diff mbox series

[ovs-dev] ipf: add ipf context

Message ID 20211030061231.55815-1-hepeng.0320@bytedance.com
State Changes Requested
Headers show
Series [ovs-dev] ipf: add ipf context | expand

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Context Check Description
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ovsrobot/github-robot-_Build_and_Test success github build: passed

Commit Message

Peng He Oct. 30, 2021, 6:12 a.m. UTC 
ipf_postprocess will emit packets into the datapath pipeline ignoring
the conntrack context, this might casuse weird issues when a packet
batch has less space to contain all the fragments belonging to single
packet.

Given the below ruleest and consider sending a 64K ICMP packet which
is splitted into 64 fragments.

priority=1,action=drop
priority=10,arp,action=normal
priority=100,in_port=1,ct_state=-trk,icmp,action=ct(zone=9,table=0)
priority=100,in_port=1,ct_state=+new+trk,icmp,action=ct(zone=9,commit),2
priority=100,in_port=1,ct_state=-new+est+trk,icmp,action=2
priority=100,in_port=2,ct_state=-trk,icmp,action=ct(table=0,zone=9)
priority=100,in_port=2,ct_state=+trk+est-new,icmp,action=1

Batch 1:
the first 32 packets will be buffered in the ipf preprocessing, nothing
more proceeds.

Batch 2:
the second 32 packets succeed the fragment reassembly and goes to ct
and ipf_post will emits the first 32 packets due to the limit of batch
size.

the first 32 packets goes to the datapath again due to the
recirculation, and again buffered at ipf preprocessing before ct,
then the ovs tries to call ct commit and ipf_postprocessing which emits
the last 32 packets, in this case the last 32 packets will follow
the current action list which will be sent to port 2 directly without
recirculation and going to ipf preprocssing again.

This will cause the first 32 packets never get the chance to
reassemble and evevntually this large ICMP packets fail to transmit.

this patch fixes this issue by adding firstly ipf context to avoid
ipf_postprocessing emits packets in the wrong context. Then by
re-executing the action list again to emit the last 32 packets
in the right context to correctly transmitting multiple fragments.
---
 lib/conntrack.c         | 10 ++++----
 lib/conntrack.h         | 14 +++++------
 lib/dpif-netdev.c       | 41 +++++++++++++++++++++++++++----
 lib/ipf.c               | 53 +++++++++++++++++++++++++++++++++++------
 lib/ipf.h               | 12 +++++++---
 tests/system-traffic.at | 33 +++++++++++++++++++++++++
 6 files changed, 136 insertions(+), 27 deletions(-)

Comments

0-day Robot Oct. 30, 2021, 6:18 a.m. UTC | #1 
Bleep bloop.  Greetings Peng He, I am a robot and I have tried out your patch.
Thanks for your contribution.

I encountered some error that I wasn't expecting.  See the details below.


checkpatch:
ERROR: Author Peng He <xnhp0320@gmail.com> needs to sign off.
WARNING: Line is 85 characters long (recommended limit is 79)
#74 FILE: lib/conntrack.c:1447:
    struct ipf_ctx *ipf_ctx = dp_packet_batch_is_empty(pkt_batch) ? NULL : &_ipf_ctx;

WARNING: Line is 80 characters long (recommended limit is 79)
#86 FILE: lib/conntrack.c:1474:
    return ipf_postprocess_conntrack(ct->ipf, pkt_batch, ipf_ctx, now, dl_type);

WARNING: Line is 80 characters long (recommended limit is 79)
#106 FILE: lib/conntrack.h:92:
                       ovs_be16 dl_type, bool force, bool commit, uint16_t zone,

WARNING: Line is 89 characters long (recommended limit is 79)
#136 FILE: lib/dpif-netdev.c:8289:
        more_pkts = conntrack_execute(dp->conntrack, packets_, aux->flow->dl_type, force,

WARNING: Line is 89 characters long (recommended limit is 79)
#137 FILE: lib/dpif-netdev.c:8290:
                                      commit, zone, setmark, setlabel, aux->flow->tp_src,

WARNING: Line is 85 characters long (recommended limit is 79)
#138 FILE: lib/dpif-netdev.c:8291:
                                      aux->flow->tp_dst, helper, nat_action_info_ref,

ERROR: Improper whitespace around control block
#157 FILE: lib/dpif-netdev.c:8336:
    NL_ATTR_FOR_EACH_UNSAFE(a, left, actions, actions_len) {

