meta.c -- handle the meta communication
Copyright (C) 2000-2009 Guus Sliepen <guus@tinc-vpn.org>,
2000-2005 Ivo Timmermans
+ 2006 Scott Lamb <slamb@slamb.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
#include "system.h"
-#include <openssl/err.h>
-#include <openssl/evp.h>
-
-#include "avl_tree.h"
+#include "splay_tree.h"
+#include "cipher.h"
#include "connection.h"
#include "logger.h"
#include "meta.h"
#include "utils.h"
#include "xalloc.h"
-bool send_meta(connection_t *c, const char *buffer, int length)
-{
- int outlen;
- int result;
-
- cp();
-
+bool send_meta(connection_t *c, const char *buffer, int length) {
if(!c) {
- logger(LOG_ERR, _("send_meta() called with NULL pointer!"));
+ logger(LOG_ERR, "send_meta() called with NULL pointer!");
abort();
}
- ifdebug(META) logger(LOG_DEBUG, _("Sending %d bytes of metadata to %s (%s)"), length,
+ ifdebug(META) logger(LOG_DEBUG, "Sending %d bytes of metadata to %s (%s)", length,
c->name, c->hostname);
- if(!c->outbuflen)
- c->last_flushed_time = now;
-
- /* Find room in connection's buffer */
- if(length + c->outbuflen > c->outbufsize) {
- c->outbufsize = length + c->outbuflen;
- c->outbuf = xrealloc(c->outbuf, c->outbufsize);
- }
-
- if(length + c->outbuflen + c->outbufstart > c->outbufsize) {
- memmove(c->outbuf, c->outbuf + c->outbufstart, c->outbuflen);
- c->outbufstart = 0;
- }
-
/* Add our data to buffer */
if(c->status.encryptout) {
- result = EVP_EncryptUpdate(c->outctx, (unsigned char *)c->outbuf + c->outbufstart + c->outbuflen,
- &outlen, (unsigned char *)buffer, length);
- if(!result || outlen < length) {
- logger(LOG_ERR, _("Error while encrypting metadata to %s (%s): %s"),
- c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL));
- return false;
- } else if(outlen > length) {
- logger(LOG_EMERG, _("Encrypted data too long! Heap corrupted!"));
- abort();
- }
- c->outbuflen += outlen;
- } else {
- memcpy(c->outbuf + c->outbufstart + c->outbuflen, buffer, length);
- c->outbuflen += length;
- }
-
- return true;
-}
-
-bool flush_meta(connection_t *c)
-{
- int result;
-
- ifdebug(META) logger(LOG_DEBUG, _("Flushing %d bytes to %s (%s)"),
- c->outbuflen, c->name, c->hostname);
-
- while(c->outbuflen) {
- result = send(c->socket, c->outbuf + c->outbufstart, c->outbuflen, 0);
- if(result <= 0) {
- if(!errno || errno == EPIPE) {
- ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection closed by %s (%s)"),
- c->name, c->hostname);
- } else if(errno == EINTR) {
- continue;
-#ifdef EWOULDBLOCK
- } else if(errno == EWOULDBLOCK) {
- ifdebug(CONNECTIONS) logger(LOG_DEBUG, _("Flushing %d bytes to %s (%s) would block"),
- c->outbuflen, c->name, c->hostname);
- return true;
-#endif
- } else {
- logger(LOG_ERR, _("Flushing meta data to %s (%s) failed: %s"), c->name,
- c->hostname, strerror(errno));
- }
+ char outbuf[length];
+ size_t outlen = length;
+ if(!cipher_encrypt(&c->outcipher, buffer, length, outbuf, &outlen, false) || outlen != length) {
+ logger(LOG_ERR, "Error while encrypting metadata to %s (%s)",
+ c->name, c->hostname);
return false;
}
-
- c->outbufstart += result;
- c->outbuflen -= result;
+
+ write(c->socket, outbuf, length);
+ } else {
+ write(c->socket, buffer, length);
}
- c->outbufstart = 0; /* avoid unnecessary memmoves */
return true;
}
-void broadcast_meta(connection_t *from, const char *buffer, int length)
-{
- avl_node_t *node;
+void broadcast_meta(connection_t *from, const char *buffer, int length) {
+ splay_node_t *node;
connection_t *c;
- cp();
-
for(node = connection_tree->head; node; node = node->next) {
c = node->data;
}
}
-bool receive_meta(connection_t *c)
-{
- int oldlen, i, result;
- int lenin, lenout, reqlen;
- bool decrypted = false;
- char inbuf[MAXBUFSIZE];
+static bool process_meta(connection_t *c, char *reqbuf, int *len) {
+ while(*len) {
+ if(c->tcplen) {
+ if(c->tcplen > *len)
+ break;
- cp();
+ mutex_lock(&mutex);
+ receive_tcppacket(c, reqbuf, c->tcplen);
+ mutex_unlock(&mutex);
- /* Strategy:
- - Read as much as possible from the TCP socket in one go.
- - Decrypt it.
- - Check if a full request is in the input buffer.
