summaryrefslogtreecommitdiffstats
path: root/net/sctp
diff options
context:
space:
mode:
Diffstat (limited to 'net/sctp')
-rw-r--r--net/sctp/associola.c10
-rw-r--r--net/sctp/endpointola.c29
-rw-r--r--net/sctp/input.c65
-rw-r--r--net/sctp/inqueue.c19
-rw-r--r--net/sctp/sm_statefuns.c218
-rw-r--r--net/sctp/sm_statetable.c33
6 files changed, 362 insertions, 12 deletions
diff --git a/net/sctp/associola.c b/net/sctp/associola.c
index 3bdd8dcb76a..03158e3665d 100644
--- a/net/sctp/associola.c
+++ b/net/sctp/associola.c
@@ -1011,6 +1011,16 @@ static void sctp_assoc_bh_rcv(struct work_struct *work)
state = asoc->state;
subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
+ /* SCTP-AUTH, Section 6.3:
+ * The receiver has a list of chunk types which it expects
+ * to be received only after an AUTH-chunk. This list has
+ * been sent to the peer during the association setup. It
+ * MUST silently discard these chunks if they are not placed
+ * after an AUTH chunk in the packet.
+ */
+ if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth)
+ continue;
+
/* Remember where the last DATA chunk came from so we
* know where to send the SACK.
*/
diff --git a/net/sctp/endpointola.c b/net/sctp/endpointola.c
index c8d5023606a..2d2d81ef4a6 100644
--- a/net/sctp/endpointola.c
+++ b/net/sctp/endpointola.c
@@ -400,6 +400,7 @@ static void sctp_endpoint_bh_rcv(struct work_struct *work)
sctp_subtype_t subtype;
sctp_state_t state;
int error = 0;
+ int first_time = 1; /* is this the first time through the looop */
if (ep->base.dead)
return;
@@ -411,6 +412,29 @@ static void sctp_endpoint_bh_rcv(struct work_struct *work)
while (NULL != (chunk = sctp_inq_pop(inqueue))) {
subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
+ /* If the first chunk in the packet is AUTH, do special
+ * processing specified in Section 6.3 of SCTP-AUTH spec
+ */
+ if (first_time && (subtype.chunk == SCTP_CID_AUTH)) {
+ struct sctp_chunkhdr *next_hdr;
+
+ next_hdr = sctp_inq_peek(inqueue);
+ if (!next_hdr)
+ goto normal;
+
+ /* If the next chunk is COOKIE-ECHO, skip the AUTH
+ * chunk while saving a pointer to it so we can do
+ * Authentication later (during cookie-echo
+ * processing).
+ */
+ if (next_hdr->type == SCTP_CID_COOKIE_ECHO) {
+ chunk->auth_chunk = skb_clone(chunk->skb,
+ GFP_ATOMIC);
+ chunk->auth = 1;
+ continue;
+ }
+ }
+normal:
/* We might have grown an association since last we
* looked, so try again.
*
@@ -426,6 +450,8 @@ static void sctp_endpoint_bh_rcv(struct work_struct *work)
}
state = asoc ? asoc->state : SCTP_STATE_CLOSED;
+ if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth)
+ continue;
/* Remember where the last DATA chunk came from so we
* know where to send the SACK.
@@ -449,5 +475,8 @@ static void sctp_endpoint_bh_rcv(struct work_struct *work)
*/
if (!sctp_sk(sk)->ep)
break;
+
+ if (first_time)
+ first_time = 0;
}
}
diff --git a/net/sctp/input.c b/net/sctp/input.c
index f9a0c9276e3..86503e7fa21 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -911,15 +911,6 @@ static struct sctp_association *__sctp_rcv_init_lookup(struct sk_buff *skb,
ch = (sctp_chunkhdr_t *) skb->data;
- /* If this is INIT/INIT-ACK look inside the chunk too. */
- switch (ch->type) {
- case SCTP_CID_INIT:
- case SCTP_CID_INIT_ACK:
- break;
- default:
- return NULL;
- }
-
/* The code below will attempt to walk the chunk and extract
* parameter information. Before we do that, we need to verify
* that the chunk length doesn't cause overflow. Otherwise, we'll
@@ -964,6 +955,60 @@ static struct sctp_association *__sctp_rcv_init_lookup(struct sk_buff *skb,
return NULL;
}
+/* SCTP-AUTH, Section 6.3:
+* If the receiver does not find a STCB for a packet containing an AUTH
+* chunk as the first chunk and not a COOKIE-ECHO chunk as the second
+* chunk, it MUST use the chunks after the AUTH chunk to look up an existing
+* association.
