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rtpengine
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generate stun responses and clean up some code mess

git.mgm/mediaproxy-ng/2.2
Richard Fuchs 13 years ago
parent
cbd26eb124
commit
2ea1fe3a47
1 changed files with 195 additions and 62 deletions
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  1. +195
    -62
      daemon/stun.c

+ 195
- 62
daemon/stun.c View File

@ -12,22 +12,17 @@
#define STUN_CRC_XOR 0x5354554eUL
#define STUN_USERNAME 0x0006
#define STUN_MESSAGE_INTEGRITY 0x0008
#define STUN_ERROR_CODE 0x0009
#define STUN_XOR_MAPPED_ADDRESS 0x0020
#define STUN_FINGERPRINT 0x8028
#define STUN_BINDING_SUCCESS_RESPONSE 0x0101
#define STUN_BINDING_ERROR_RESPONSE 0x0111
struct stun {
u_int16_t msg_type;
u_int16_t msg_len;
u_int32_t cookie;
unsigned char transaction[12];
} __attribute__ ((packed));
struct tlv {
u_int16_t type;
u_int16_t len;
} __attribute__ ((packed));
struct stun_attrs {
str username;
@ -41,17 +36,40 @@ struct stun_attrs {
controlling:1;
};
struct stun_error {
struct stun stun;
struct tlv error_code;
struct header {
u_int16_t msg_type;
u_int16_t msg_len;
u_int32_t cookie;
u_int32_t transaction[3];
} __attribute__ ((packed));
struct tlv {
u_int16_t type;
u_int16_t len;
} __attribute__ ((packed));
struct error_code {
struct tlv tlv;
u_int32_t codes;
} __attribute__ ((packed));
struct stun_fingerprint {
struct fingerprint {
struct tlv tlv;
u_int32_t crc;
} __attribute__ ((packed));
struct msg_integrity {
struct tlv tlv;
char digest[20];
} __attribute__ ((packed));
struct xor_mapped_address {
struct tlv tlv;
u_int16_t family;
u_int16_t port;
u_int32_t address[4];
} __attribute__ ((packed));
static int stun_attributes(struct stun_attrs *out, str *s) {
@ -119,45 +137,126 @@ out:
return 0;
}
static inline void stun_error_len(int fd, struct sockaddr_in6 *sin, struct stun *req,
static void output_init(struct msghdr *mh, struct iovec *iov, struct sockaddr_in6 *sin,
struct header *hdr, unsigned short code, u_int32_t *transaction)
{
ZERO(*mh);
mh->msg_name = sin;
mh->msg_namelen = sizeof(*sin);
mh->msg_iov = iov;
mh->msg_iovlen = 1;
iov->iov_base = hdr;
iov->iov_len = sizeof(*hdr);
hdr->msg_type = htons(code);
hdr->msg_len = 0;
hdr->cookie = htonl(STUN_COOKIE);
memcpy(&hdr->transaction, transaction, sizeof(hdr->transaction));
}
static inline void __output_add(struct msghdr *mh, struct tlv *tlv, unsigned int len, u_int16_t code,
void *append, unsigned int append_len)
{
struct iovec *iov;
struct header *hdr;
iov = &mh->msg_iov[mh->msg_iovlen++];
iov->iov_base = tlv;
iov->iov_len = len;
tlv->type = htons(code);
tlv->len = htons(len - sizeof(*tlv) + append_len);
hdr = mh->msg_iov->iov_base;
hdr->msg_len += len + ((append_len + 3) & 0xfffc);
if (append_len) {
iov = &mh->msg_iov[mh->msg_iovlen++];
iov->iov_base = append; /* must have space for padding */
iov->iov_len = (append_len + 3) & 0xfffc;
}
}
#define output_add(mh, attr, code) \
__output_add(mh, &(attr)->tlv, sizeof(*(attr)), code, NULL, 0)
#define output_add_len(mh, attr, code, len) \
