/**
* Decode SDES items from a buffer
*
* @param mb Buffer to decode from
* @param sdes RTCP SDES to decode into
*
* @return 0 if success, otherwise errorcode
*/
int rtcp_sdes_decode(struct mbuf *mb, struct rtcp_sdes *sdes)
{
size_t start;
if (!sdes)
return EINVAL;
if (mbuf_get_left(mb) < RTCP_SRC_SIZE)
return EBADMSG;
start = mb->pos;
sdes->src = ntohl(mbuf_read_u32(mb));
/* Decode all SDES items */
while (mbuf_get_left(mb) >= RTCP_SDES_MIN_SIZE) {
uint8_t type;
struct rtcp_sdes_item *item;
type = mbuf_read_u8(mb);
if (type == RTCP_SDES_END)
break;
if (mbuf_get_left(mb) < 1)
return EBADMSG;
if (!sdes->itemv) {
sdes->itemv = mem_alloc(sizeof(*sdes->itemv), NULL);
if (!sdes->itemv)
return ENOMEM;
}
else {
const size_t sz = (sdes->n + 1) * sizeof(*sdes->itemv);
struct rtcp_sdes_item *itemv;
itemv = mem_realloc(sdes->itemv, sz);
if (!itemv)
return ENOMEM;
sdes->itemv = itemv;
}
item = &sdes->itemv[sdes->n];
item->type = (enum rtcp_sdes_type)type;
item->length = mbuf_read_u8(mb);
if (mbuf_get_left(mb) < item->length)
return EBADMSG;
item->data = mem_alloc(item->length, NULL);
if (!item->data)
return ENOMEM;
(void)mbuf_read_mem(mb, (uint8_t *)item->data, item->length);
sdes->n++;
}
/* slurp padding */
while ((mb->pos - start) & 0x3 && mbuf_get_left(mb))
++mb->pos;
return 0;
}
/**
* Duplicate a null-terminated string from a memory buffer
*
* @param mb Memory buffer
* @param strp Pointer to destination string; allocated and set
* @param len Length of string
*
* @return 0 if success, otherwise errorcode
*/
int mbuf_strdup(struct mbuf *mb, char **strp, size_t len)
{
char *str;
int err;
if (!mb || !strp)
return EINVAL;
str = mem_alloc(len + 1, NULL);
if (!str)
return ENOMEM;
err = mbuf_read_mem(mb, (uint8_t *)str, len);
if (err)
goto out;
str[len] = '\0';
out:
if (err)
mem_deref(str);
else
*strp = str;
return err;
}
/**
* Decode an RTP header from a buffer
*
* @param hdr RTP Header to decode into
* @param mb Buffer to decode from
*
* @return 0 if success, otherwise errorcode
*/
int rtp_hdr_decode(struct rtp_header *hdr, struct mbuf *mb)
{
uint8_t buf[2];
int err, i;
size_t header_len;
if (!hdr || !mb)
return EINVAL;
if (mbuf_get_left(mb) < RTP_HEADER_SIZE)
return EBADMSG;
err = mbuf_read_mem(mb, buf, sizeof(buf));
if (err)
return err;
hdr->ver = (buf[0] >> 6) & 0x03;
hdr->pad = (buf[0] >> 5) & 0x01;
hdr->ext = (buf[0] >> 4) & 0x01;
hdr->cc = (buf[0] >> 0) & 0x0f;
hdr->m = (buf[1] >> 7) & 0x01;
hdr->pt = (buf[1] >> 0) & 0x7f;
hdr->seq = ntohs(mbuf_read_u16(mb));
hdr->ts = ntohl(mbuf_read_u32(mb));
hdr->ssrc = ntohl(mbuf_read_u32(mb));
header_len = hdr->cc*sizeof(uint32_t);
if (mbuf_get_left(mb) < header_len)
return EBADMSG;
for (i=0; i<hdr->cc; i++) {
hdr->csrc[i] = ntohl(mbuf_read_u32(mb));
}
if (hdr->ext) {
if (mbuf_get_left(mb) < 4)
return EBADMSG;
hdr->x.type = ntohs(mbuf_read_u16(mb));
hdr->x.len = ntohs(mbuf_read_u16(mb));
