sctp: add SCTP_AUTH_NO_AUTH type for AUTHENTICATION_EVENT

This patch is to add SCTP_AUTH_NO_AUTH type for AUTHENTICATION_EVENT,
as described in section 6.1.8 of RFC6458.

      SCTP_AUTH_NO_AUTH:  This report indicates that the peer does not
         support SCTP authentication as defined in [RFC4895].

Note that the implementation is quite similar as that of
SCTP_ADAPTATION_INDICATION.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 56 insertions, 2 deletions

diff --git a/include/net/sctp/command.h b/include/net/sctp/command.h
index b55c6a48a206..6640f84fe536 100644
--- a/include/net/sctp/command.h
+++ b/include/net/sctp/command.h
@@ -100,6 +100,7 @@ enum sctp_verb {
         SCTP_CMD_SET_SK_ERR,     /* Set sk_err */
         SCTP_CMD_ASSOC_CHANGE,   /* generate and send assoc_change event */
         SCTP_CMD_ADAPTATION_IND, /* generate and send adaptation event */
+        SCTP_CMD_PEER_NO_AUTH,   /* generate and send authentication event */
         SCTP_CMD_ASSOC_SHKEY,    /* generate the association shared keys */
         SCTP_CMD_T1_RETRAN,      /* Mark for retransmission after T1 timeout  */
         SCTP_CMD_UPDATE_INITTAG, /* Update peer inittag */
diff --git a/include/uapi/linux/sctp.h b/include/uapi/linux/sctp.h
index 18ebbfeee4af..afd4346386e0 100644
--- a/include/uapi/linux/sctp.h
+++ b/include/uapi/linux/sctp.h
@@ -522,6 +522,7 @@ enum {
         SCTP_AUTH_NEW_KEY,
 #define SCTP_AUTH_NEWKEY        SCTP_AUTH_NEW_KEY /* compatible with before */
         SCTP_AUTH_FREE_KEY,
+        SCTP_AUTH_NO_AUTH,
 };
 
 /*
diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c
index b71e7fb0a20a..298112ca8c06 100644
--- a/net/sctp/sm_sideeffect.c
+++ b/net/sctp/sm_sideeffect.c
@@ -1049,6 +1049,16 @@ static void sctp_cmd_assoc_change(struct sctp_cmd_seq *commands,
                 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
 }
 
+static void sctp_cmd_peer_no_auth(struct sctp_cmd_seq *commands,
+                                  struct sctp_association *asoc)
+{
+        struct sctp_ulpevent *ev;
+
+        ev = sctp_ulpevent_make_authkey(asoc, 0, SCTP_AUTH_NO_AUTH, GFP_ATOMIC);
+        if (ev)
+                asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
+}
+
 /* Helper function to generate an adaptation indication event */
 static void sctp_cmd_adaptation_ind(struct sctp_cmd_seq *commands,
                                     struct sctp_association *asoc)
@@ -1755,6 +1765,9 @@ static int sctp_cmd_interpreter(enum sctp_event event_type,
                 case SCTP_CMD_ADAPTATION_IND:
                         sctp_cmd_adaptation_ind(commands, asoc);
                         break;
+                case SCTP_CMD_PEER_NO_AUTH:
+                        sctp_cmd_peer_no_auth(commands, asoc);
+                        break;
 
                 case SCTP_CMD_ASSOC_SHKEY:
                         error = sctp_auth_asoc_init_active_key(asoc,
diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index 1e41dee70b51..cc56a67dbb4d 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -659,7 +659,7 @@ enum sctp_disposition sctp_sf_do_5_1D_ce(struct net *net,
                                          void *arg,
                                          struct sctp_cmd_seq *commands)
 {
-        struct sctp_ulpevent *ev, *ai_ev = NULL;
+        struct sctp_ulpevent *ev, *ai_ev = NULL, *auth_ev = NULL;
         struct sctp_association *new_asoc;
         struct sctp_init_chunk *peer_init;
         struct sctp_chunk *chunk = arg;
@@ -820,6 +820,14 @@ enum sctp_disposition sctp_sf_do_5_1D_ce(struct net *net,
                         goto nomem_aiev;
         }
 