__output_add(mh, &(attr)->tlv, len + sizeof(struct tlv), code, NULL, 0)
#define output_add_data(mh, attr, code, data, len) \
__output_add(mh, &(attr)->tlv, sizeof(*(attr)), code, data, len)
static void output_finish(struct msghdr *mh) {
struct header *hdr;
hdr = mh->msg_iov->iov_base;
hdr->msg_len = htons(hdr->msg_len);
}
static void fingerprint(struct msghdr *mh, struct fingerprint *fp) {
int i;
struct iovec *iov;
struct header *hdr;
output_add(mh, fp, STUN_FINGERPRINT);
iov = mh->msg_iov;
hdr = iov->iov_base;
hdr->msg_len = htons(hdr->msg_len);
fp->crc = crc32(0, NULL, 0);
for (i = 0; i < mh->msg_iovlen - 1; i++)
fp->crc = crc32(fp->crc, iov[i].iov_base, iov[i].iov_len);
fp->crc = htons(fp->crc ^ STUN_CRC_XOR);
hdr->msg_len = ntohs(hdr->msg_len);
}
static void __integrity(struct iovec *iov, int iov_cnt, str *pwd, char *digest) {
int i;
HMAC_CTX ctx;
HMAC_CTX_init(&ctx);
/* do we need to SASLprep here? */
HMAC_Init(&ctx, pwd->s, pwd->len, EVP_sha1());
for (i = 0; i < iov_cnt; i++)
HMAC_Update(&ctx, iov[i].iov_base, iov[i].iov_len);
HMAC_Final(&ctx, (void *) digest, NULL);
HMAC_CTX_cleanup(&ctx);
}
static void integrity(struct msghdr *mh, struct msg_integrity *mi, str *pwd) {
struct iovec *iov;
struct header *hdr;
output_add(mh, mi, STUN_MESSAGE_INTEGRITY);
iov = mh->msg_iov;
hdr = iov->iov_base;
hdr->msg_len = htons(hdr->msg_len);
__integrity(mh->msg_iov, mh->msg_iovlen - 1, pwd, mi->digest);
hdr->msg_len = ntohs(hdr->msg_len);
}
static void stun_error_len(int fd, struct sockaddr_in6 *sin, struct header *req,
int code, char *reason, int len)
{
struct stun_error err;
struct stun_fingerprint fp;
struct header hdr;
struct error_code ec;
struct fingerprint fp;
struct msghdr mh;
struct iovec iov[3];
struct iovec iov[4]; /* hdr, ec, reason, fp */
output_init(&mh, iov, sin, &hdr, STUN_BINDING_ERROR_RESPONSE, req->transaction);
ec.codes = htonl(((code / 100) << 8) | (code % 100));
output_add_data(&mh, &ec, STUN_ERROR_CODE, reason, len);
err.stun.msg_type = htons(0x0111); /* binding error response */
err.stun.cookie = htonl(STUN_COOKIE);
memcpy(&err.stun.transaction, &req->transaction, sizeof(err.stun.transaction));
err.error_code.type = htons(0x0009); /* error-code */
err.error_code.len = htons(len + sizeof(err.codes));
err.codes = htonl(((code / 100) << 8) | (code % 100));
ZERO(mh);
ZERO(iov);
iov[0].iov_base = &err;
iov[0].iov_len = sizeof(err);
iov[1].iov_base = reason;
iov[1].iov_len = (len + 3) & 0xfffc;
iov[2].iov_base = &fp;
iov[2].iov_len = sizeof(fp);
err.stun.msg_len = htons(iov[1].iov_len + sizeof(err.codes) + sizeof(err.error_code)
+ iov[2].iov_len);
fp.crc = crc32(0, iov[0].iov_base, iov[0].iov_len);
fp.crc = crc32(fp.crc, iov[1].iov_base, iov[1].iov_len);
fp.crc = htonl(fp.crc ^ STUN_CRC_XOR);
fp.tlv.type = htons(STUN_FINGERPRINT);
fp.tlv.len = htons(4);
mh.msg_name = sin;
mh.msg_namelen = sizeof(*sin);
mh.msg_iov = iov;
mh.msg_iovlen = 3;
fingerprint(&mh, &fp);
output_finish(&mh);
sendmsg(fd, &mh, 0);