if (mbuf_get_left(mb) < hdr->x.len*sizeof(uint32_t))
return EBADMSG;
mb->pos += hdr->x.len*sizeof(uint32_t);
}
return 0;
}
/**
* NOTE: DSP cannot be destroyed inside handler
*/
static bool write_handler(uint8_t *buf, size_t sz, void *arg)
{
struct play *play = arg;
lock_write_get(play->lock);
if (play->eof)
goto silence;
if (mbuf_get_left(play->mb) < sz) {
play->eof = true;
}
else {
(void)mbuf_read_mem(play->mb, buf, sz);
}
silence:
if (play->eof)
memset(buf, 0, sz);
lock_rel(play->lock);
return true;
}
int stun_hdr_decode(struct mbuf *mb, struct stun_hdr *hdr)
{
if (!mb || !hdr)
return EINVAL;
if (mbuf_get_left(mb) < STUN_HEADER_SIZE)
return EBADMSG;
hdr->type = ntohs(mbuf_read_u16(mb));
if (hdr->type & 0xc000)
return EBADMSG;
hdr->len = ntohs(mbuf_read_u16(mb));
if (hdr->len & 0x3)
return EBADMSG;
hdr->cookie = ntohl(mbuf_read_u32(mb));
(void)mbuf_read_mem(mb, hdr->tid, sizeof(hdr->tid));
if (mbuf_get_left(mb) < hdr->len)
return EBADMSG;
return 0;
}
/**
* Read a 64-bit value from a memory buffer
*
* @param mb Memory buffer
*
* @return 64-bit value
*/
uint64_t mbuf_read_u64(struct mbuf *mb)
{
uint64_t v;
return (0 == mbuf_read_mem(mb, (uint8_t *)&v, sizeof(v))) ? v : 0;
}
/**
* Read an 8-bit value from a memory buffer
*
* @param mb Memory buffer
*
* @return 8-bit value
*/
uint8_t mbuf_read_u8(struct mbuf *mb)
{
uint8_t v;
return (0 == mbuf_read_mem(mb, &v, sizeof(v))) ? v : 0;
}
int stun_attr_decode(struct stun_attr **attrp, struct mbuf *mb,
const uint8_t *tid, struct stun_unknown_attr *ua)
{
struct stun_attr *attr;
size_t start, len;
uint32_t i, n;
int err = 0;
if (!mb || !attrp)
return EINVAL;
if (mbuf_get_left(mb) < 4)
return EBADMSG;
attr = mem_zalloc(sizeof(*attr), destructor);
if (!attr)
return ENOMEM;
attr->type = htons(mbuf_read_u16(mb));
len = htons(mbuf_read_u16(mb));
if (mbuf_get_left(mb) < len)
goto badmsg;
start = mb->pos;
switch (attr->type) {
case STUN_ATTR_MAPPED_ADDR:
case STUN_ATTR_ALT_SERVER:
case STUN_ATTR_RESP_ORIGIN:
case STUN_ATTR_OTHER_ADDR:
tid = NULL;
/*@fallthrough@*/
case STUN_ATTR_XOR_PEER_ADDR:
case STUN_ATTR_XOR_RELAY_ADDR:
case STUN_ATTR_XOR_MAPPED_ADDR:
err = stun_addr_decode(mb, &attr->v.sa, tid);
break;
case STUN_ATTR_CHANGE_REQ:
if (len != 4)
goto badmsg;
n = ntohl(mbuf_read_u32(mb));
attr->v.change_req.ip = (n >> 2) & 0x1;
attr->v.change_req.port = (n >> 1) & 0x1;
break;
case STUN_ATTR_USERNAME:
case STUN_ATTR_REALM:
case STUN_ATTR_NONCE:
case STUN_ATTR_SOFTWARE:
err = str_decode(mb, &attr->v.str, len);
break;
case STUN_ATTR_MSG_INTEGRITY:
if (len != 20)
goto badmsg;
err = mbuf_read_mem(mb, attr->v.msg_integrity, 20);
break;
case STUN_ATTR_ERR_CODE:
if (len < 4)
goto badmsg;
mb->pos += 2;
attr->v.err_code.code = (mbuf_read_u8(mb) & 0x7) * 100;
attr->v.err_code.code += mbuf_read_u8(mb);
err = str_decode(mb, &attr->v.err_code.reason, len - 4);
break;
case STUN_ATTR_UNKNOWN_ATTR:
