153 lines
3.5 KiB
C
153 lines
3.5 KiB
C
#include <stdlib.h>
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#include "capwap.h"
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#include "cw_log.h"
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#include "conn.h"
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static int cwrmsg_init_ctrlhdr(struct cwrmsg * cwrmsg, uint8_t * msg, int len)
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{
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if (len<8)
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return 0;
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uint32_t val;
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val = ntohl(*((uint32_t*)(msg+0)));
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cwrmsg->type = ntohl(*((uint32_t*)(msg)))-CWIANA_ENTERPRISE_NUMBER*256;
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val = ntohl(*((uint32_t*)(msg+4)));
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cwrmsg->seqnum = CW_GET_DWORD_BITS(val,0,8);
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cwrmsg->msgelems_len=CW_GET_DWORD_BITS(val,8,16)-3;
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// ch->flags=CW_GET_DWORD_BITS(val,24,8);
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cwrmsg->msgelems=msg+8;
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if (8+cwrmsg->msgelems_len != len){
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return 0;
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}
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return 1;
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}
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static int process_message(struct conn * conn,struct cwrmsg *cwrmsg,int (*cb)(void*,struct cwrmsg *),void *cbarg)
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{
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if (!(cwrmsg->type & 0x1)) {
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/* It's a response message, no further examination required. */
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// conn->process_message(conn->pmsgarg,cwrmsg);
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cb(cbarg,cwrmsg);
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return 0;
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}
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/* It's a request message, check if seqnum is right and if
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* we have already sent a response message*/
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int s1=conn->last_seqnum_received;
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int s2=cwrmsg->seqnum;
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int sd=s2-s1;
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if ((sd>0 && sd<128) || (sd<0 && sd<-128) || s1<0){
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/* seqnum is ok, normal message processing */
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// conn->last_seqnum_received=cwrmsg->seqnum;
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cb(cbarg,cwrmsg);
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return 0;
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}
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if (sd != 0)
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{
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cw_log_debug0("Discarding message, old seqnum, seqnum = %d, last seqnum=%d",s2,s1);
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return 1;
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}
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/* the received request message was retransmitte by our peer,
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* let's retransmit our response message if we have one*/
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cw_log_debug0("Retransmitted request message detected, seqnum=%d",s2);
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if (!conn->last_response){
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cw_log_debug0("No cached response for retransmission, request seqnum=%d",s2);
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return 0;
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}
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cw_log_debug0("Retransmitting response message, seqnum=%d",s2);
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// cwmsg_send(conn->last_response,conn->last_response_seqnum,conn->last_response_rid,conn);
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conn_send_cwmsg(conn,conn->last_response);
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return 1;
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}
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void conn_process_packet(struct conn * conn, uint8_t *packet, int len,int (*cb)(void*,struct cwrmsg*),void *cbarg)
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{
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cw_log_debug2("Process conn Packet received, len=%d",len);
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if (len<8){
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/* packet too short */
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cw_log_debug0("Discarding packet, packet too short, len=%d",len);
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return;
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}
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uint32_t val = ntohl(*((uint32_t*)packet));
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int preamble = val >> 24;
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if ( (preamble & 0xf0) != CW_VERSION){
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/* wrong version */
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cw_log_debug0("Discarding packet, wrong version, version=%d",preamble&0xf0);
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return;
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}
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if (preamble & 0xf ) {
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/* decode dtls */
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return;
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}
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int hlen = 4*((val >> 19) & 0x1f);
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int payloadlen = len - hlen;
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if (payloadlen<0){
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cw_log_debug0("Discarding packet, hlen greater than len, hlen=%d",hlen);
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/* EINVAL */
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return;
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}
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struct cwrmsg cwrmsg;
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cwrmsg.wbid=(val>>9) & 0x1f;
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cwrmsg.rid=(val>>14) & 0x1f;
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#ifdef WITH_RMAC_SUPPORT
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if (val & CWTH_FLAGS_M){
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if (*(packet+8)+8>hlen){
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cw_log_debug0("Discarding packet, wrong rmac size, size=%d",*(packet+8));
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/* wrong rmac size */
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return;
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}
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cwrmsg.rmac = packet+8;
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}
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else
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cwrmsg.rmac=NULL;
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#endif
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if (val & CWTH_FLAGS_F){ /* fragmented */
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uint8_t * f;
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// printf("fragman add\n");
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f = fragman_add(conn->fragman, packet,hlen,payloadlen);
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if (f==NULL)
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return;
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// printf("complete\n");
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// printf ("msglen = %i\n",*((uint32_t*)f));
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cwrmsg_init_ctrlhdr(&cwrmsg,f+4,*(uint32_t*)f);
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process_message(conn,&cwrmsg,cb,cbarg); //packet,f+4,*(int32_t*)f);
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free (f);
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return;
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}
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cwrmsg_init_ctrlhdr(&cwrmsg,packet+hlen,len-hlen); //f+4,*(uint32_t*)f);
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process_message(conn,&cwrmsg,cb,cbarg); //packet,f+4,*(int32_t*)f);
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return;
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}
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