tor_multipath_voip/src/packet.c

237 lines
7.6 KiB
C

#include "packet.h"
int ap_exists(union abstract_packet* ap) {
return ap->fmt.headers.cmd != 0;
}
int buffer_has_ap(struct buffer_packet* bp) {
return ap_exists(buffer_first_ap (bp));
}
union abstract_packet* ap_next(union abstract_packet* ap) {
if (ap_exists (ap) && ap->fmt.headers.flags & FLAG_READ_NEXT)
return (union abstract_packet*)(&ap->raw + ap->fmt.headers.size);
return NULL;
}
union abstract_packet* buffer_first_ap(struct buffer_packet* bp) {
return (union abstract_packet*) &bp->ip;
}
union abstract_packet* buffer_last_ap(struct buffer_packet* bp) {
union abstract_packet* ap = buffer_first_ap (bp), *apn = NULL;
while ((apn = ap_next(ap)) != NULL) ap = apn;
return ap;
}
union abstract_packet* buffer_free_ap(struct buffer_packet* bp) {
union abstract_packet* ap = buffer_last_ap (bp);
ap = (union abstract_packet*)(&ap->raw + ap->fmt.headers.size);
return ap;
}
size_t buffer_count_ap(struct buffer_packet* bp) {
size_t s = 1;
union abstract_packet* ap = (union abstract_packet*) &bp->ip;
while ((ap = ap_next(ap)) != NULL) s++;
return s;
}
size_t buffer_full_size(struct buffer_packet* bp) {
return &(buffer_free_ap (bp))->raw - &bp->ip[0];
}
union abstract_packet* buffer_append_ap(struct buffer_packet* bp, union abstract_packet* ap) {
if (buffer_has_ap (bp))
buffer_last_ap(bp)->fmt.headers.flags |= FLAG_READ_NEXT;
union abstract_packet *new_ap = buffer_last_ap(bp);
memcpy(new_ap, ap, ap->fmt.headers.size);
bp->ap_count++;
new_ap->fmt.headers.flags &= ~FLAG_READ_NEXT;
return new_ap;
}
enum FD_STATE read_packet_from_tcp(struct evt_core_fdinfo* fdinfo, struct buffer_packet* bp) {
ssize_t nread = 0, ap_aread = 0, cur_ap_aread = 0;
union abstract_packet* ap = buffer_first_ap (bp);
size_t pkt_size_size = sizeof(ap->fmt.headers.size);
if (bp->mode != BP_READING) return FDS_ERR;
//fprintf(stderr, "Entering read_packet_from_tcp\n");
do {
//fprintf(stderr, "bp->ap_count=%d\n", bp->ap_count);
ap = buffer_first_ap (bp);
ap_aread = 0;
for (int i = 0; i < bp->ap_count; i++) {
ap_aread += ap->fmt.headers.size;
ap = ap_next (ap);
}
cur_ap_aread = bp->aread - ap_aread;
//fprintf(stderr, "[size] bp_aread=%d, prev_ap_aread=%ld, cur_ap_aread=%ld\n", bp->aread, ap_aread, cur_ap_aread);
while (cur_ap_aread < pkt_size_size) {
nread = read(fdinfo->fd, &(ap->raw) + cur_ap_aread, pkt_size_size - cur_ap_aread);
if (nread == 0) return FDS_AGAIN;
if (nread == -1 && errno == EAGAIN) return FDS_AGAIN;
if (nread == -1) return FDS_ERR;
bp->aread += nread;
cur_ap_aread += nread;
}
//fprintf(stderr, "[content] bp_aread=%d, prev_ap_aread=%ld, cur_ap_aread=%ld\n", bp->aread, ap_aread, cur_ap_aread);
while (cur_ap_aread < ap->fmt.headers.size) {
nread = read(fdinfo->fd, &(ap->raw) + cur_ap_aread, ap->fmt.headers.size - cur_ap_aread);
if (nread == 0) return FDS_AGAIN;
if (nread == -1 && errno == EAGAIN) return FDS_AGAIN;
if (nread == -1) return FDS_ERR;
bp->aread += nread;
cur_ap_aread += nread;
}
bp->ap_count++;
//fprintf(stderr, "bp->ap_count=%d, buffer_count_ap(bp)=%ld\n", bp->ap_count, buffer_count_ap (bp));
//dump_buffer_packet (bp);
} while (bp->ap_count != buffer_count_ap (bp));
bp->mode = BP_WRITING;
bp->awrite = 0;
return FDS_READY;
}
enum FD_STATE write_packet_to_tcp(struct evt_core_fdinfo* fdinfo, struct buffer_packet* bp) {
ssize_t nwrite;
union abstract_packet* ap = (union abstract_packet*) &bp->ip;
//dump_buffer_packet (bp);
if (bp->mode != BP_WRITING) return FDS_ERR;
while (bp->awrite < buffer_full_size(bp)) {
nwrite = send(fdinfo->fd, &(ap->raw) + bp->awrite, buffer_full_size(bp) - bp->awrite, 0);