WARNING: Line is 80 characters long (recommended limit is 79)
#183 FILE: lib/dpif-netdev.c:8361:
                                                              aux.redo_actions);

WARNING: Line is 93 characters long (recommended limit is 79)
#270 FILE: lib/ipf.c:1260:
                         struct ipf_ctx *ctx, long long now, ovs_be16 dl_type, uint16_t zone,

WARNING: Line is 98 characters long (recommended limit is 79)
#321 FILE: lib/ipf.h:52:
                              struct ipf_ctx *ctx, long long now, ovs_be16 dl_type, uint16_t zone,

WARNING: Line is 85 characters long (recommended limit is 79)
#327 FILE: lib/ipf.h:56:
                               struct ipf_ctx *ctx, long long now, ovs_be16 dl_type);

Lines checked: 377, Warnings: 10, Errors: 2


Please check this out.  If you feel there has been an error, please email aconole@redhat.com

Thanks,
0-day Robot
Aaron Conole Nov. 2, 2021, 3:21 p.m. UTC | #2 
Hi Peng,

Peng He <xnhp0320@gmail.com> writes:

> ipf_postprocess will emit packets into the datapath pipeline ignoring
> the conntrack context, this might casuse weird issues when a packet
> batch has less space to contain all the fragments belonging to single
> packet.
>
> Given the below ruleest and consider sending a 64K ICMP packet which
> is splitted into 64 fragments.
>
> priority=1,action=drop
> priority=10,arp,action=normal
> priority=100,in_port=1,ct_state=-trk,icmp,action=ct(zone=9,table=0)
> priority=100,in_port=1,ct_state=+new+trk,icmp,action=ct(zone=9,commit),2
> priority=100,in_port=1,ct_state=-new+est+trk,icmp,action=2
> priority=100,in_port=2,ct_state=-trk,icmp,action=ct(table=0,zone=9)
> priority=100,in_port=2,ct_state=+trk+est-new,icmp,action=1
>
> Batch 1:
> the first 32 packets will be buffered in the ipf preprocessing, nothing
> more proceeds.
>
> Batch 2:
> the second 32 packets succeed the fragment reassembly and goes to ct
> and ipf_post will emits the first 32 packets due to the limit of batch
> size.
>
> the first 32 packets goes to the datapath again due to the
> recirculation, and again buffered at ipf preprocessing before ct,
> then the ovs tries to call ct commit and ipf_postprocessing which emits
> the last 32 packets, in this case the last 32 packets will follow
> the current action list which will be sent to port 2 directly without
> recirculation and going to ipf preprocssing again.
>
> This will cause the first 32 packets never get the chance to
> reassemble and evevntually this large ICMP packets fail to transmit.
>
> this patch fixes this issue by adding firstly ipf context to avoid
> ipf_postprocessing emits packets in the wrong context. Then by
> re-executing the action list again to emit the last 32 packets
> in the right context to correctly transmitting multiple fragments.
> ---

There are quite a few splats from checkpatch checks.  I will look a bit
closer when v2 comes around.  Thank you also for adding a unit test with
it to showcase the issue.
diff mbox series

Patch

diff --git a/lib/conntrack.c b/lib/conntrack.c
index 33a1a9295..a37993d9d 100644
--- a/lib/conntrack.c
+++ b/lib/conntrack.c
@@ -1434,7 +1434,7 @@  process_one(struct conntrack *ct, struct dp_packet *pkt,
  * connection tables.  'setmark', if not NULL, should point to a two
  * elements array containing a value and a mask to set the connection mark.
  * 'setlabel' behaves similarly for the connection label.*/
-int
+bool
 conntrack_execute(struct conntrack *ct, struct dp_packet_batch *pkt_batch,
                   ovs_be16 dl_type, bool force, bool commit, uint16_t zone,
                   const uint32_t *setmark,
@@ -1443,7 +1443,9 @@  conntrack_execute(struct conntrack *ct, struct dp_packet_batch *pkt_batch,
                   const struct nat_action_info_t *nat_action_info,
                   long long now, uint32_t tp_id)
 {
-    ipf_preprocess_conntrack(ct->ipf, pkt_batch, now, dl_type, zone,
+    struct ipf_ctx _ipf_ctx;
+    struct ipf_ctx *ipf_ctx = dp_packet_batch_is_empty(pkt_batch) ? NULL : &_ipf_ctx;
+    ipf_preprocess_conntrack(ct->ipf, pkt_batch, ipf_ctx, now, dl_type, zone,
                              ct->hash_basis);
 
     struct dp_packet *packet;
@@ -1468,9 +1470,7 @@  conntrack_execute(struct conntrack *ct, struct dp_packet_batch *pkt_batch,
         }
     }
 
