}
}
-size_t prepare_packet(void *vdata, size_t size, const char *name, const char *protocol, const char *transport, uint16_t port, int nkeys, const char **keys, const char **values, bool response) {
- // Create the request/response packet right now
+size_t prepare_request(void *vdata, size_t size, const char *protocol, const char *transport) {
uint8_t *data = vdata;
buf_t buf = {data, size};
// Header
buf_add_uint16(&buf, 0); // TX ID
- buf_add_uint16(&buf, response ? ntohs(1 << 15) : 0); // flags
+ buf_add_uint16(&buf, 0); // flags
buf_add_uint16(&buf, 1); // 1 question
- buf_add_uint16(&buf, 1); // 1 answer RR
+ buf_add_uint16(&buf, 0); // 0 answer RR
buf_add_uint16(&buf, 0); // 0 authority RRs
- buf_add_uint16(&buf, 2); // 1 additional RR
+ buf_add_uint16(&buf, 0); // 0 additional RR
// Question section: _protocol._transport.local PTR IN
buf_add_ulabel(&buf, protocol);
buf_add_ulabel(&buf, transport);
- uint16_t local = buf.ptr - data;
buf_add_label(&buf, "local");
buf_add_uint8(&buf, 0);
buf_add_uint16(&buf, 0xc); // PTR
buf_add_uint16(&buf, 0x1); // IN
- // Answer section: _protocol._transport local PTR IN 3600 name._protocol._transport
- buf_add_uint16(&buf, 0xc00c); // _protocol._transport.local
- buf_add_uint16(&buf, 0xc); // PTR
+ // Done.
+ if(buf.len < 0) {
+ return 0;
+ } else {
+ return buf.ptr - data;
+ }
+}
+
+bool parse_request(const void *vdata, size_t size, const char *protocol, const char *transport) {
+ const uint8_t *data = vdata;
+ cbuf_t buf = {data, size};
+
+ // Header
+ buf_get_uint16(&buf); // TX ID
+ buf_check_uint16(&buf, 0); // flags
+ buf_check_uint16(&buf, 1); // 1 question
+ buf_get_uint16(&buf); // ? answer RR
+ buf_get_uint16(&buf); // ? authority RRs
+ buf_get_uint16(&buf); // ? additional RR
+
+ if(buf.len == -1) {
+ return false;
+ }
+
+ // Question section: _protocol._transport.local PTR IN
+ buf_check_ulabel(&buf, protocol);
+ buf_check_ulabel(&buf, transport);
+ buf_check_label(&buf, "local");
+ buf_check_uint8(&buf, 0);
+ buf_check_uint16(&buf, 0xc); // PTR
+ buf_check_uint16(&buf, 0x1); // IN
+
+ if(buf.len == -1) {
+ return false;
+ }
+
+ // Done.
+ return buf.len != -1;
+}
+
+size_t prepare_response(void *vdata, size_t size, const char *name, const char *protocol, const char *transport, uint16_t port, int nkeys, const char **keys, const char **values) {
+ uint8_t *data = vdata;
+ buf_t buf = {data, size};
+
+ // Header
+ buf_add_uint16(&buf, 0); // TX ID
+ buf_add_uint16(&buf, 0x8400); // flags
+ buf_add_uint16(&buf, 0); // 1 question
+ buf_add_uint16(&buf, 3); // 1 answer RR
+ buf_add_uint16(&buf, 0); // 0 authority RRs
+ buf_add_uint16(&buf, 0); // 1 additional RR
+
+ // Add the TXT record: _protocol._transport local TXT IN 3600 name._protocol._transport key=value...
+ uint16_t full_name = buf.ptr - data; // remember start of full name
+ buf_add_label(&buf, name);
+ uint16_t protocol_offset = buf.ptr - data; // remember start of _protocol
+ buf_add_ulabel(&buf, protocol);
+ buf_add_ulabel(&buf, transport);
+ uint16_t local_offset = buf.ptr - data; // remember start of local
+ buf_add_label(&buf, "local");
+ buf_add_uint8(&buf, 0);
+ buf_add_uint16(&buf, 0x10); // TXT
buf_add_uint16(&buf, 0x1); // IN
buf_add_uint32(&buf, 3600); // TTL
+
uint8_t *len_ptr = buf_len_start(&buf);
- uint16_t full_name = buf.ptr - data; // remember start of full name
- buf_add_label(&buf, name);
- buf_add_uint16(&buf, 0xc00c); // _protocol._transport.local
+
+ for(int i = 0; i < nkeys; i++) {
+ buf_add_kvp(&buf, keys[i], values[i]);
+ }
+
+ buf_len_end(&buf, len_ptr);
+
+ // Add the PTR record: _protocol._transport.local PTR IN 3600 name._protocol._transport.local
+ buf_add_uint16(&buf, 0xc000 | protocol_offset);
+ buf_add_uint16(&buf, 0xc); // PTR
+ buf_add_uint16(&buf, 0x8001); // IN (flush)
+ buf_add_uint32(&buf, 3600); // TTL
+ len_ptr = buf_len_start(&buf);
+ buf_add_uint16(&buf, 0xc000 | full_name);
buf_len_end(&buf, len_ptr);
// Add the SRV record: name._protocol._transport.local SRV IN 120 0 0 port name.local
buf_add_uint16(&buf, 0xc000 | full_name);
buf_add_uint16(&buf, 0x21); // SRV
- buf_add_uint16(&buf, 0x1); // IN
+ buf_add_uint16(&buf, 0x8001); // IN (flush)
buf_add_uint32(&buf, 120); // TTL
len_ptr = buf_len_start(&buf);
buf_add_uint16(&buf, 0); // priority
buf_add_uint16(&buf, 0); // weight
buf_add_uint16(&buf, port); // port
buf_add_label(&buf, name);
- buf_add_uint16(&buf, 0xc000 | local);
- buf_len_end(&buf, len_ptr);
-
- // Add the TXT records: name._protocol._transport.local TXT IN 3600 key=value...