- - If yes, process request and remove it from the buffer,
- then check again.
- - If not, keep stuff in buffer and exit.
- */
+ memmove(reqbuf, reqbuf, *len - c->tcplen);
+ *len -= c->tcplen;
+ } else {
+ char *end = memchr(reqbuf, '\n', *len);
+ if(!end)
+ break;
+ else
+ *end++ = 0;
- lenin = recv(c->socket, c->buffer + c->buflen, MAXBUFSIZE - c->buflen, 0);
+ mutex_lock(&mutex);
+ bool success = receive_request(c, reqbuf);
+ mutex_unlock(&mutex);
- if(lenin <= 0) {
- if(!lenin || !errno) {
- ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection closed by %s (%s)"),
- c->name, c->hostname);
- } else if(errno == EINTR)
- return true;
- else
- logger(LOG_ERR, _("Metadata socket read error for %s (%s): %s"),
- c->name, c->hostname, strerror(errno));
+ if(!success)
+ return false;
- return false;
+ memmove(reqbuf, end, *len - (end - reqbuf));
+ *len -= end - reqbuf;
+ }
}
- oldlen = c->buflen;
- c->buflen += lenin;
-
- while(lenin > 0) {
- /* Decrypt */
+ return true;
+}
+
+bool receive_meta(connection_t *c) {
+ int inlen;
+ int reqlen = 0;
+ char inbuf[MAXBUFSIZE];
+ char reqbuf[MAXBUFSIZE];
- if(c->status.decryptin && !decrypted) {
- result = EVP_DecryptUpdate(c->inctx, (unsigned char *)inbuf, &lenout, (unsigned char *)c->buffer + oldlen, lenin);
- if(!result || lenout != lenin) {
- logger(LOG_ERR, _("Error while decrypting metadata from %s (%s): %s"),
- c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL));
- return false;
- }
- memcpy(c->buffer + oldlen, inbuf, lenin);
- decrypted = true;
- }
+ /* Strategy:
+ - Read as much as possible from the TCP socket in one go.
+ - Decrypt it if necessary.
+ - Check if a full request is in the request buffer.
+ - If yes, process request and remove it from the buffer, then check again.
+ - If not, try to read more.
+ */
- /* Are we receiving a TCPpacket? */
+ while(true) {
+ inlen = recv(c->socket, inbuf, sizeof inbuf - reqlen, 0);
- if(c->tcplen) {
- if(c->tcplen <= c->buflen) {
- receive_tcppacket(c, c->buffer, c->tcplen);
-
- c->buflen -= c->tcplen;
- lenin -= c->tcplen - oldlen;
- memmove(c->buffer, c->buffer + c->tcplen, c->buflen);
- oldlen = 0;
- c->tcplen = 0;
+ if(inlen <= 0) {
+ if(!inlen || !errno) {
+ ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Connection closed by %s (%s)",
+ c->name, c->hostname);
+ } else if(sockwouldblock(sockerrno))
continue;
- } else {
- break;
- }
+ else
+ logger(LOG_ERR, "Metadata socket read error for %s (%s): %s",
+ c->name, c->hostname, sockstrerror(sockerrno));
+ return false;
}
- /* Otherwise we are waiting for a request */
-
- reqlen = 0;
+ while(inlen) {
+ if(!c->status.decryptin) {
+ char *end = memchr(inbuf, '\n', inlen);
+ if(!end)
+ end = inbuf + inlen;
+ else
+ end++;
+ memcpy(reqbuf + reqlen, inbuf, end - inbuf);
+ reqlen += end - inbuf;
+
+ if(!process_meta(c, reqbuf, &reqlen))
+ return false;
+
+ memmove(inbuf, end, inlen - (end - inbuf));
+ inlen -= end - inbuf;
+ } else {
+ size_t outlen = inlen;
- for(i = oldlen; i < c->buflen; i++) {
- if(c->buffer[i] == '\n') {
- c->buffer[i] = '\0'; /* replace end-of-line by end-of-string so we can use sscanf */
- reqlen = i + 1;
- break;
- }
- }
+ if(!cipher_decrypt(&c->incipher, inbuf, inlen, reqbuf + reqlen, &outlen, false) || inlen != outlen) {
+ logger(LOG_ERR, "Error while decrypting metadata from %s (%s)", c->name, c->hostname);
+ return false;
+ }
- if(reqlen) {
- c->reqlen = reqlen;
- if(!receive_request(c))
- return false;
+ reqlen += inlen;
+ inlen = 0;
- c->buflen -= reqlen;
- lenin -= reqlen - oldlen;
- memmove(c->buffer, c->buffer + reqlen, c->buflen);
- oldlen = 0;
- continue;
- } else {
- break;
+ if(!process_meta(c, reqbuf, &reqlen))
+ return false;
+ }
}
}
-
- if(c->buflen >= MAXBUFSIZE) {
- logger(LOG_ERR, _("Metadata read buffer overflow for %s (%s)"),
- c->name, c->hostname);
- return false;
- }
-
- c->last_ping_time = now;
-
- return true;
}