-    ipf_postprocess_conntrack(ct->ipf, pkt_batch, now, dl_type);
-
-    return 0;
+    return ipf_postprocess_conntrack(ct->ipf, pkt_batch, ipf_ctx, now, dl_type);
 }
 
 void
diff --git a/lib/conntrack.h b/lib/conntrack.h
index 9553b188a..7772444fd 100644
--- a/lib/conntrack.h
+++ b/lib/conntrack.h
@@ -88,13 +88,13 @@  struct nat_action_info_t {
 struct conntrack *conntrack_init(void);
 void conntrack_destroy(struct conntrack *);
 
-int conntrack_execute(struct conntrack *ct, struct dp_packet_batch *pkt_batch,
-                      ovs_be16 dl_type, bool force, bool commit, uint16_t zone,
-                      const uint32_t *setmark,
-                      const struct ovs_key_ct_labels *setlabel,
-                      ovs_be16 tp_src, ovs_be16 tp_dst, const char *helper,
-                      const struct nat_action_info_t *nat_action_info,
-                      long long now, uint32_t tp_id);
+bool conntrack_execute(struct conntrack *ct, struct dp_packet_batch *pkt_batch,
+                       ovs_be16 dl_type, bool force, bool commit, uint16_t zone,
+                       const uint32_t *setmark,
+                       const struct ovs_key_ct_labels *setlabel,
+                       ovs_be16 tp_src, ovs_be16 tp_dst, const char *helper,
+                       const struct nat_action_info_t *nat_action_info,
+                       long long now, uint32_t tp_id);
 void conntrack_clear(struct dp_packet *packet);
 
 struct conntrack_dump {
diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index b078c2da5..127a22d04 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -7755,6 +7755,7 @@  dp_netdev_recirculate(struct dp_netdev_pmd_thread *pmd,
 struct dp_netdev_execute_aux {
     struct dp_netdev_pmd_thread *pmd;
     const struct flow *flow;
+    const struct nlattr *redo_actions;
 };
 
 static void
@@ -8284,10 +8285,14 @@  dp_execute_cb(void *aux_, struct dp_packet_batch *packets_,
             VLOG_WARN_RL(&rl, "NAT specified without commit.");
         }
 
-        conntrack_execute(dp->conntrack, packets_, aux->flow->dl_type, force,
-                          commit, zone, setmark, setlabel, aux->flow->tp_src,
-                          aux->flow->tp_dst, helper, nat_action_info_ref,
-                          pmd->ctx.now / 1000, tp_id);
+        bool more_pkts;
+        more_pkts = conntrack_execute(dp->conntrack, packets_, aux->flow->dl_type, force,
+                                      commit, zone, setmark, setlabel, aux->flow->tp_src,
+                                      aux->flow->tp_dst, helper, nat_action_info_ref,
+                                      pmd->ctx.now / 1000, tp_id);
+        if (more_pkts) {
+            aux->redo_actions = a;
+        }
         break;
     }
 
@@ -8321,16 +8326,42 @@  dp_execute_cb(void *aux_, struct dp_packet_batch *packets_,
     dp_packet_delete_batch(packets_, should_steal);
 }
 
+static size_t
+dp_netdev_find_actions_left(const struct nlattr *actions,
+                            size_t actions_len,
+                            const struct nlattr *target)
+{
+    const struct nlattr *a;
+    size_t left;
+    NL_ATTR_FOR_EACH_UNSAFE(a, left, actions, actions_len) {
+        if (a == target) {
+            break;
+        }
+    }
+    return left;
+}
+
 static void
 dp_netdev_execute_actions(struct dp_netdev_pmd_thread *pmd,
                           struct dp_packet_batch *packets,
                           bool should_steal, const struct flow *flow,
                           const struct nlattr *actions, size_t actions_len)
 {
-    struct dp_netdev_execute_aux aux = { pmd, flow };
+    struct dp_netdev_execute_aux aux = { pmd, flow, NULL };
 