+*
+* This means that any chunks that can help us identify the association need
+* to be looked at to find this assocation.
+*
+* TODO: The only chunk currently defined that can do that is ASCONF, but we
+* don't support that functionality yet.
+*/
+static struct sctp_association *__sctp_rcv_auth_lookup(struct sk_buff *skb,
+ const union sctp_addr *paddr,
+ const union sctp_addr *laddr,
+ struct sctp_transport **transportp)
+{
+ /* XXX - walk through the chunks looking for something that can
+ * help us find the association. INIT, and INIT-ACK are not permitted.
+ * That leaves ASCONF, but we don't support that yet.
+ */
+ return NULL;
+}
+
+/*
+ * There are circumstances when we need to look inside the SCTP packet
+ * for information to help us find the association. Examples
+ * include looking inside of INIT/INIT-ACK chunks or after the AUTH
+ * chunks.
+ */
+static struct sctp_association *__sctp_rcv_lookup_harder(struct sk_buff *skb,
+ const union sctp_addr *paddr,
+ const union sctp_addr *laddr,
+ struct sctp_transport **transportp)
+{
+ sctp_chunkhdr_t *ch;
+
+ ch = (sctp_chunkhdr_t *) skb->data;
+
+ /* If this is INIT/INIT-ACK look inside the chunk too. */
+ switch (ch->type) {
+ case SCTP_CID_INIT:
+ case SCTP_CID_INIT_ACK:
+ return __sctp_rcv_init_lookup(skb, laddr, transportp);
+ break;
+
+ case SCTP_CID_AUTH:
+ return __sctp_rcv_auth_lookup(skb, paddr, laddr, transportp);
+ break;
+ }
+
+ return NULL;
+}
+
/* Lookup an association for an inbound skb. */
static struct sctp_association *__sctp_rcv_lookup(struct sk_buff *skb,
const union sctp_addr *paddr,
@@ -979,7 +1024,7 @@ static struct sctp_association *__sctp_rcv_lookup(struct sk_buff *skb,
* parameters within the INIT or INIT-ACK.
*/
if (!asoc)
- asoc = __sctp_rcv_init_lookup(skb, laddr, transportp);
+ asoc = __sctp_rcv_lookup_harder(skb, paddr, laddr, transportp);
return asoc;
}
diff --git a/net/sctp/inqueue.c b/net/sctp/inqueue.c
index e4ea7fdf36e..f10fe7fbf24 100644
--- a/net/sctp/inqueue.c
+++ b/net/sctp/inqueue.c
@@ -100,6 +100,25 @@ void sctp_inq_push(struct sctp_inq *q, struct sctp_chunk *chunk)
q->immediate.func(&q->immediate);
}
+/* Peek at the next chunk on the inqeue. */
+struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *queue)
+{
+ struct sctp_chunk *chunk;
+ sctp_chunkhdr_t *ch = NULL;
+
+ chunk = queue->in_progress;
+ /* If there is no more chunks in this packet, say so */
+ if (chunk->singleton ||
+ chunk->end_of_packet ||
+ chunk->pdiscard)
+ return NULL;
+
+ ch = (sctp_chunkhdr_t *)chunk->chunk_end;
+
+ return ch;
+}
+
+
/* Extract a chunk from an SCTP inqueue.
