SCTP: Make sctp_verify_param return multiple indications.

SCTP-AUTH and future ADD-IP updates have a requirement to
do additional verification of parameters and an ability to
ABORT the association if verification fails.  So, introduce
additional return code so that we can clear signal a required
action.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

diff --git a/include/net/sctp/constants.h b/include/net/sctp/constants.h
index 73fbdf6..f30b537 100644 (file)
--- a/include/net/sctp/constants.h
+++ b/include/net/sctp/constants.h
@@ -186,6 +186,8 @@ typedef enum {
        SCTP_IERROR_AUTH_BAD_HMAC,
        SCTP_IERROR_AUTH_BAD_KEYID,
        SCTP_IERROR_PROTO_VIOLATION,
+       SCTP_IERROR_ERROR,
+       SCTP_IERROR_ABORT,
 } sctp_ierror_t;
 
 

diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index 43e8de1..5a9783c 100644 (file)
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -1788,9 +1788,14 @@ static int sctp_process_inv_paramlength(const struct sctp_association *asoc,
                                                sizeof(sctp_paramhdr_t);
 
 
+       /* This is a fatal error.  Any accumulated non-fatal errors are
+        * not reported.
+        */
+       if (*errp)
+               sctp_chunk_free(*errp);
+
        /* Create an error chunk and fill it in with our payload. */
-       if (!*errp)
-               *errp = sctp_make_op_error_space(asoc, chunk, payload_len);
+       *errp = sctp_make_op_error_space(asoc, chunk, payload_len);
 
        if (*errp) {
                sctp_init_cause(*errp, SCTP_ERROR_PROTO_VIOLATION,
@@ -1813,9 +1818,15 @@ static int sctp_process_hn_param(const struct sctp_association *asoc,
 {
        __u16 len = ntohs(param.p->length);
 
-       /* Make an ERROR chunk. */
-       if (!*errp)
-               *errp = sctp_make_op_error_space(asoc, chunk, len);
+       /* Processing of the HOST_NAME parameter will generate an
+        * ABORT.  If we've accumulated any non-fatal errors, they
+        * would be unrecognized parameters and we should not include
+        * them in the ABORT.
+        */
+       if (*errp)
+               sctp_chunk_free(*errp);
+
+       *errp = sctp_make_op_error_space(asoc, chunk, len);
 
        if (*errp) {
                sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len);
@@ -1862,56 +1873,40 @@ static void sctp_process_ext_param(struct sctp_association *asoc,
  * taken if the processing endpoint does not recognize the
  * Parameter Type.
  *
- * 00 - Stop processing this SCTP chunk and discard it,
- *     do not process any further chunks within it.
+ * 00 - Stop processing this parameter; do not process any further
+ *     parameters within this chunk
  *
- * 01 - Stop processing this SCTP chunk and discard it,
- *     do not process any further chunks within it, and report
- *     the unrecognized parameter in an 'Unrecognized
- *     Parameter Type' (in either an ERROR or in the INIT ACK).
+ * 01 - Stop processing this parameter, do not process any further
+ *     parameters within this chunk, and report the unrecognized
+ *     parameter in an 'Unrecognized Parameter' ERROR chunk.
  *
  * 10 - Skip this parameter and continue processing.
  *
  * 11 - Skip this parameter and continue processing but
  *     report the unrecognized parameter in an
- *     'Unrecognized Parameter Type' (in either an ERROR or in
- *     the INIT ACK).
+ *     'Unrecognized Parameter' ERROR chunk.
  *
  * Return value:
- *     0 - discard the chunk
- *     1 - continue with the chunk
+ *     SCTP_IERROR_NO_ERROR - continue with the chunk
+ *     SCTP_IERROR_ERROR    - stop and report an error.
+ *     SCTP_IERROR_NOMEME   - out of memory.
  */
-static int sctp_process_unk_param(const struct sctp_association *asoc,
-                                 union sctp_params param,
-                                 struct sctp_chunk *chunk,
-                                 struct sctp_chunk **errp)
+static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc,
+                                           union sctp_params param,
+                                           struct sctp_chunk *chunk,
+                                           struct sctp_chunk **errp)
 {
-       int retval = 1;
+       int retval = SCTP_IERROR_NO_ERROR;
 
        switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
        case SCTP_PARAM_ACTION_DISCARD:
-               retval =  0;
-               break;
-       case SCTP_PARAM_ACTION_DISCARD_ERR:
-               retval =  0;
-               /* Make an ERROR chunk, preparing enough room for
-                * returning multiple unknown parameters.
-                */
-               if (NULL == *errp)
-                       *errp = sctp_make_op_error_space(asoc, chunk,
-                                       ntohs(chunk->chunk_hdr->length));
-
-               if (*errp) {
-                       sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM,
-                                       WORD_ROUND(ntohs(param.p->length)));
-                       sctp_addto_chunk(*errp,
-                                       WORD_ROUND(ntohs(param.p->length)),
-                                       param.v);
-               }
-
+               retval =  SCTP_IERROR_ERROR;
                break;
        case SCTP_PARAM_ACTION_SKIP:
                break;
+       case SCTP_PARAM_ACTION_DISCARD_ERR:
+               retval =  SCTP_IERROR_ERROR;
+               /* Fall through */
        case SCTP_PARAM_ACTION_SKIP_ERR:
                /* Make an ERROR chunk, preparing enough room for
                 * returning multiple unknown parameters.
@@ -1932,9 +1927,8 @@ static int sctp_process_unk_param(const struct sctp_association *asoc,
                         * to the peer and the association won't be
                         * established.
                         */
-                       retval = 0;
+                       retval = SCTP_IERROR_NOMEM;
                }
-
                break;
        default:
                break;
@@ -1943,18 +1937,20 @@ static int sctp_process_unk_param(const struct sctp_association *asoc,
        return retval;
 }
 
-/* Find unrecognized parameters in the chunk.
+/* Verify variable length parameters
  * Return values:
- *     0 - discard the chunk
- *     1 - continue with the chunk
+ *     SCTP_IERROR_ABORT - trigger an ABORT
+ *     SCTP_IERROR_NOMEM - out of memory (abort)
+ *     SCTP_IERROR_ERROR - stop processing, trigger an ERROR
+ *     SCTP_IERROR_NO_ERROR - continue with the chunk
  */
-static int sctp_verify_param(const struct sctp_association *asoc,
-                            union sctp_params param,
-                            sctp_cid_t cid,
-                            struct sctp_chunk *chunk,
-                            struct sctp_chunk **err_chunk)
+static sctp_ierror_t sctp_verify_param(const struct sctp_association *asoc,
+                                       union sctp_params param,
+                                       sctp_cid_t cid,
+                                       struct sctp_chunk *chunk,
+                                       struct sctp_chunk **err_chunk)
 {
-       int retval = 1;
+       int retval = SCTP_IERROR_NO_ERROR;
 
        /* FIXME - This routine is not looking at each parameter per the
         * chunk type, i.e., unrecognized parameters should be further
@@ -1976,7 +1972,9 @@ static int sctp_verify_param(const struct sctp_association *asoc,
 
        case SCTP_PARAM_HOST_NAME_ADDRESS:
                /* Tell the peer, we won't support this param.  */
-               return sctp_process_hn_param(asoc, param, chunk, err_chunk);
+               sctp_process_hn_param(asoc, param, chunk, err_chunk);
+               retval = SCTP_IERROR_ABORT;
+               break;
 