if (nwrite == -1 && errno == EAGAIN) return FDS_AGAIN;
if (nwrite == -1) return FDS_ERR;
bp->awrite += nwrite;
}
bp->mode = BP_READING;
bp->aread = 0;
bp->ap_count = 0;
return FDS_READY;
}
enum FD_STATE write_packet_to_udp(struct evt_core_fdinfo* fdinfo, struct buffer_packet* bp, struct udp_target* udp_t) {
ssize_t nwrite;
union abstract_packet* ap = (union abstract_packet*) (&bp->ip + bp->awrite);
if (bp->mode != BP_WRITING) return FDS_ERR;
do {
if (ap->fmt.headers.cmd != CMD_UDP_ENCAPSULATED) continue;
size_t bytes_to_send;
size_t pkt_header_size = sizeof(ap->fmt.headers) + sizeof(ap->fmt.content.udp_encapsulated) - sizeof(ap->fmt.content.udp_encapsulated.payload);
struct sockaddr* addr = NULL;
socklen_t addrlen = 0;
if (udp_t->set) {
addr = (struct sockaddr*) &udp_t->addr;
addrlen = sizeof(struct sockaddr_in);
}
bytes_to_send = ap->fmt.headers.size - pkt_header_size;
nwrite = sendto(fdinfo->fd,
&(ap->fmt.content.udp_encapsulated.payload),
bytes_to_send,
0,
addr,
addrlen);
if (nwrite == -1 && errno == EAGAIN) return FDS_AGAIN;
if (nwrite != bytes_to_send) return FDS_ERR;
bp->awrite += nwrite;
} while((ap = ap_next(ap)) != NULL);
bp->mode = BP_READING;
bp->aread = 0;
bp->ap_count = 0;
return FDS_READY;
}
enum FD_STATE read_packet_from_udp (struct evt_core_fdinfo* fdinfo, struct buffer_packet* bp, struct udp_target* udp_t) {
ssize_t nread;
union abstract_packet* ap = (union abstract_packet*) &bp->ip;
if (bp->mode != BP_READING) {
fprintf(stderr, "Buffer packet is not in reading mode (mode: %d)\n", bp->mode);
return FDS_ERR;
}
size_t pkt_header_size = sizeof(ap->fmt.headers) + sizeof(ap->fmt.content.udp_encapsulated) - sizeof(ap->fmt.content.udp_encapsulated.payload);
size_t udp_packet_size = sizeof(bp->ip) - pkt_header_size;
socklen_t addrlen = sizeof(struct sockaddr_in);
nread = recvfrom(fdinfo->fd,
&(ap->fmt.content.udp_encapsulated.payload),
udp_packet_size,
MSG_TRUNC,
(struct sockaddr*)&udp_t->addr,
&addrlen);
if ((int)nread > (int)udp_packet_size) {
fprintf(stderr, "Packet has been truncated (%ld instead of %d)\n", nread, (int)udp_packet_size);
return FDS_ERR;
}
if (nread == -1 && errno == EAGAIN) return FDS_AGAIN;
if (nread == 0) return FDS_AGAIN;
if (nread == -1) {
fprintf(stderr, "A system error occurred\n");
return FDS_ERR;
}
udp_t->set = 1;
udp_t->addrlen = addrlen;
ap->fmt.headers.size = nread + pkt_header_size;
ap->fmt.headers.cmd = CMD_UDP_ENCAPSULATED;
ap->fmt.content.udp_encapsulated.port = url_get_port_int (fdinfo->url);
bp->mode = BP_WRITING;
bp->awrite = 0;
bp->ap_count = 1;
return FDS_READY;
}
void dump_buffer_packet(struct buffer_packet* bp) {
printf("<Buffer Packet>\n");
printf(" mode=%d, aread=%d, awrite=%d, ap_count=%d, usage=%ld/%ld\n", bp->mode, bp->aread, bp->awrite, bp->ap_count, buffer_full_size (bp), sizeof(bp->ip));
for (union abstract_packet* ap = buffer_first_ap (bp); ap != NULL; ap = ap_next (ap)) {
dump_abstract_packet(ap);
}
printf("</Buffer Packet>\n");
}
void dump_abstract_packet(union abstract_packet* ap) {
printf(" <Abstract Packet>\n");
printf(" size=%d, cmd=%d\n", ap->fmt.headers.size, ap->fmt.headers.cmd);
switch (ap->fmt.headers.cmd) {
case CMD_LINK_MONITORING_THUNDER:
printf(" <LinkMonitoringThunder></LinkMonitoringThunder>\n");
break;
case CMD_UDP_METADATA_THUNDER:
printf(" <UdpMetadataThunder>id=%d</UdpMetadataThunder>\n",
ap->fmt.content.udp_metadata_thunder.id);
break;
case CMD_UDP_ENCAPSULATED:
printf(" <Payload>port=%d</Payload>\n", ap->fmt.content.udp_encapsulated.port);
break;
default:
printf(" <Unknown/>\n");
break;
}
printf(" </Abstract Packet>\n");
}