+        if (!new_asoc->peer.auth_capable) {
+                auth_ev = sctp_ulpevent_make_authkey(new_asoc, 0,
+                                                     SCTP_AUTH_NO_AUTH,
+                                                     GFP_ATOMIC);
+                if (!auth_ev)
+                        goto nomem_authev;
+        }
+
         /* Add all the state machine commands now since we've created
          * everything.  This way we don't introduce memory corruptions
          * during side-effect processing and correclty count established
@@ -847,8 +855,14 @@ enum sctp_disposition sctp_sf_do_5_1D_ce(struct net *net,
                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
                                 SCTP_ULPEVENT(ai_ev));
 
+        if (auth_ev)
+                sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
+                                SCTP_ULPEVENT(auth_ev));
+
         return SCTP_DISPOSITION_CONSUME;
 
+nomem_authev:
+        sctp_ulpevent_free(ai_ev);
 nomem_aiev:
         sctp_ulpevent_free(ev);
 nomem_ev:
@@ -953,6 +967,15 @@ enum sctp_disposition sctp_sf_do_5_1E_ca(struct net *net,
                                 SCTP_ULPEVENT(ev));
         }
 
+        if (!asoc->peer.auth_capable) {
+                ev = sctp_ulpevent_make_authkey(asoc, 0, SCTP_AUTH_NO_AUTH,
+                                                GFP_ATOMIC);
+                if (!ev)
+                        goto nomem;
+                sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
+                                SCTP_ULPEVENT(ev));
+        }
+
         return SCTP_DISPOSITION_CONSUME;
 nomem:
         return SCTP_DISPOSITION_NOMEM;
@@ -1908,6 +1931,9 @@ static enum sctp_disposition sctp_sf_do_dupcook_b(
         if (asoc->peer.adaptation_ind)
                 sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());
 
+        if (!asoc->peer.auth_capable)
+                sctp_add_cmd_sf(commands, SCTP_CMD_PEER_NO_AUTH, SCTP_NULL());
+
         return SCTP_DISPOSITION_CONSUME;
 
 nomem:
@@ -1954,7 +1980,7 @@ static enum sctp_disposition sctp_sf_do_dupcook_d(
                                         struct sctp_cmd_seq *commands,
                                         struct sctp_association *new_asoc)
 {
-        struct sctp_ulpevent *ev = NULL, *ai_ev = NULL;
+        struct sctp_ulpevent *ev = NULL, *ai_ev = NULL, *auth_ev = NULL;
         struct sctp_chunk *repl;
 
         /* Clarification from Implementor's Guide:
@@ -2001,6 +2027,14 @@ static enum sctp_disposition sctp_sf_do_dupcook_d(
                                 goto nomem;
 
                 }
+
+                if (!asoc->peer.auth_capable) {
+                        auth_ev = sctp_ulpevent_make_authkey(asoc, 0,
+                                                             SCTP_AUTH_NO_AUTH,
+                                                             GFP_ATOMIC);
+                        if (!auth_ev)
+                                goto nomem;
+                }
         }
 
         repl = sctp_make_cookie_ack(new_asoc, chunk);
@@ -2015,10 +2049,15 @@ static enum sctp_disposition sctp_sf_do_dupcook_d(
         if (ai_ev)
                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
                                         SCTP_ULPEVENT(ai_ev));
+        if (auth_ev)
+                sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
+                                SCTP_ULPEVENT(auth_ev));
 
         return SCTP_DISPOSITION_CONSUME;
 
 nomem:
+        if (auth_ev)
+                sctp_ulpevent_free(auth_ev);
         if (ai_ev)
                 sctp_ulpevent_free(ai_ev);
         if (ev)