        case SCTP_PARAM_FWD_TSN_SUPPORT:
                if (sctp_prsctp_enable)
@@ -1993,9 +1991,11 @@ static int sctp_verify_param(const struct sctp_association *asoc,
                 * cause 'Protocol Violation'.
                 */
                if (SCTP_AUTH_RANDOM_LENGTH !=
-                       ntohs(param.p->length) - sizeof(sctp_paramhdr_t))
-                       return sctp_process_inv_paramlength(asoc, param.p,
+                       ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) {
+                       sctp_process_inv_paramlength(asoc, param.p,
                                                        chunk, err_chunk);
+                       retval = SCTP_IERROR_ABORT;
+               }
                break;
 
        case SCTP_PARAM_CHUNKS:
@@ -2007,9 +2007,11 @@ static int sctp_verify_param(const struct sctp_association *asoc,
                 *  INIT-ACK chunk if the sender wants to receive authenticated
                 *  chunks.  Its maximum length is 260 bytes.
                 */
-               if (260 < ntohs(param.p->length))
-                       return sctp_process_inv_paramlength(asoc, param.p,
-                                                       chunk, err_chunk);
+               if (260 < ntohs(param.p->length)) {
+                       sctp_process_inv_paramlength(asoc, param.p,
+                                                    chunk, err_chunk);
+                       retval = SCTP_IERROR_ABORT;
+               }
                break;
 
        case SCTP_PARAM_HMAC_ALGO:
@@ -2020,8 +2022,7 @@ fallthrough:
        default:
                SCTP_DEBUG_PRINTK("Unrecognized param: %d for chunk %d.\n",
                                ntohs(param.p->type), cid);
-               return sctp_process_unk_param(asoc, param, chunk, err_chunk);
-
+               retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
                break;
        }
        return retval;
@@ -2036,6 +2037,7 @@ int sctp_verify_init(const struct sctp_association *asoc,
 {
        union sctp_params param;
        int has_cookie = 0;
+       int result;
 
        /* Verify stream values are non-zero. */
        if ((0 == peer_init->init_hdr.num_outbound_streams) ||
@@ -2043,8 +2045,7 @@ int sctp_verify_init(const struct sctp_association *asoc,
            (0 == peer_init->init_hdr.init_tag) ||
            (SCTP_DEFAULT_MINWINDOW > ntohl(peer_init->init_hdr.a_rwnd))) {
 
-               sctp_process_inv_mandatory(asoc, chunk, errp);
-               return 0;
+               return sctp_process_inv_mandatory(asoc, chunk, errp);
        }
 
        /* Check for missing mandatory parameters.  */
@@ -2062,29 +2063,29 @@ int sctp_verify_init(const struct sctp_association *asoc,
         * VIOLATION error.  We build the ERROR chunk here and let the normal
         * error handling code build and send the packet.
         */
-       if (param.v != (void*)chunk->chunk_end) {
-               sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
-               return 0;
-       }
+       if (param.v != (void*)chunk->chunk_end)
+               return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
 
        /* The only missing mandatory param possible today is
         * the state cookie for an INIT-ACK chunk.
         */
-       if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) {
-               sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
-                                          chunk, errp);
-               return 0;
-       }
-
-       /* Find unrecognized parameters. */
+       if ((SCTP_CID_INIT_ACK == cid) && !has_cookie)
+               return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
+                                                 chunk, errp);
 
+       /* Verify all the variable length parameters */
        sctp_walk_params(param, peer_init, init_hdr.params) {
 
-               if (!sctp_verify_param(asoc, param, cid, chunk, errp)) {
-                       if (SCTP_PARAM_HOST_NAME_ADDRESS == param.p->type)
+               result = sctp_verify_param(asoc, param, cid, chunk, errp);
+               switch (result) {
+                   case SCTP_IERROR_ABORT:
+                   case SCTP_IERROR_NOMEM:
                                return 0;
-                       else
+                   case SCTP_IERROR_ERROR:
                                return 1;
+                   case SCTP_IERROR_NO_ERROR:
+                   default:
+                               break;
                }
 
        } /* for (loop through all parameters) */