = rt6_lookup(dev_net(net_dev), &dst_addr->sin6_addr,
+ &src_addr->sin6_addr, net_dev->ifindex,
+ strict);
+ bool ret;
+
+ if (!rt)
+ return false;
+
+ ret = rt->rt6i_idev->dev == net_dev;
+ ip6_rt_put(rt);
+
+ return ret;
+#else
+ return false;
+#endif
+}
+
+static bool validate_net_dev(struct net_device *net_dev,
+ const struct sockaddr *daddr,
+ const struct sockaddr *saddr)
+{
+ const struct sockaddr_in *daddr4 = (const struct sockaddr_in *)daddr;
+ const struct sockaddr_in *saddr4 = (const struct sockaddr_in *)saddr;
+ const struct sockaddr_in6 *daddr6 = (const struct sockaddr_in6 *)daddr;
+ const struct sockaddr_in6 *saddr6 = (const struct sockaddr_in6 *)saddr;
+
+ switch (daddr->sa_family) {
+ case AF_INET:
+ return saddr->sa_family == AF_INET &&
+ validate_ipv4_net_dev(net_dev, daddr4, saddr4);
+
+ case AF_INET6:
+ return saddr->sa_family == AF_INET6 &&
+ validate_ipv6_net_dev(net_dev, daddr6, saddr6);
+
+ default:
+ return false;
+ }
+}
+
static struct net_device *cma_get_net_dev(struct ib_cm_event *ib_event,
const struct cma_req_info *req)
{
- struct sockaddr_storage listen_addr_storage;
- struct sockaddr *listen_addr = (struct sockaddr *)&listen_addr_storage;
+ struct sockaddr_storage listen_addr_storage, src_addr_storage;
+ struct sockaddr *listen_addr = (struct sockaddr *)&listen_addr_storage,
+ *src_addr = (struct sockaddr *)&src_addr_storage;
struct net_device *net_dev;
int err;

- err = cma_save_ip_info(listen_addr, NULL, ib_event, req->service_id);
+ err = cma_save_ip_info(listen_addr, src_addr, ib_event,
+ req->service_id);
if (err)
return ERR_PTR(err);

@@ -1095,6 +1179,11 @@ static struct net_device *cma_get_net_dev(struct ib_cm_event *ib_event,
if (!net_dev)
return ERR_PTR(-ENODEV);

+ if (!validate_net_dev(net_dev, listen_addr, src_addr)) {
+ dev_put(net_dev);
+ return ERR_PTR(-EHOSTUNREACH);
+ }
+
return net_dev;