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-rw-r--r--contrib/librdns/resolver.c186
1 files changed, 161 insertions, 25 deletions
diff --git a/contrib/librdns/resolver.c b/contrib/librdns/resolver.c
index 8598cfdf5..c5cebc572 100644
--- a/contrib/librdns/resolver.c
+++ b/contrib/librdns/resolver.c
@@ -151,25 +151,6 @@ rdns_send_request (struct rdns_request *req, int fd, bool new_req)
}
-static struct rdns_reply *
-rdns_make_reply (struct rdns_request *req, enum dns_rcode rcode)
-{
- struct rdns_reply *rep;
-
- rep = malloc (sizeof (struct rdns_reply));
- if (rep != NULL) {
- rep->request = req;
- rep->resolver = req->resolver;
- rep->entries = NULL;
- rep->code = rcode;
- req->reply = rep;
- rep->flags = 0;
- rep->requested_name = req->requested_names[0].name;
- }
-
- return rep;
-}
-
static struct rdns_request *
rdns_find_dns_request (uint8_t *in, struct rdns_io_channel *ioc)
{
@@ -287,18 +268,173 @@ rdns_parse_reply (uint8_t *in, int r, struct rdns_request *req,
return true;
}
+static bool
+rdns_tcp_maybe_realloc_read_buf (struct rdns_io_channel *ioc)
+{
+ if (ioc->tcp->read_buf_allocated == 0 && ioc->tcp->next_read_size > 0) {
+ ioc->tcp->cur_read_buf = malloc(ioc->tcp->next_read_size);
+
+ if (ioc->tcp->cur_read_buf == NULL) {
+ return false;
+ }
+ ioc->tcp->read_buf_allocated = ioc->tcp->next_read_size;
+ }
+ else if (ioc->tcp->read_buf_allocated < ioc->tcp->next_read_size) {
+ /* Need to realloc */
+ unsigned next_shift = ioc->tcp->next_read_size;
+
+ if (next_shift < ioc->tcp->read_buf_allocated * 2) {
+ if (next_shift < UINT16_MAX && ioc->tcp->read_buf_allocated * 2 <= UINT16_MAX) {
+ next_shift = ioc->tcp->read_buf_allocated * 2;
+ }
+ }
+ void *next_buf = realloc(ioc->tcp->cur_read_buf, next_shift);
+
+ if (next_buf == NULL) {
+ free (ioc->tcp->cur_read_buf);
+ ioc->tcp->cur_read_buf = NULL;
+ return false;
+ }
+
+ ioc->tcp->cur_read_buf = next_buf;
+ }
+
+ return true;
+}
+
static void
rdns_process_tcp_read (int fd, struct rdns_io_channel *ioc)
{
+ ssize_t r;
+ struct rdns_resolver *resolver = ioc->resolver;
+
+ if (ioc->tcp->cur_read == 0) {
+ /* We have to read size first */
+ r = read(fd, &ioc->tcp->next_read_size, sizeof(ioc->tcp->next_read_size));
+
+ if (r == -1 || r == 0) {
+ goto err;
+ }
+
+ ioc->tcp->cur_read += r;
+
+ if (r == sizeof(ioc->tcp->next_read_size)) {
+ ioc->tcp->next_read_size = ntohl(ioc->tcp->next_read_size);
+
+ /* We have read the size, so we can try read one more time */
+ if (!rdns_tcp_maybe_realloc_read_buf(ioc)) {
+ rdns_err("failed to allocate %d bytes: %s",
+ (int)ioc->tcp->next_read_size, strerror(errno));
+ r = -1;
+ goto err;
+ }
+ }
+ else {
+ /* We have read one byte, need to retry... */
+ return;
+ }
+ }
+ else if (ioc->tcp->cur_read == 1) {
+ r = read(fd, ((unsigned char *)&ioc->tcp->next_read_size) + 1, 1);
+ if (r == -1 || r == 0) {
+ goto err;
+ }
+
+ ioc->tcp->cur_read += r;
+ ioc->tcp->next_read_size = ntohl(ioc->tcp->next_read_size);
+
+ /* We have read the size, so we can try read one more time */
+ if (!rdns_tcp_maybe_realloc_read_buf(ioc)) {
+ rdns_err("failed to allocate %d bytes: %s",
+ (int)ioc->tcp->next_read_size, strerror(errno));
+ r = -1;