     odp_execute_actions(&aux, packets, should_steal, actions,
                         actions_len, dp_execute_cb);
+
+    if (OVS_UNLIKELY(aux.redo_actions)) {
+
+        struct dp_packet_batch batch;
+        dp_packet_batch_init(&batch);
+        size_t redo_actions_len = dp_netdev_find_actions_left(actions, \
+                                                              actions_len, \
+                                                              aux.redo_actions);
+        dp_netdev_execute_actions(pmd, &batch, should_steal, flow,
+                                  aux.redo_actions, redo_actions_len);
+    }
 }
 
 struct dp_netdev_ct_dump {
diff --git a/lib/ipf.c b/lib/ipf.c
index 507db2aea..eb8fe87bd 100644
--- a/lib/ipf.c
+++ b/lib/ipf.c
@@ -1046,30 +1046,52 @@  ipf_send_frags_in_list(struct ipf *ipf, struct ipf_list *ipf_list,
     OVS_NOT_REACHED();
 }
 
+static bool
+ipf_ctx_eq(struct ipf_list *ipf_list, struct ipf_ctx *ctx)
+{
+    struct dp_packet *pkt =
+        ipf_list->frag_list[ipf_list->last_sent_idx + 1].pkt;
+
+    if (pkt->md.recirc_id != ctx->recirc_id ||
+            pkt->md.in_port.odp_port != ctx->in_port.odp_port ||
+            pkt->md.ct_zone != ctx->zone) {
+        return false;
+    }
+    return true;
+}
+
 /* Adds fragments associated with a completed fragment list to a packet batch
  * to be processed by the calling application, typically conntrack. Also
  * cleans up the list context when it is empty.*/
-static void
+static bool
 ipf_send_completed_frags(struct ipf *ipf, struct dp_packet_batch *pb,
-                         long long now, bool v6)
+                         struct ipf_ctx *ctx, long long now, bool v6)
 {
     if (ovs_list_is_empty(&ipf->frag_complete_list)) {
-        return;
+        return false;
     }
 
+    bool more_pkts = false;
     ovs_mutex_lock(&ipf->ipf_lock);
     struct ipf_list *ipf_list, *next;
 
     LIST_FOR_EACH_SAFE (ipf_list, next, list_node, &ipf->frag_complete_list) {
+
+        if (ctx && !ipf_ctx_eq(ipf_list, ctx)) {
+            continue;
+        }
+
         if (ipf_send_frags_in_list(ipf, ipf_list, pb, IPF_FRAG_COMPLETED_LIST,
                                    v6, now)) {
             ipf_completed_list_clean(&ipf->frag_lists, ipf_list);
         } else {
+            more_pkts = true;
             break;
         }
     }
 
     ovs_mutex_unlock(&ipf->ipf_lock);
+    return more_pkts;
 }
 
 /* Conservatively adds fragments associated with a expired fragment list to
@@ -1220,14 +1242,29 @@  ipf_post_execute_reass_pkts(struct ipf *ipf,
     ovs_mutex_unlock(&ipf->ipf_lock);
 }
 
+static void
+ipf_ctx_save(struct ipf_ctx *ctx, struct dp_packet_batch *pb, uint16_t zone)
+{
+    if (ctx) {
+        ctx->recirc_id = pb->packets[0]->md.recirc_id;
+        ctx->in_port.odp_port = pb->packets[0]->md.in_port.odp_port;
+        ctx->zone = zone;
+    }
+}
+
 /* Extracts any fragments from the batch and reassembles them when a
  * complete packet is received.  Completed packets are attempted to
  * be added to the batch to be sent through conntrack. */
 void
 ipf_preprocess_conntrack(struct ipf *ipf, struct dp_packet_batch *pb,
-                         long long now, ovs_be16 dl_type, uint16_t zone,
+                         struct ipf_ctx *ctx, long long now, ovs_be16 dl_type, uint16_t zone,
                          uint32_t hash_basis)
 {
+    /* No matter if ipf is enabled or not, we should save the ctx,
+     * because ipf_postprocess will emit packets not matter ipf is
+     * enabled or not
+     */
+    ipf_ctx_save(ctx, pb, zone);
     if (ipf_get_enabled(ipf)) {
         ipf_extract_frags_from_batch(ipf, pb, dl_type, zone, now, hash_basis);
     }
@@ -1241,16 +1278,18 @@  ipf_preprocess_conntrack(struct ipf *ipf, struct dp_packet_batch *pb,
  * through conntrack and adds these fragments to any batches seen.  Expired
  * fragments are marked as invalid and also added to the batches seen
  * with low priority.  Reassembled packets are freed. */
-void
+bool
 ipf_postprocess_conntrack(struct ipf *ipf, struct dp_packet_batch *pb,
-                          long long now, ovs_be16 dl_type)
+                          struct ipf_ctx *ctx, long long now, ovs_be16 dl_type)
 {
+    bool more_pkts = false;
     if (ipf_get_enabled(ipf) || atomic_count_get(&ipf->nfrag)) {
         bool v6 = dl_type == htons(ETH_TYPE_IPV6);
         ipf_post_execute_reass_pkts(ipf, pb, v6);
-        ipf_send_completed_frags(ipf, pb, now, v6);
+        more_pkts = ipf_send_completed_frags(ipf, pb, ctx, now, v6);
         ipf_send_expired_frags(ipf, pb, now, v6);
     }
+    return more_pkts;
 }
 