}
@ -180,11 +279,10 @@ static int check_fingerprint(str *msg, struct stun_attrs *attrs) {
}
static int check_auth(str *msg, struct stun_attrs *attrs, struct peer *peer) {
HMAC_CTX ctx;
u_int16_t lenX;
unsigned char digest[20];
int ret;
char digest[20];
str ufrag[2];
struct iovec iov[3];
if (!peer->ice_ufrag[0].s || !peer->ice_ufrag[0].len)
return -1;
@ -203,25 +301,58 @@ static int check_auth(str *msg, struct stun_attrs *attrs, struct peer *peer) {
if (str_cmp_str(&ufrag[0], &peer->ice_ufrag[0]))
return -1;
HMAC_CTX_init(&ctx);
HMAC_Init(&ctx, peer->ice_pwd.s, peer->ice_pwd.len, EVP_sha1());
HMAC_Update(&ctx, (void *) msg->s, OFFSET_OF(struct stun, msg_len));
lenX = htons((attrs->msg_integrity_attr - msg->s) - 20 + 24);
HMAC_Update(&ctx, (void *) &lenX, sizeof(lenX));
HMAC_Update(&ctx, (void *) msg->s + OFFSET_OF(struct stun, cookie),
ntohs(lenX) + - 24 + 20 - OFFSET_OF(struct stun, cookie));
HMAC_Final(&ctx, digest, NULL);
iov[0].iov_base = msg->s;
iov[0].iov_len = OFFSET_OF(struct header, msg_len);
iov[1].iov_base = &lenX;
iov[1].iov_len = sizeof(lenX);
iov[2].iov_base = msg->s + OFFSET_OF(struct header, cookie);
iov[2].iov_len = ntohs(lenX) + - 24 + 20 - OFFSET_OF(struct header, cookie);
ret = memcmp(digest, attrs->msg_integrity.s, 20) ? -1 : 0;
__integrity(iov, ARRAYSIZE(iov), &peer->ice_pwd, digest);
HMAC_CTX_cleanup(&ctx);
return memcmp(digest, attrs->msg_integrity.s, 20) ? -1 : 0;
}
static int stun_binding_success(int fd, struct header *req, struct stun_attrs *attrs,
struct sockaddr_in6 *sin, struct peer *peer)
{
struct header hdr;
struct xor_mapped_address xma;
struct msg_integrity mi;
struct fingerprint fp;
struct msghdr mh;
struct iovec iov[4]; /* hdr, xma, mi, fp */
output_init(&mh, iov, sin, &hdr, STUN_BINDING_SUCCESS_RESPONSE, req->transaction);
xma.port = sin->sin6_port ^ htons(STUN_COOKIE >> 16);
if (IN6_IS_ADDR_V4MAPPED(&sin->sin6_addr)) {
xma.family = htons(0x01);
xma.address[0] = sin->sin6_addr.s6_addr32[3] ^ htonl(STUN_COOKIE);
output_add_len(&mh, &xma, STUN_XOR_MAPPED_ADDRESS, 8);
}
else {
xma.family = htons(0x02);
xma.address[0] = sin->sin6_addr.s6_addr32[0] ^ htonl(STUN_COOKIE);
xma.address[1] = sin->sin6_addr.s6_addr32[1] ^ req->transaction[0];
xma.address[2] = sin->sin6_addr.s6_addr32[2] ^ req->transaction[1];
xma.address[3] = sin->sin6_addr.s6_addr32[3] ^ req->transaction[2];
output_add(&mh, &xma, STUN_XOR_MAPPED_ADDRESS);
}
return ret;
integrity(&mh, &mi, &peer->ice_pwd);
fingerprint(&mh, &fp);
output_finish(&mh);
sendmsg(fd, &mh, 0);
return 0;
}
/* XXX add error reporting */
int stun(str *b, struct streamrelay *sr, struct sockaddr_in6 *sin) {
struct stun *s = (void *) b->s;
struct header *s = (void *) b->s;
int msglen, method, class;
str attr_str;
struct stun_attrs attrs;
@ -253,6 +384,8 @@ int stun(str *b, struct streamrelay *sr, struct sockaddr_in6 *sin) {
if (check_auth(b, &attrs, sr->up))
goto unauth;
stun_binding_success(sr->fd.fd, s, &attrs, sin, sr->up);
return 0;
bad_req:


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