diff options
| author | Xin Long <lucien.xin@gmail.com> | 2021-06-22 14:04:47 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-06-22 11:28:51 -0700 |
| commit | 745a32117b5a0799ce1dd28d5a74dc2b7bf37692 (patch) | |
| tree | 5185d120079012222b201155fc27b596c94ccbf2 /net/sctp | |
| parent | aff0824dc4d6ef5ee164c0e98e64d91731ca585b (diff) | |
sctp: add pad chunk and its make function and event table
This chunk is defined in rfc4820#section-3, and used to pad an
SCTP packet. The receiver must discard this chunk and continue
processing the rest of the chunks in the packet.
Add it now, as it will be bundled with a heartbeat chunk to probe
pmtu in the following patches.
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>
Diffstat (limited to 'net/sctp')
| -rw-r--r-- | net/sctp/sm_make_chunk.c | 26 | ||||
| -rw-r--r-- | net/sctp/sm_statetable.c | 23 |
2 files changed, 49 insertions, 0 deletions
diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c index 5b44d228b6ca..e5d470cd7c40 100644 --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c @@ -1218,6 +1218,32 @@ nodata: return retval; } +/* RFC4820 3. Padding Chunk (PAD) + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Type = 0x84 | Flags=0 | Length | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | | + * \ Padding Data / + * / \ + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + */ +struct sctp_chunk *sctp_make_pad(const struct sctp_association *asoc, int len) +{ + struct sctp_chunk *retval; + + retval = sctp_make_control(asoc, SCTP_CID_PAD, 0, len, GFP_ATOMIC); + if (!retval) + return NULL; + + skb_put_zero(retval->skb, len); + retval->chunk_hdr->length = htons(ntohs(retval->chunk_hdr->length) + len); + retval->chunk_end = skb_tail_pointer(retval->skb); + + return retval; +} + /* Create an Operation Error chunk with the specified space reserved. * This routine can be used for containing multiple causes in the chunk. */ diff --git a/net/sctp/sm_statetable.c b/net/sctp/sm_statetable.c index 88ea87f4f0e7..c82c4233ec6b 100644 --- a/net/sctp/sm_statetable.c +++ b/net/sctp/sm_statetable.c @@ -527,6 +527,26 @@ auth_chunk_event_table[SCTP_NUM_AUTH_CHUNK_TYPES][SCTP_STATE_NUM_STATES] = { }; /*state_fn_t auth_chunk_event_table[][] */ static const struct sctp_sm_table_entry +pad_chunk_event_table[SCTP_STATE_NUM_STATES] = { + /* SCTP_STATE_CLOSED */ + TYPE_SCTP_FUNC(sctp_sf_discard_chunk), + /* SCTP_STATE_COOKIE_WAIT */ + TYPE_SCTP_FUNC(sctp_sf_discard_chunk), + /* SCTP_STATE_COOKIE_ECHOED */ + TYPE_SCTP_FUNC(sctp_sf_discard_chunk), + /* SCTP_STATE_ESTABLISHED */ + TYPE_SCTP_FUNC(sctp_sf_discard_chunk), + /* SCTP_STATE_SHUTDOWN_PENDING */ + TYPE_SCTP_FUNC(sctp_sf_discard_chunk), + /* SCTP_STATE_SHUTDOWN_SENT */ + TYPE_SCTP_FUNC(sctp_sf_discard_chunk), + /* SCTP_STATE_SHUTDOWN_RECEIVED */ + TYPE_SCTP_FUNC(sctp_sf_discard_chunk), + /* SCTP_STATE_SHUTDOWN_ACK_SENT */ + TYPE_SCTP_FUNC(sctp_sf_discard_chunk), +}; /* chunk pad */ + +static const struct sctp_sm_table_entry chunk_event_table_unknown[SCTP_STATE_NUM_STATES] = { /* SCTP_STATE_CLOSED */ TYPE_SCTP_FUNC(sctp_sf_ootb), @@ -992,6 +1012,9 @@ static const struct sctp_sm_table_entry *sctp_chunk_event_lookup( case SCTP_CID_AUTH: return &auth_chunk_event_table[0][state]; + + case SCTP_CID_PAD: + return &pad_chunk_event_table[state]; } return &chunk_event_table_unknown[state]; |