*
* WARNING: If you need to put the chunk on another queue, you need to
diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index 385486360fe..5aef4aafdfd 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -138,6 +138,11 @@ static sctp_disposition_t sctp_sf_violation_chunk(
void *arg,
sctp_cmd_seq_t *commands);
+static sctp_ierror_t sctp_sf_authenticate(const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ struct sctp_chunk *chunk);
+
/* Small helper function that checks if the chunk length
* is of the appropriate length. The 'required_length' argument
* is set to be the size of a specific chunk we are testing.
@@ -495,8 +500,6 @@ sctp_disposition_t sctp_sf_do_5_1C_ack(const struct sctp_endpoint *ep,
(sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
&err_chunk)) {
- SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
-
/* This chunk contains fatal error. It is to be discarded.
* Send an ABORT, with causes if there is any.
*/
@@ -521,6 +524,22 @@ sctp_disposition_t sctp_sf_do_5_1C_ack(const struct sctp_endpoint *ep,
sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
error = SCTP_ERROR_INV_PARAM;
}
+
+ /* SCTP-AUTH, Section 6.3:
+ * It should be noted that if the receiver wants to tear
+ * down an association in an authenticated way only, the
+ * handling of malformed packets should not result in
+ * tearing down the association.
+ *
+ * This means that if we only want to abort associations
+ * in an authenticated way (i.e AUTH+ABORT), then we
+ * can't destory this association just becuase the packet
+ * was malformed.
+ */
+ if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
+ return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+
+ SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED,
asoc, chunk->transport);
}
@@ -699,6 +718,36 @@ sctp_disposition_t sctp_sf_do_5_1D_ce(const struct sctp_endpoint *ep,
if (error)
goto nomem_init;
+ /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
+ * is supposed to be authenticated and we have to do delayed
+ * authentication. We've just recreated the association using
+ * the information in the cookie and now it's much easier to
+ * do the authentication.
+ */
+ if (chunk->auth_chunk) {
+ struct sctp_chunk auth;
+ sctp_ierror_t ret;
+
+ /* set-up our fake chunk so that we can process it */
+ auth.skb = chunk->auth_chunk;
+ auth.asoc = chunk->asoc;
+ auth.sctp_hdr = chunk->sctp_hdr;
+ auth.chunk_hdr = (sctp_chunkhdr_t *)skb_push(chunk->auth_chunk,
+ sizeof(sctp_chunkhdr_t));
+ skb_pull(chunk->auth_chunk, sizeof(sctp_chunkhdr_t));
+ auth.transport = chunk->transport;
+
+ ret = sctp_sf_authenticate(ep, new_asoc, type, &auth);
+
+ /* We can now safely free the auth_chunk clone */
+ kfree_skb(chunk->auth_chunk);
+
+ if (ret != SCTP_IERROR_NO_ERROR) {
+ sctp_association_free(new_asoc);
+ return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+ }
+ }
+
repl = sctp_make_cookie_ack(new_asoc, chunk);
if (!repl)
goto nomem_init;
@@ -3653,6 +3702,156 @@ gen_shutdown:
}
/*
+ * SCTP-AUTH Section 6.3 Receving authenticated chukns
+ *
+ * The receiver MUST use the HMAC algorithm indicated in the HMAC
+ * Identifier field. If this algorithm was not specified by the
+ * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
+ * during association setup, the AUTH chunk and all chunks after it MUST
+ * be discarded and an ERROR chunk SHOULD be sent with the error cause
+ * defined in Section 4.1.
+ *
+ * If an endpoint with no shared key receives a Shared Key Identifier
+ * other than 0, it MUST silently discard all authenticated chunks. If
+ * the endpoint has at least one endpoint pair shared key for the peer,
+ * it MUST use the key specified by the Shared Key Identifier if a
+ * key has been configured for that Shared Key Identifier. If no
+ * endpoint pair shared key has been configured for that Shared Key
+ * Identifier, all authenticated chunks MUST be silently discarded.
+ *
+ * Verification Tag: 8.5 Verification Tag [Normal verification]
+ *
+ * The return value is the disposition of the chunk.
