UCT/UD: Filter incoming packets by DGID

src/uct/ib/ud/accel/ud_mlx5.c

@@ -400,17 +400,22 @@ uct_ud_mlx5_iface_poll_rx(uct_ud_mlx5_iface_t *iface, int is_async)
 
     iface->super.rx.available++;
     iface->rx.wq.cq_wqe_counter++;
-
-    len = ntohl(cqe->byte_cnt);
+    count = 1;
+    len   = ntohl(cqe->byte_cnt);
     VALGRIND_MAKE_MEM_DEFINED(packet, len);
+
+    if (!uct_ud_iface_check_grh(&iface->super, packet + UCT_IB_GRH_LEN,
+                                (ntohl(cqe->flags_rqpn) >> 28) & 3)) {
+        ucs_mpool_put_inline(desc);
+        goto out;
+    }
+
     uct_ib_mlx5_log_rx(&iface->super.super, IBV_QPT_UD, cqe, packet,
                        uct_ud_dump_packet);
     uct_ud_ep_process_rx(&iface->super,
                          (uct_ud_neth_t *)(packet + UCT_IB_GRH_LEN),
                          len - UCT_IB_GRH_LEN,
                          (uct_ud_recv_skb_t *)desc, is_async);
-    count = 1;
-
 out:
     if (iface->super.rx.available >= iface->super.super.config.rx_max_batch) {
         /* we need to try to post buffers always. Otherwise it is possible

src/uct/ib/ud/base/ud_iface.c

@@ -14,6 +14,7 @@
 #include <ucs/type/class.h>
 #include <ucs/datastruct/queue.h>
 #include <sys/poll.h>
+#include <linux/ip.h>
 
 
 SGLIB_DEFINE_LIST_FUNCTIONS(uct_ud_iface_peer_t, uct_ud_iface_peer_cmp, next)
@@ -371,6 +372,39 @@ void uct_ud_iface_remove_async_handlers(uct_ud_iface_t *iface)
     ucs_async_remove_handler(iface->async.timer_id, 1);
 }
 
+/* Calculate real GIDs len. Can be either 16 (RoCEv1 or RoCEv2/IPv6)
+ * or 4 (RoCEv2/IPv4). This len is used for packets filtering by DGIDs.
+ *
+ * According to Annex17_RoCEv2 (A17.4.5.2):
+ * "The first 40 bytes of user posted UD Receive Buffers are reserved for the L3
+ * header of the incoming packet (as per the InfiniBand Spec Section 11.4.1.2).
+ * In RoCEv2, this area is filled up with the IP header. IPv6 header uses the
+ * entire 40 bytes. IPv4 headers use the 20 bytes in the second half of the
+ * reserved 40 bytes area (i.e. offset 20 from the beginning of the receive
+ * buffer). In this case, the content of the first 20 bytes is undefined." */
+static void uct_ud_iface_calc_gid_len(uct_ud_iface_t *iface)
+{
+    const int ipv4_len      = sizeof(struct in_addr);
+    const int ipv6_len      = sizeof(struct in6_addr);
+    uint16_t *local_gid_u16 = (uint16_t*)iface->super.gid.raw;
+
+    /* Make sure that daddr in IPv4 resides in the last 4 bytes in GRH */
+    UCS_STATIC_ASSERT((UCT_IB_GRH_LEN - (20 + offsetof(struct iphdr, daddr))) == ipv4_len);
+
+    /* Make sure that dgid resides in the last 16 bytes in GRH */
+    UCS_STATIC_ASSERT(UCT_IB_GRH_LEN - offsetof(struct ibv_grh, dgid) == ipv6_len);
+
+    /* IPv4 mapped to IPv6 looks like: 0000:0000:0000:0000:0000:ffff:????:????,
+     * so check for leading zeroes and verify that 11-12 bytes are 0xff.
+     * Otherwise either RoCEv1 or RoCEv2/IPv6 are used. */
+    if (local_gid_u16[0] == 0x0000) {
+        ucs_assert_always(local_gid_u16[5] == 0xffff);
+        iface->config.gid_len = ipv4_len;
+    } else {
+        iface->config.gid_len = ipv6_len;
+    }
+}
+
 UCS_CLASS_INIT_FUNC(uct_ud_iface_t, uct_ud_iface_ops_t *ops, uct_md_h md,
                     uct_worker_h worker, const uct_iface_params_t *params,
                     unsigned ud_rx_priv_len,
@@ -418,6 +452,8 @@ UCS_CLASS_INIT_FUNC(uct_ud_iface_t, uct_ud_iface_ops_t *ops, uct_md_h md,
     self->rx.available           = config->super.rx.queue_len;
     self->config.tx_qp_len       = config->super.tx.queue_len;
     self->config.peer_timeout    = ucs_time_from_sec(config->peer_timeout);
+    self->config.check_grh_dgid  = (config->dgid_check &&
+                                    (self->super.addr_type == UCT_IB_ADDRESS_TYPE_ETH));
 