for (i=0; i<len/2; i++) {
uint16_t type = ntohs(mbuf_read_u16(mb));
if (i >= ARRAY_SIZE(attr->v.unknown_attr.typev))
continue;
attr->v.unknown_attr.typev[i] = type;
attr->v.unknown_attr.typec++;
}
break;
case STUN_ATTR_CHANNEL_NUMBER:
case STUN_ATTR_RESP_PORT:
if (len < 2)
goto badmsg;
attr->v.uint16 = ntohs(mbuf_read_u16(mb));
break;
case STUN_ATTR_LIFETIME:
case STUN_ATTR_PRIORITY:
case STUN_ATTR_FINGERPRINT:
if (len != 4)
goto badmsg;
attr->v.uint32 = ntohl(mbuf_read_u32(mb));
break;
case STUN_ATTR_DATA:
case STUN_ATTR_PADDING:
attr->v.mb.buf = mem_ref(mb->buf);
attr->v.mb.size = mb->size;
attr->v.mb.pos = mb->pos;
attr->v.mb.end = mb->pos + len;
mb->pos += len;
break;
case STUN_ATTR_REQ_ADDR_FAMILY:
case STUN_ATTR_REQ_TRANSPORT:
if (len < 1)
goto badmsg;
attr->v.uint8 = mbuf_read_u8(mb);
break;
case STUN_ATTR_EVEN_PORT:
if (len < 1)
goto badmsg;
attr->v.even_port.r = (mbuf_read_u8(mb) >> 7) & 0x1;
break;
case STUN_ATTR_DONT_FRAGMENT:
case STUN_ATTR_USE_CAND:
if (len > 0)
goto badmsg;
/* no value */
break;
case STUN_ATTR_RSV_TOKEN:
case STUN_ATTR_CONTROLLING:
case STUN_ATTR_CONTROLLED:
if (len != 8)
goto badmsg;
attr->v.uint64 = sys_ntohll(mbuf_read_u64(mb));
break;
default:
mb->pos += len;
if (attr->type >= 0x8000)
break;
if (ua && ua->typec < ARRAY_SIZE(ua->typev))
ua->typev[ua->typec++] = attr->type;
break;
}
if (err)
goto error;
/* padding */
while (((mb->pos - start) & 0x03) && mbuf_get_left(mb))
++mb->pos;
*attrp = attr;
return 0;
badmsg:
err = EBADMSG;
error:
mem_deref(attr);
return err;
}
int srtp_decrypt(struct srtp *srtp, struct mbuf *mb)
{
struct srtp_stream *strm;
struct rtp_header hdr;
struct comp *comp;
uint64_t ix;
size_t start;
int diff;
int err;
if (!srtp || !mb)
return EINVAL;
comp = &srtp->rtp;
start = mb->pos;
err = rtp_hdr_decode(&hdr, mb);
if (err)
return err;
err = stream_get_seq(&strm, srtp, hdr.ssrc, hdr.seq);
if (err)
return err;
diff = seq_diff(strm->s_l, hdr.seq);
if (diff > 32768)
return ETIMEDOUT;
/* Roll-Over Counter (ROC) */
if (diff <= -32768) {
strm->roc++;
strm->s_l = 0;
}
ix = srtp_get_index(strm->roc, strm->s_l, hdr.seq);
if (comp->hmac) {
uint8_t tag_calc[SHA_DIGEST_LENGTH];
uint8_t tag_pkt[SHA_DIGEST_LENGTH];
size_t pld_start, tag_start;
if (mbuf_get_left(mb) < comp->tag_len)
return EBADMSG;
pld_start = mb->pos;
tag_start = mb->end - comp->tag_len;
mb->pos = tag_start;
err = mbuf_read_mem(mb, tag_pkt, comp->tag_len);
if (err)
return err;
mb->pos = mb->end = tag_start;
err = mbuf_write_u32(mb, htonl(strm->roc));
if (err)
return err;
mb->pos = start;
err = hmac_digest(comp->hmac, tag_calc, sizeof(tag_calc),
mbuf_buf(mb), mbuf_get_left(mb));
if (err)
return err;
mb->pos = pld_start;
mb->end = tag_start;
if (0 != memcmp(tag_calc, tag_pkt, comp->tag_len))
return EAUTH;
/*
* 3.3.2. Replay Protection
*
* Secure replay protection is only possible when
* integrity protection is present.