+ */
+static sctp_ierror_t sctp_sf_authenticate(const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ struct sctp_chunk *chunk)
+{
+ struct sctp_authhdr *auth_hdr;
+ struct sctp_hmac *hmac;
+ unsigned int sig_len;
+ __u16 key_id;
+ __u8 *save_digest;
+ __u8 *digest;
+
+ /* Pull in the auth header, so we can do some more verification */
+ auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
+ chunk->subh.auth_hdr = auth_hdr;
+ skb_pull(chunk->skb, sizeof(struct sctp_authhdr));
+
+ /* Make sure that we suport the HMAC algorithm from the auth
+ * chunk.
+ */
+ if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id))
+ return SCTP_IERROR_AUTH_BAD_HMAC;
+
+ /* Make sure that the provided shared key identifier has been
+ * configured
+ */
+ key_id = ntohs(auth_hdr->shkey_id);
+ if (key_id != asoc->active_key_id && !sctp_auth_get_shkey(asoc, key_id))
+ return SCTP_IERROR_AUTH_BAD_KEYID;
+
+
+ /* Make sure that the length of the signature matches what
+ * we expect.
+ */
+ sig_len = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_auth_chunk_t);
+ hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id));
+ if (sig_len != hmac->hmac_len)
+ return SCTP_IERROR_PROTO_VIOLATION;
+
+ /* Now that we've done validation checks, we can compute and
+ * verify the hmac. The steps involved are:
+ * 1. Save the digest from the chunk.
+ * 2. Zero out the digest in the chunk.
+ * 3. Compute the new digest
+ * 4. Compare saved and new digests.
+ */
+ digest = auth_hdr->hmac;
+ skb_pull(chunk->skb, sig_len);
+
+ save_digest = kmemdup(digest, sig_len, GFP_ATOMIC);
+ if (!save_digest)
+ goto nomem;
+
+ memset(digest, 0, sig_len);
+
+ sctp_auth_calculate_hmac(asoc, chunk->skb,
+ (struct sctp_auth_chunk *)chunk->chunk_hdr,
+ GFP_ATOMIC);
+
+ /* Discard the packet if the digests do not match */
+ if (memcmp(save_digest, digest, sig_len)) {
+ kfree(save_digest);
+ return SCTP_IERROR_BAD_SIG;
+ }
+
+ kfree(save_digest);
+ chunk->auth = 1;
+
+ return SCTP_IERROR_NO_ERROR;
+nomem:
+ return SCTP_IERROR_NOMEM;
+}
+
+sctp_disposition_t sctp_sf_eat_auth(const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_authhdr *auth_hdr;
+ struct sctp_chunk *chunk = arg;
+ struct sctp_chunk *err_chunk;
+ sctp_ierror_t error;
+
+ if (!sctp_vtag_verify(chunk, asoc)) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
+ SCTP_NULL());
+ return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+ }
+
+ /* Make sure that the AUTH chunk has valid length. */
+ if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk)))
+ return sctp_sf_violation_chunklen(ep, asoc, type, arg,
+ commands);
+
+ auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
+ error = sctp_sf_authenticate(ep, asoc, type, chunk);
+ switch (error) {
+ case SCTP_IERROR_AUTH_BAD_HMAC:
+ /* Generate the ERROR chunk and discard the rest
+ * of the packet
+ */
+ err_chunk = sctp_make_op_error(asoc, chunk,
+ SCTP_ERROR_UNSUP_HMAC,
+ &auth_hdr->hmac_id,
+ sizeof(__u16));
+ if (err_chunk) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
+ SCTP_CHUNK(err_chunk));
+ }
+ /* Fall Through */
+ case SCTP_IERROR_AUTH_BAD_KEYID:
+ case SCTP_IERROR_BAD_SIG:
+ return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+ break;
+ case SCTP_IERROR_PROTO_VIOLATION:
+ return sctp_sf_violation_chunklen(ep, asoc, type, arg,
+ commands);
+ break;
+ case SCTP_IERROR_NOMEM:
+ return SCTP_DISPOSITION_NOMEM;
+ default:
+ break;
+ }
+
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/*
* Process an unknown chunk.