+ goto err;
+ }
+ }
+
+ if (ioc->tcp->next_read_size < sizeof(struct dns_header)) {
+ /* Truncated reply, reset channel */
+ rdns_err("got truncated size: %d on TCP read", ioc->tcp->next_read_size);
+ r = -1;
+ errno = EINVAL;
+ goto err;
+ }
+
+ /* Try to read the full packet if we can */
+ int to_read = ioc->tcp->next_read_size - (ioc->tcp->cur_read - 2);
+
+ if (to_read <= 0) {
+ /* Internal error */
+ rdns_err("internal buffer error on reading!");
+ r = -1;
+ errno = EINVAL;
+ goto err;
+ }
+
+ r = read(fd, ioc->tcp->cur_read_buf + (ioc->tcp->cur_read - 2), to_read);
+ ioc->tcp->cur_read += r;
+
+ if ((ioc->tcp->cur_read - 2) == ioc->tcp->next_read_size) {
+ /* We have a full packet ready, process it */
+ struct rdns_request *req = rdns_find_dns_request (ioc->tcp->cur_read_buf, ioc);
+
+ if (req != NULL) {
+ struct rdns_reply *rep;
+
+ if (rdns_parse_reply (ioc->tcp->cur_read_buf,
+ ioc->tcp->next_read_size, req, &rep)) {
+ UPSTREAM_OK (req->io->srv);
+
+ if (req->resolver->ups && req->io->srv->ups_elt) {
+ req->resolver->ups->ok (req->io->srv->ups_elt,
+ req->resolver->ups->data);
+ }
+
+ rdns_request_unschedule (req);
+ req->state = RDNS_REQUEST_REPLIED;
+ req->func (rep, req->arg);
+ REF_RELEASE (req);
+ }
+ }
+ else {
+ rdns_warn("unwanted DNS id received over TCP");
+ }
+
+ ioc->tcp->next_read_size = 0;
+ ioc->tcp->cur_read = 0;
+
+ /* Retry read the next packet to avoid unnecessary polling */
+ rdns_process_tcp_read (fd, ioc);
+ }
+
+ return;
+
+err:
+ if (r == 0) {
+ /* Got EOF, just close the socket */
+ rdns_debug ("closing TCP channel due to EOF");
+ rdns_ioc_tcp_reset (ioc);
+ }
+ else if (errno == EINTR || errno == EAGAIN) {
+ /* We just retry later as there is no real error */
+ return;
+ }
+ else {
+ rdns_debug ("closing TCP channel due to IO error: %s", strerror(errno));
+ rdns_ioc_tcp_reset (ioc);
+ }
}
static void
rdns_process_tcp_connect (int fd, struct rdns_io_channel *ioc)
{
ioc->flags |= RDNS_CHANNEL_CONNECTED|RDNS_CHANNEL_ACTIVE;
- ioc->tcp->async_read = ioc->resolver->async->add_read(ioc->resolver->async->data,
- ioc->sock, ioc);
+
+ if (ioc->tcp->async_read == NULL) {
+ ioc->tcp->async_read = ioc->resolver->async->add_read(ioc->resolver->async->data,
+ ioc->sock, ioc);
+ }
}
static void
@@ -677,7 +813,7 @@ rdns_process_tcp_write (int fd, struct rdns_io_channel *ioc)
return;
}
}
- else if (oc->next_write_size < oc->cur_write) {
+ else if (ntohl(oc->next_write_size) < oc->cur_write) {
/* Packet has been fully written, remove it */
DL_DELETE(ioc->tcp->output_chain, oc);
/* Data in output buffer belongs to request */
@@ -937,20 +1073,20 @@ rdns_make_request_full (
if (!rdns_add_rr (req, cur_name, clen, type, &comp)) {
rdns_err ("cannot add rr");
REF_RELEASE (req);
- rnds_compression_free (comp);
+ rdns_compression_free(comp);
return NULL;
}
} else {
if (!rdns_add_rr (req, cur_name, clen, type, NULL)) {
rdns_err ("cannot add rr");
REF_RELEASE (req);
- rnds_compression_free (comp);
+ rdns_compression_free(comp);
return NULL;
}
}
}
- rnds_compression_free (comp);
+ rdns_compression_free(comp);
/* Add EDNS RR */
rdns_add_edns0 (req);
generated by cgit v1.2.3 (git 2.39.1) at 2025-01-16 01:11:03 +0000