*/
if (!srtp_replay_check(&strm->replay_rtp, ix))
return EALREADY;
}
if (comp->aes) {
union vect128 iv;
uint8_t *p = mbuf_buf(mb);
srtp_iv_calc(&iv, &comp->k_s, strm->ssrc, ix);
aes_set_iv(comp->aes, iv.u8);
err = aes_decr(comp->aes, p, p, mbuf_get_left(mb));
if (err)
return err;
}
if (hdr.seq > strm->s_l)
strm->s_l = hdr.seq;
mb->pos = start;
return 0;
}
static void recv_handler(struct mbuf *mb, void *arg)
{
struct rst *rst = arg;
size_t n;
if (!rst->head_recv) {
struct pl hdr, name, metaint, eoh;
if (rst->mb) {
size_t pos;
int err;
pos = rst->mb->pos;
rst->mb->pos = rst->mb->end;
err = mbuf_write_mem(rst->mb, mbuf_buf(mb),
mbuf_get_left(mb));
if (err) {
re_printf("rst: buffer write error: %m\n",
err);
rst->tc = mem_deref(rst->tc);
tmr_start(&rst->tmr, RETRY_WAIT,
reconnect, rst);
return;
}
rst->mb->pos = pos;
}
else {
rst->mb = mem_ref(mb);
}
if (re_regex((const char *)mbuf_buf(rst->mb),
mbuf_get_left(rst->mb),
"[^\r\n]1\r\n\r\n", &eoh))
return;
rst->head_recv = true;
hdr.p = (const char *)mbuf_buf(rst->mb);
hdr.l = eoh.p + 5 - hdr.p;
if (!re_regex(hdr.p, hdr.l, "icy-name:[ \t]*[^\r\n]+\r\n",
NULL, &name))
(void)pl_strdup(&rst->name, &name);
if (!re_regex(hdr.p, hdr.l, "icy-metaint:[ \t]*[0-9]+\r\n",
NULL, &metaint))
rst->metaint = pl_u32(&metaint);
if (rst->metaint == 0) {
re_printf("rst: icy meta interval not available\n");
rst->tc = mem_deref(rst->tc);
tmr_start(&rst->tmr, RETRY_WAIT, reconnect, rst);
return;
}
rst_video_update(rst->vidsrc_st, rst->name, NULL);
rst->mb->pos += hdr.l;
re_printf("rst: name='%s' metaint=%zu\n",
rst->name, rst->metaint);
if (rst->mb->pos >= rst->mb->end)
return;
mb = rst->mb;
}
while (mb->pos < mb->end) {
if (rst->metasz > 0) {
n = min(mbuf_get_left(mb), rst->metasz - rst->bytec);
if (rst->meta)
mbuf_read_mem(mb,
(uint8_t *)&rst->meta[rst->bytec],
n);
else
mb->pos += n;
rst->bytec += n;
#if 0
re_printf("rst: metadata %zu bytes\n", n);
#endif
if (rst->bytec >= rst->metasz) {
#if 0
re_printf("rst: metadata: [%s]\n", rst->meta);
#endif
rst->metasz = 0;
rst->bytec = 0;
rst_video_update(rst->vidsrc_st, rst->name,
rst->meta);
}
}
else if (rst->bytec < rst->metaint) {
n = min(mbuf_get_left(mb), rst->metaint - rst->bytec);
rst_audio_feed(rst->ausrc_st, mbuf_buf(mb), n);
rst->bytec += n;
mb->pos += n;
#if 0
re_printf("rst: mp3data %zu bytes\n", n);
#endif
}
else {
rst->metasz = mbuf_read_u8(mb) * 16;
rst->bytec = 0;
rst->meta = mem_deref(rst->meta);
rst->meta = mem_zalloc(rst->metasz + 1, NULL);
#if 0
re_printf("rst: metalength %zu bytes\n", rst->metasz);
#endif
}
}
}
/**
* Decode one RTCP message from a buffer
*
* @param msgp Pointer to allocated RTCP Message
* @param mb Buffer to decode from
*
* @return 0 for success, otherwise errorcode
*/
int rtcp_decode(struct rtcp_msg **msgp, struct mbuf *mb)
{
struct rtcp_msg *msg = NULL;
size_t start, i, sz, count, rem;
int err;
if (!msgp)
return EINVAL;
if (mbuf_get_left(mb) < RTCP_HDR_SIZE)
return EBADMSG;
msg = mem_zalloc(sizeof(*msg), rtcp_destructor);
if (!msg)
return ENOMEM;
start = mb->pos;
/* decode and check header */
err = rtcp_hdr_decode(mb, &msg->hdr);
if (err)
goto out;
if (msg->hdr.version != RTCP_VERSION)
goto badmsg;
/* check length and remaining */