     if (config->slow_timer_backoff <= 0.) {
         ucs_error("The slow timer back off should be > 0 (%lf)",
@@ -469,6 +505,8 @@ UCS_CLASS_INIT_FUNC(uct_ud_iface_t, uct_ud_iface_ops_t *ops, uct_md_h md,
 
     ucs_queue_head_init(&self->rx.pending_q);
 
+    uct_ud_iface_calc_gid_len(self);
+
     return UCS_OK;
 
 err_mpool:
@@ -511,6 +549,10 @@ ucs_config_field_t uct_ud_iface_config_table[] = {
     {"SLOW_TIMER_BACKOFF", "2.0", "Timeout multiplier for resending trigger",
      ucs_offsetof(uct_ud_iface_config_t, slow_timer_backoff),
                   UCS_CONFIG_TYPE_DOUBLE},
+    {"ETH_DGID_CHECK", "y",
+     "Enable checking destination GID for incoming packets of Ethernet network\n"
+     "Mismatched packets are silently dropped.",
+     ucs_offsetof(uct_ud_iface_config_t, dgid_check), UCS_CONFIG_TYPE_BOOL},
     {NULL}
 };
 

src/uct/ib/ud/base/ud_iface.h

@@ -30,6 +30,7 @@ typedef struct uct_ud_iface_config {
     uct_ib_iface_config_t    super;
     double                   peer_timeout;
     double                   slow_timer_backoff;
+    int                      dgid_check;
 } uct_ud_iface_config_t;
 
 struct uct_ud_iface_peer {
@@ -123,6 +124,8 @@ struct uct_ud_iface {
         double               slow_timer_backoff;
         unsigned             tx_qp_len;
         unsigned             max_inline;
+        int                  check_grh_dgid;
+        unsigned             gid_len;
     } config;
     ucs_ptr_array_t       eps;
     uct_ud_iface_peer_t  *peers[UCT_UD_HASH_SIZE];
@@ -215,6 +218,31 @@ static UCS_F_ALWAYS_INLINE void uct_ud_leave(uct_ud_iface_t *iface)
     UCS_ASYNC_UNBLOCK(iface->super.super.worker->async);
 }
 
+static UCS_F_ALWAYS_INLINE int
+uct_ud_iface_check_grh(uct_ud_iface_t *iface, void *grh_end, int is_grh_present)
+{
+    void *dest_gid, *local_gid;
+
+    if (!iface->config.check_grh_dgid) {
+        return 1;
+    }
+
+    if (ucs_unlikely(!is_grh_present)) {
+        ucs_warn("RoCE packet does not contain GRH");
+        return 1;
+    }
+
+    local_gid = (char*)iface->super.gid.raw + (16 - iface->config.gid_len);
+    dest_gid  = (char*)grh_end - iface->config.gid_len;
+
+    if (memcmp(local_gid, dest_gid, iface->config.gid_len)) {
+        ucs_trace_data("Drop packet with wrong dgid");
+        return 0;
+    }
+
+    return 1;
+}
+
 /*
 management of connecting endpoints (cep)
 

src/uct/ib/ud/verbs/ud_verbs.c

@@ -326,6 +326,11 @@ uct_ud_verbs_iface_poll_rx(uct_ud_verbs_iface_t *iface, int is_async)
     }
 
     UCT_IB_IFACE_VERBS_FOREACH_RXWQE(&iface->super.super, i, packet, wc, num_wcs) {
+        if (!uct_ud_iface_check_grh(&iface->super, packet + UCT_IB_GRH_LEN,
+                                    wc[i].wc_flags & IBV_WC_GRH)) {
+            ucs_mpool_put_inline((void*)wc[i].wr_id);
+            continue;
+        }
         uct_ib_log_recv_completion(&iface->super.super, IBV_QPT_UD, &wc[i],
                                    packet, wc[i].byte_len, uct_ud_dump_packet);
         uct_ud_ep_process_rx(&iface->super,