static int read_packet(struct stream_pfring* st, int block){
assert(st);
do {
/* read next frame */
struct pfring_pkthdr hdr;
switch ( pfring_recv(st->pd, (u_char**)&st->frame[st->base.writePos], 0, &hdr, block) ){
case 0:
return 0;
case 1:
break;
case -1:
fprintf(stderr, "pfring_recv(..) failed.\n");
return 0;
}
char* dst = st->frame[st->base.writePos];
/* Setup pointers */
const struct ethhdr* eh = (const struct ethhdr*)dst;
const struct sendhead* sh = (const struct sendhead*)(dst + sizeof(struct ethhdr));
/* Check if it is a valid packet and if it was destinationed here */
int match;
if ( (match=match_ma_pkt(st, eh)) == -1 ){
continue;
}
#ifdef DEBUG
fprintf(stderr, "got measurement frame with %d capture packets [BU: %3.2f%%]\n", ntohl(sh->nopkts), 0.0f);
#endif
/* increase packet count */
st->base.stat.recv += ntohl(sh->nopkts);
/* if no sequencenr is set some additional checks are made.
* they will also run when the sequence number wraps, but that ok since the
* sequence number will match in that case anyway. */
if ( st->seqnum[match] == 0 ){
/* read stream version */
struct file_header_t FH;
FH.version.major=ntohs(sh->version.major);
FH.version.minor=ntohs(sh->version.minor);
/* ensure we can read this version */
if ( !is_valid_version(&FH) ){
perror("invalid stream version");
break;
}
/* this is set last, as we want to wait until a packet with valid version
* arrives before proceeding. */
st->seqnum[match] = ntohl(sh->sequencenr);
}
match_inc_seqnr(&st->base, &st->seqnum[match], sh);
st->base.writePos = (st->base.writePos+1) % st->num_frames;
/* This indicates a flush from the sender.. */
if( ntohs(sh->flush) == 1 ){
fprintf(stderr, "Sender terminated.\n");
st->base.flushed=1;
}
return 1;
} while (1);
return 0;
}
static int stream_ethernet_read_frame(struct stream_ethernet* st, char* dst, struct timeval* timeout){
assert(st);
assert(dst);
do {
fd_set fds;
FD_ZERO(&fds);
FD_SET(st->socket, &fds);
if ( select(st->socket+1, &fds, NULL, NULL, timeout) != 1 ){
break;
}
/* Read data into framebuffer. */
int bytes = recvfrom(st->socket, dst, st->fb.frame_size, 0, NULL, NULL);
if ( bytes < 0 ){ /* error occurred */
perror("Cannot receive Ethernet data.");
break;
} else if ( bytes == 0 ){ /* proper shutdown */
perror("Connection closed by client.");
break;
}
/* Setup pointers */
const struct ethhdr* eh = (const struct ethhdr*)dst;
const struct sendhead* sh = (const struct sendhead*)(dst + sizeof(struct ethhdr));
/* Check if it is a valid packet and if it was destinationed here */
int match;
if ( (match=match_ma_pkt(st, eh)) == -1 ){
continue;
}
#ifdef DEBUG
fprintf(stderr, "got measurement frame with %d capture packets [BU: %3.2f%%]\n", ntohl(sh->nopkts), 0.0f);
fprintf(stderr, " address: %s (%d)\n", hexdump_address(&st->address[match]), match);
#endif
/* validate frame */
if ( !valid_framesize(bytes, sh) ){
/* error message already shown */
continue;
}
/* increase packet count */
st->base.stat.recv += ntohl(sh->nopkts);
/* if no sequencenr is set some additional checks are made.
* they will also run when the sequence number wraps, but that ok since the
* sequence number will match in that case anyway. */
if ( st->seqnum[match] == 0 ){
/* read stream version */
struct file_header_t FH;
FH.version.major=ntohs(sh->version.major);
FH.version.minor=ntohs(sh->version.minor);
/* ensure we can read this version */
if ( !is_valid_version(&FH) ){
perror("invalid stream version");
break;
}
/* this is set last, as we want to wait until a packet with valid version
* arrives before proceeding. */
st->seqnum[match] = ntohl(sh->sequencenr);
}
match_inc_seqnr(&st->base, &st->seqnum[match], sh);
/* This indicates a flush from the sender.. */
if( ntohl(sh->flags) & SENDER_FLUSH ){
fprintf(stderr, "Sender terminated.\n");
st->base.flushed=1;
}
return 1;
} while (1);
return 0;
}