rem = msg->hdr.length * sizeof(uint32_t);
if (mbuf_get_left(mb) < rem)
goto badmsg;
count = msg->hdr.count;
switch (msg->hdr.pt) {
case RTCP_SR:
if (mbuf_get_left(mb) < (RTCP_SRC_SIZE + RTCP_SR_SIZE))
goto badmsg;
msg->r.sr.ssrc = ntohl(mbuf_read_u32(mb));
msg->r.sr.ntp_sec = ntohl(mbuf_read_u32(mb));
msg->r.sr.ntp_frac = ntohl(mbuf_read_u32(mb));
msg->r.sr.rtp_ts = ntohl(mbuf_read_u32(mb));
msg->r.sr.psent = ntohl(mbuf_read_u32(mb));
msg->r.sr.osent = ntohl(mbuf_read_u32(mb));
err = rtcp_rr_alloc(&msg->r.sr.rrv, count);
if (err)
goto out;
for (i=0; i<count && !err; i++)
err = rtcp_rr_decode(mb, &msg->r.sr.rrv[i]);
break;
case RTCP_RR:
if (mbuf_get_left(mb) < RTCP_SRC_SIZE)
goto badmsg;
msg->r.rr.ssrc = ntohl(mbuf_read_u32(mb));
err = rtcp_rr_alloc(&msg->r.rr.rrv, count);
if (err)
goto out;
for (i=0; i<count && !err; i++)
err = rtcp_rr_decode(mb, &msg->r.rr.rrv[i]);
break;
case RTCP_SDES:
if (count == 0)
break;
sz = count * sizeof(*msg->r.sdesv);
msg->r.sdesv = mem_zalloc(sz, NULL);
if (!msg->r.sdesv) {
err = ENOMEM;
goto out;
}
for (i=0; i<msg->hdr.count && !err; i++)
err = rtcp_sdes_decode(mb, &msg->r.sdesv[i]);
break;
case RTCP_BYE:
sz = count * sizeof(*msg->r.bye.srcv);
msg->r.bye.srcv = mem_alloc(sz, NULL);
if (!msg->r.bye.srcv) {
err = ENOMEM;
goto out;
}
if (mbuf_get_left(mb) < sz)
goto badmsg;
for (i=0; i<count; i++)
msg->r.bye.srcv[i] = ntohl(mbuf_read_u32(mb));
/* decode reason (optional) */
if (rem > count*sizeof(uint32_t)) {
const size_t len = mbuf_read_u8(mb);
if (mbuf_get_left(mb) < len)
goto badmsg;
err = mbuf_strdup(mb, &msg->r.bye.reason, len);
}
break;
case RTCP_APP:
if (mbuf_get_left(mb) < RTCP_APP_SIZE)
goto badmsg;
msg->r.app.src = ntohl(mbuf_read_u32(mb));
(void)mbuf_read_mem(mb, (uint8_t *)msg->r.app.name,
sizeof(msg->r.app.name));
if (rem > RTCP_APP_SIZE) {
msg->r.app.data_len = rem - RTCP_APP_SIZE;
msg->r.app.data = mem_alloc(msg->r.app.data_len, NULL);
if (!msg->r.app.data) {
err = ENOMEM;
goto out;
}
if (mbuf_get_left(mb) < msg->r.app.data_len)
goto badmsg;
(void)mbuf_read_mem(mb, msg->r.app.data,
msg->r.app.data_len);
}
break;
case RTCP_FIR:
if (mbuf_get_left(mb) < RTCP_FIR_SIZE)
goto badmsg;
msg->r.fir.ssrc = ntohl(mbuf_read_u32(mb));
break;
case RTCP_NACK:
if (mbuf_get_left(mb) < RTCP_NACK_SIZE)
goto badmsg;
msg->r.nack.ssrc = ntohl(mbuf_read_u32(mb));
msg->r.nack.fsn = ntohs(mbuf_read_u16(mb));
msg->r.nack.blp = ntohs(mbuf_read_u16(mb));
break;
case RTCP_RTPFB:
if (mbuf_get_left(mb) < RTCP_FB_SIZE)
goto badmsg;
msg->r.fb.ssrc_packet = ntohl(mbuf_read_u32(mb));
msg->r.fb.ssrc_media = ntohl(mbuf_read_u32(mb));
msg->r.fb.n = msg->hdr.length - 2;
err = rtcp_rtpfb_decode(mb, msg);
break;
case RTCP_PSFB:
if (mbuf_get_left(mb) < RTCP_FB_SIZE)
goto badmsg;
msg->r.fb.ssrc_packet = ntohl(mbuf_read_u32(mb));
msg->r.fb.ssrc_media = ntohl(mbuf_read_u32(mb));
msg->r.fb.n = msg->hdr.length - 2;
err = rtcp_psfb_decode(mb, msg);
break;
default:
/* unknown message type */
mbuf_advance(mb, rem);
break;
}
if (err)
goto out;
/* slurp padding */
while ((mb->pos - start) & 0x3 && mbuf_get_left(mb))
++mb->pos;
out:
if (err)
mem_deref(msg);
else
*msgp = msg;
return err;
badmsg:
mem_deref(msg);
return EBADMSG;
}
