Enforce maximum amount of bytes sent/received on meta-connections.

[tinc] / src / meta.c

diff --git a/src/meta.c b/src/meta.c
index 1c29fe9..4b35798 100644 (file)
--- a/src/meta.c
+++ b/src/meta.c
@@ -30,6 +30,10 @@
 #include "utils.h"
 #include "xalloc.h"
 
+#ifndef MIN
+#define MIN(x, y) (((x)<(y))?(x):(y))
+#endif
+
 bool send_meta_sptps(void *handle, uint8_t type, const void *buffer, size_t length) {
        connection_t *c = handle;
 
@@ -61,6 +65,13 @@ bool send_meta(connection_t *c, const char *buffer, int length) {
 #ifdef DISABLE_LEGACY
                return false;
 #else
+               if(length > c->outbudget) {
+                       logger(DEBUG_META, LOG_ERR, "Byte limit exceeded for encryption to %s (%s)", c->name, c->hostname);
+                       return false;
+               } else {
+                       c->outbudget -= length;
+               }
+
                size_t outlen = length;
 
                if(!cipher_encrypt(c->outcipher, buffer, length, buffer_prepare(&c->outbuf, length), &outlen, false) || outlen != length) {
@@ -78,6 +89,20 @@ bool send_meta(connection_t *c, const char *buffer, int length) {
        return true;
 }
 
+void send_meta_raw(connection_t *c, const char *buffer, int length) {
+       if(!c) {
+               logger(DEBUG_ALWAYS, LOG_ERR, "send_meta() called with NULL pointer!");
+               abort();
+       }
+
+       logger(DEBUG_META, LOG_DEBUG, "Sending %d bytes of raw metadata to %s (%s)", length,
+                          c->name, c->hostname);
+
+       buffer_add(&c->outbuf, buffer, length);
+
+       io_set(&c->io, IO_READ | IO_WRITE);
+}
+
 void broadcast_meta(connection_t *from, const char *buffer, int length) {
        for list_each(connection_t, c, connection_list)
                if(c != from && c->edge)
@@ -159,8 +184,33 @@ bool receive_meta(connection_t *c) {
        }
 
        do {
-               if(c->protocol_minor >= 2)
-                       return sptps_receive_data(&c->sptps, bufp, inlen);
+               /* Are we receiving a SPTPS packet? */
+
+               if(c->sptpslen) {
+                       int len = MIN(inlen, c->sptpslen - c->inbuf.len);
+                       buffer_add(&c->inbuf, bufp, len);
+
+                       char *sptpspacket = buffer_read(&c->inbuf, c->sptpslen);
+                       if(!sptpspacket)
+                               return true;
+
+                       if(!receive_tcppacket_sptps(c, sptpspacket, c->sptpslen))
+                               return false;
+                       c->sptpslen = 0;
+
+                       bufp += len;
+                       inlen -= len;
+                       continue;
+               }
+
+               if(c->protocol_minor >= 2) {
+                       int len = sptps_receive_data(&c->sptps, bufp, inlen);
+                       if(!len)
+                               return false;
+                       bufp += len;
+                       inlen -= len;
+                       continue;
+               }
 
                if(!c->status.decryptin) {
                        endp = memchr(bufp, '\n', inlen);
@@ -177,6 +227,13 @@ bool receive_meta(connection_t *c) {
 #ifdef DISABLE_LEGACY
                        return false;
 #else
+                       if(inlen > c->inbudget) {
+                               logger(DEBUG_META, LOG_ERR, "yte limit exceeded for decryption from %s (%s)", c->name, c->hostname);
+                               return false;
+                       } else {
+                               c->inbudget -= inlen;
+                       }
+
                        size_t outlen = inlen;
 
                        if(!cipher_decrypt(c->incipher, bufp, inlen, buffer_prepare(&c->inbuf, inlen), &outlen, false) || inlen != outlen) {