- buf_add_uint16(&buf, 0xc000 | full_name);
- buf_add_uint16(&buf, 0x10); // TXT
- buf_add_uint16(&buf, 0x1); // IN
- buf_add_uint32(&buf, 3600); // TTL
- len_ptr = buf_len_start(&buf);
-
- for(int i = 0; i < nkeys; i++) {
- buf_add_kvp(&buf, keys[i], values[i]);
- }
-
+ buf_add_uint16(&buf, 0xc000 | local_offset);
buf_len_end(&buf, len_ptr);
// Done.
}
}
-bool parse_packet(const void *vdata, size_t size, char **name, const char *protocol, const char *transport, uint16_t *port, int nkeys, const char **keys, char **values, bool *response) {
+bool parse_response(const void *vdata, size_t size, char **name, const char *protocol, const char *transport, uint16_t *port, int nkeys, const char **keys, char **values) {
const uint8_t *data = vdata;
cbuf_t buf = {data, size};
// Header
buf_check_uint16(&buf, 0); // TX ID
- uint16_t flags = buf_get_uint16(&buf); // flags
- buf_check_uint16(&buf, 1); // 1 question
- buf_check_uint16(&buf, 1); // 1 answer RR
+ buf_check_uint16(&buf, 0x8400); // flags
+ buf_check_uint16(&buf, 0); // 0 question
+ buf_check_uint16(&buf, 3); // 1 answer RR
buf_check_uint16(&buf, 0); // 0 authority RRs
- buf_check_uint16(&buf, 2); // 1 checkitional RR
+ buf_check_uint16(&buf, 0); // 0 checkitional RR
- if(buf.len == -1 || flags & ~ntohs(1 << 15)) {
+ if(buf.len == -1) {
return false;
}
- *response = flags & ntohs(1 << 15);
-
- // Question section: _protocol._transport.local PTR IN
+ // Check the TXT record: _protocol._transport local TXT IN 3600 name._protocol._transport key=value...
+ uint16_t full_name = buf.ptr - data; // remember start of full name
+ *name = buf_get_label(&buf);
+ uint16_t protocol_offset = buf.ptr - data; // remember start of _protocol
buf_check_ulabel(&buf, protocol);
buf_check_ulabel(&buf, transport);
- uint16_t local = buf.ptr - data;
+ uint16_t local_offset = buf.ptr - data; // remember start of local
buf_check_label(&buf, "local");
buf_check_uint8(&buf, 0);
- buf_check_uint16(&buf, 0xc); // PTR
+ buf_check_uint16(&buf, 0x10); // TXT
buf_check_uint16(&buf, 0x1); // IN
+ buf_check_uint32(&buf, 3600); // TTL
+ const uint8_t *len_ptr = buf_check_len_start(&buf);
+
+ for(int i = 0; i < nkeys; i++) {
+ buf_get_kvp(&buf, keys[i], &values[i]);
+ }
+
+ buf_check_len_end(&buf, len_ptr);
if(buf.len == -1) {
return false;
}
- // Answer section: _protocol._transport local PTR IN 3600 name._protocol._transport
- buf_check_uint16(&buf, 0xc00c); // _protocol._transport.local
+ // Check the PTR record: _protocol._transport.local PTR IN 3600 name._protocol._transport.local
+ buf_check_uint16(&buf, 0xc000 | protocol_offset);
buf_check_uint16(&buf, 0xc); // PTR
- buf_check_uint16(&buf, 0x1); // IN
+ buf_check_uint16(&buf, 0x8001); // IN (flush)
buf_check_uint32(&buf, 3600); // TTL
- const uint8_t *len_ptr = buf_check_len_start(&buf);
- uint16_t full_name = buf.ptr - data; // remember start of full name
- *name = buf_get_label(&buf);
- buf_check_uint16(&buf, 0xc00c); // _protocol._transport.local
+ len_ptr = buf_check_len_start(&buf);
+ buf_check_uint16(&buf, 0xc000 | full_name);
buf_check_len_end(&buf, len_ptr);
if(buf.len == -1) {
// Check the SRV record: name._protocol._transport.local SRV IN 120 0 0 port name.local
buf_check_uint16(&buf, 0xc000 | full_name);
buf_check_uint16(&buf, 0x21); // SRV
- buf_check_uint16(&buf, 0x1); // IN
+ buf_check_uint16(&buf, 0x8001); // IN (flush)
buf_check_uint32(&buf, 120); // TTL
len_ptr = buf_check_len_start(&buf);
buf_check_uint16(&buf, 0); // priority
buf_check_uint16(&buf, 0); // weight
*port = buf_get_uint16(&buf); // port
buf_check_label(&buf, *name);
- buf_check_uint16(&buf, 0xc000 | local);
- buf_check_len_end(&buf, len_ptr);
-
- if(buf.len == -1) {
- return false;
- }
-
- // Check the TXT records: name._protocol._transport.local TXT IN 3600 key=value...
- buf_check_uint16(&buf, 0xc000 | full_name);
- buf_check_uint16(&buf, 0x10); // TXT
- buf_check_uint16(&buf, 0x1); // IN
- buf_check_uint32(&buf, 3600); // TTL
- len_ptr = buf_check_len_start(&buf);
-
- for(int i = 0; i < nkeys; i++) {
- buf_get_kvp(&buf, keys[i], &values[i]);
- }
-
+ buf_check_uint16(&buf, 0xc000 | local_offset);
buf_check_len_end(&buf, len_ptr);
// Done.
projects / meshlink / blobdiff