*
* Section: 3.2. Also, 2.1 in the implementor's guide.
@@ -3857,6 +4056,20 @@ static sctp_disposition_t sctp_sf_abort_violation(
if (!abort)
goto nomem;
+ /* SCTP-AUTH, Section 6.3:
+ * It should be noted that if the receiver wants to tear
+ * down an association in an authenticated way only, the
+ * handling of malformed packets should not result in
+ * tearing down the association.
+ *
+ * This means that if we only want to abort associations
+ * in an authenticated way (i.e AUTH+ABORT), then we
+ * can't destory this association just becuase the packet
+ * was malformed.
+ */
+ if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
+ goto discard;
+
if (asoc) {
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
@@ -3894,6 +4107,7 @@ static sctp_disposition_t sctp_sf_abort_violation(
SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
}
+discard:
sctp_sf_pdiscard(ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
diff --git a/net/sctp/sm_statetable.c b/net/sctp/sm_statetable.c
index ddb0ba3974b..a93a4bc8f68 100644
--- a/net/sctp/sm_statetable.c
+++ b/net/sctp/sm_statetable.c
@@ -523,6 +523,34 @@ static const sctp_sm_table_entry_t prsctp_chunk_event_table[SCTP_NUM_PRSCTP_CHUN
TYPE_SCTP_FWD_TSN,
}; /*state_fn_t prsctp_chunk_event_table[][] */
+#define TYPE_SCTP_AUTH { \
+ /* SCTP_STATE_EMPTY */ \
+ TYPE_SCTP_FUNC(sctp_sf_ootb), \
+ /* SCTP_STATE_CLOSED */ \
+ TYPE_SCTP_FUNC(sctp_sf_ootb), \
+ /* SCTP_STATE_COOKIE_WAIT */ \
+ TYPE_SCTP_FUNC(sctp_sf_discard_chunk), \
+ /* SCTP_STATE_COOKIE_ECHOED */ \
+ TYPE_SCTP_FUNC(sctp_sf_eat_auth), \
+ /* SCTP_STATE_ESTABLISHED */ \
+ TYPE_SCTP_FUNC(sctp_sf_eat_auth), \
+ /* SCTP_STATE_SHUTDOWN_PENDING */ \
+ TYPE_SCTP_FUNC(sctp_sf_eat_auth), \
+ /* SCTP_STATE_SHUTDOWN_SENT */ \
+ TYPE_SCTP_FUNC(sctp_sf_eat_auth), \
+ /* SCTP_STATE_SHUTDOWN_RECEIVED */ \
+ TYPE_SCTP_FUNC(sctp_sf_eat_auth), \
+ /* SCTP_STATE_SHUTDOWN_ACK_SENT */ \
+ TYPE_SCTP_FUNC(sctp_sf_eat_auth), \
+} /* TYPE_SCTP_AUTH */
+
+/* The primary index for this table is the chunk type.
+ * The secondary index for this table is the state.
+ */
+static const sctp_sm_table_entry_t auth_chunk_event_table[SCTP_NUM_AUTH_CHUNK_TYPES][SCTP_STATE_NUM_STATES] = {
+ TYPE_SCTP_AUTH,
+}; /*state_fn_t auth_chunk_event_table[][] */
+
static const sctp_sm_table_entry_t
chunk_event_table_unknown[SCTP_STATE_NUM_STATES] = {
/* SCTP_STATE_EMPTY */
@@ -976,5 +1004,10 @@ static const sctp_sm_table_entry_t *sctp_chunk_event_lookup(sctp_cid_t cid,
return &addip_chunk_event_table[1][state];
}
+ if (sctp_auth_enable) {
+ if (cid == SCTP_CID_AUTH)
+ return &auth_chunk_event_table[0][state];
+ }
+
return &chunk_event_table_unknown[state];
}