Allow injected COOKIE_ECHO chunks to be bundled with other chunks.

This fixes https://github.com/nplab/packetdrill/issues/1

gtests/net/packetdrill/run_packet.c

@@ -2154,8 +2154,11 @@ static int do_inbound_script_packet(
 		if (socket->state == SOCKET_PASSIVE_INIT_ACK_SENT) {
 			for (; item != NULL; item = item->next) {
 				if (item->chunk->type == SCTP_COOKIE_ECHO_CHUNK_TYPE) {
-					assert(item->next == NULL); /*FIXME: Handle chunks after the COOKIE_ECHO */
 					offset = socket->prepared_state_cookie_length - item->length;
+					assert(packet->ip_bytes + offset <= packet->buffer_bytes);
+					memmove((u8 *)item->chunk + item->length + offset,
+					        (u8 *)item->chunk + item->length,
+					        packet_end(packet) - ((u8 *)item->chunk + item->length));
 					memcpy(item->chunk, socket->prepared_state_cookie, socket->prepared_state_cookie_length);
 					item->length = socket->prepared_state_cookie_length;
 					packet->buffer_bytes += offset;

gtests/net/packetdrill/tests/bsd/sctp/sctp_passive.pkt

@@ -4,21 +4,22 @@
 +0.0 listen(3, 1) = 0
 +0.0 < sctp: INIT[tag=1 a_rwnd=1500 os=1 is=1 tsn=0]
 +0.0 > sctp: INIT_ACK[tag=2 tsn=10] // faked cookie
-+0.1 < sctp: COOKIE_ECHO[] // syntax not clear
-+0.0 > sctp: COOKIE_ACK[]
++0.1 < sctp: COOKIE_ECHO[]; DATA[tsn=0 sid=0 ssn=0 ppid=0]// syntax not clear
++0.0 > sctp: COOKIE_ACK[]; SACK[tsn=0]
 +0.0 accept(3, ..., ...) = 4
++0.0 read(4, ..., 1000) = 1000
 // Send some data.
 +1.0 write(4, ..., 1000) = 1000
 +0.0 > sctp: DATA[tsn=10 sid=0 ssn=0 ppid=0]
 +0.1 < sctp: SACK[tsn=10 a_rwnd=1500]
 // Receive some data
-+1.0 < sctp: DATA[tsn=0 sid=0 ssn=0 ppid=0] // How to handle payload?
++1.0 < sctp: DATA[tsn=1 sid=0 ssn=1 ppid=0] // How to handle payload?
 +0.0 read(4, ..., 2000) = 1000
-+0.0 > sctp: SACK[tsn=0]
++0.2 > sctp: SACK[tsn=1]
 // Receive more data, observe delayed SACKi
-+1.0 < sctp: DATA[tsn=1 sid=0 ssn=1 ppid=0]
++1.0 < sctp: DATA[tsn=2 sid=0 ssn=2 ppid=0]
 +0.0 read(4, ..., 2000) = 1000
-+0.2 > sctp: SACK[tsn=1]
++0.2 > sctp: SACK[tsn=2]
 // Tear down the association
 +1.0 < sctp: SHUTDOWN[tsn=0]
 +0.0 > sctp: SHUTDOWN_ACK[]