 static void *
diff --git a/lib/ipf.h b/lib/ipf.h
index 6ac91b270..1fa040cd1 100644
--- a/lib/ipf.h
+++ b/lib/ipf.h
@@ -40,14 +40,20 @@  struct ipf_status {
    unsigned int nfrag_max;
 };
 
+struct ipf_ctx {
+    uint32_t recirc_id;
+    union flow_in_port in_port; /* Input port. */
+    uint16_t zone;
+};
+
 struct ipf *ipf_init(void);
 void ipf_destroy(struct ipf *ipf);
 void ipf_preprocess_conntrack(struct ipf *ipf, struct dp_packet_batch *pb,
-                              long long now, ovs_be16 dl_type, uint16_t zone,
+                              struct ipf_ctx *ctx, long long now, ovs_be16 dl_type, uint16_t zone,
                               uint32_t hash_basis);
 
-void ipf_postprocess_conntrack(struct ipf *ipf, struct dp_packet_batch *pb,
-                               long long now, ovs_be16 dl_type);
+bool ipf_postprocess_conntrack(struct ipf *ipf, struct dp_packet_batch *pb,
+                               struct ipf_ctx *ctx, long long now, ovs_be16 dl_type);
 
 int ipf_set_enabled(struct ipf *ipf, bool v6, bool enable);
 int ipf_set_min_frag(struct ipf *ipf, bool v6, uint32_t value);
diff --git a/tests/system-traffic.at b/tests/system-traffic.at
index 092de308b..ca9c4d7ea 100644
--- a/tests/system-traffic.at
+++ b/tests/system-traffic.at
@@ -2705,6 +2705,39 @@  DPCTL_CHECK_FRAGMENTATION_PASS()
 OVS_TRAFFIC_VSWITCHD_STOP
 AT_CLEANUP
 
+AT_SETUP([conntrack - IPv4 large fragmentation])
+CHECK_CONNTRACK()
+OVS_TRAFFIC_VSWITCHD_START()
+
+ADD_NAMESPACES(at_ns0, at_ns1)
+
+ADD_VETH(p0, at_ns0, br0, "10.1.1.1/24")
+ADD_VETH(p1, at_ns1, br0, "10.1.1.2/24")
+
+dnl Sending ping through conntrack
+AT_DATA([flows.txt], [dnl
+priority=1,action=drop
+priority=10,arp,action=normal
+priority=100,in_port=1,ct_state=-trk,icmp,action=ct(zone=9,table=0)
+priority=100,in_port=1,ct_state=+new+trk,icmp,action=ct(zone=9,commit),2
+priority=100,in_port=1,ct_state=-new+est+trk,icmp,action=2
+priority=100,in_port=2,ct_state=-trk,icmp,action=ct(table=0,zone=9)
+priority=100,in_port=2,ct_state=+trk+est-new,icmp,action=1
+])
+
+AT_CHECK([ovs-ofctl --bundle add-flows br0 flows.txt])
+
+dnl Modify userspace conntrack fragmentation handling.
+DPCTL_MODIFY_FRAGMENTATION()
+
+dnl Ipv4 larger fragmentation connectivity check.
+NS_CHECK_EXEC([at_ns0], [ping -s 65000 -q -c 3 -i 0.3 -w 2 10.1.1.2 | FORMAT_PING], [0], [dnl
+3 packets transmitted, 3 received, 0% packet loss, time 0ms
+])
+
+OVS_TRAFFIC_VSWITCHD_STOP
+AT_CLEANUP
+
 AT_SETUP([conntrack - IPv4 fragmentation expiry])
 CHECK_CONNTRACK()
 OVS_TRAFFIC_VSWITCHD_START()