/*
meta.c -- handle the meta communication
- Copyright (C) 2000 Guus Sliepen <guus@sliepen.warande.net>,
- 2000 Ivo Timmermans <itimmermans@bigfoot.com>
+ Copyright (C) 2000-2017 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
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-
- $Id: meta.c,v 1.1.2.12 2000/11/20 19:12:12 guus Exp $
+ You should have received a copy of the GNU General Public License along
+ with this program; if not, write to the Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
-#include "config.h"
-#include <utils.h>
-
-#include <errno.h>
-#include <syslog.h>
-#include <sys/signal.h>
-#include <unistd.h>
-#include <string.h>
-/* This line must be below the rest for FreeBSD */
-#include <sys/socket.h>
+#include "system.h"
-#ifdef HAVE_OPENSSL_EVP_H
-# include <openssl/evp.h>
-#else
-# include <evp.h>
-#endif
+#include <openssl/err.h>
+#include <openssl/evp.h>
-#include "net.h"
+#include "avl_tree.h"
#include "connection.h"
-#include "system.h"
+#include "logger.h"
+#include "meta.h"
+#include "net.h"
#include "protocol.h"
+#include "proxy.h"
+#include "utils.h"
+#include "xalloc.h"
+
+bool send_meta(connection_t *c, const char *buffer, int length) {
+ int outlen;
+ int result;
+
+ 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) {
+ /* Check encryption limits */
+ if((uint64_t)length > c->outbudget) {
+ ifdebug(META) logger(LOG_ERR, "Byte limit exceeded for encryption to %s (%s)", c->name, c->hostname);
+ return false;
+ } else {
+ c->outbudget -= length;
+ }
+
+ result = EVP_EncryptUpdate(c->outctx, (unsigned char *)c->outbuf + c->outbufstart + c->outbuflen,
+ &outlen, (unsigned char *)buffer, length);
-int send_meta(connection_t *cl, char *buffer, int length)
-{
- char outbuf[MAXBUFSIZE];
- char *bufp;
- int outlen;
-cp
- if(debug_lvl >= DEBUG_META)
- syslog(LOG_DEBUG, _("Sending %d bytes of metadata to %s (%s): %s"), length,
- cl->name, cl->hostname, buffer);
-
- buffer[length-1]='\n';
-
- if(cl->status.encryptout)
- {
- EVP_EncryptUpdate(cl->cipher_outctx, outbuf, &outlen, buffer, length);
- bufp = outbuf;
- length = outlen;
- }
- else
- bufp = buffer;
-
- if(write(cl->meta_socket, bufp, length) < 0)
- {
- syslog(LOG_ERR, _("Sending meta data to %s (%s) failed: %m"), cl->name, cl->hostname);
- return -1;
- }
-cp
- return 0;
+ 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;
+ } else if(sockwouldblock(sockerrno)) {
+ ifdebug(META) logger(LOG_DEBUG, "Flushing %d bytes to %s (%s) would block",
+ c->outbuflen, c->name, c->hostname);
+ return true;
+ } else {
+ logger(LOG_ERR, "Flushing meta data to %s (%s) failed: %s", c->name,
+ c->hostname, sockstrerror(sockerrno));
+ }
+
+ return false;
+ }
+
+ c->outbufstart += result;
+ c->outbuflen -= result;
+ }
+
+ c->outbufstart = 0; /* avoid unnecessary memmoves */
+ return true;
}
-void broadcast_meta(connection_t *cl, char *buffer, int length)
-{
- rbl_t *rbl;
- connection_t *p;
-cp
- RBL_FOREACH(connection_tree, rbl)
- {
- p = (connection_t *)rbl->data;
- if(p != cl && p->status.meta && p->status.active)
- send_meta(p, buffer, length);
- }
-cp
+void broadcast_meta(connection_t *from, const char *buffer, int length) {
+ avl_node_t *node;
+ connection_t *c;
+
+ for(node = connection_tree->head; node; node = node->next) {
+ c = node->data;
+
+ if(c != from && c->status.active) {
+ send_meta(c, buffer, length);
+ }
+ }
}
-int receive_meta(connection_t *cl)
-{
- int x, l = sizeof(x);
- int oldlen, i;
- int lenin = 0;
- char inbuf[MAXBUFSIZE];
- char *bufp;
-cp
- if(getsockopt(cl->meta_socket, SOL_SOCKET, SO_ERROR, &x, &l) < 0)
- {
- syslog(LOG_ERR, _("This is a bug: %s:%d: %d:%m %s (%s)"), __FILE__, __LINE__, cl->meta_socket,
- cl->name, cl->hostname);
- return -1;
- }
- if(x)
- {
- syslog(LOG_ERR, _("Metadata socket error for %s (%s): %s"),
- cl->name, cl->hostname, strerror(x));
- return -1;
- }
-
- if(cl->status.decryptin)
- bufp = inbuf;
- else
- bufp = cl->buffer + cl->buflen;
-
- lenin = read(cl->meta_socket, bufp, MAXBUFSIZE - cl->buflen);
-
- if(lenin<=0)
- {
- if(errno==EINTR)
- return 0;
- if(errno==0)
- {
- if(debug_lvl >= DEBUG_CONNECTIONS)
- syslog(LOG_NOTICE, _("Connection closed by %s (%s)"),
- cl->name, cl->hostname);
- }
- else
- syslog(LOG_ERR, _("Metadata socket read error for %s (%s): %m"),
- cl->name, cl->hostname);
- return -1;
- }
-
- if(cl->status.decryptin)
- {
- EVP_DecryptUpdate(cl->cipher_inctx, cl->buffer + cl->buflen, &lenin, inbuf, lenin);
- }
-
- oldlen = cl->buflen;
- cl->buflen += lenin;
-
- for(;;)
- {
- cl->reqlen = 0;
-
- for(i = oldlen; i < cl->buflen; i++)
- {
- if(cl->buffer[i] == '\n')
- {
- cl->buffer[i] = 0; /* replace end-of-line by end-of-string so we can use sscanf */
- cl->reqlen = i + 1;
- break;
- }
- }
-
- if(cl->reqlen)
- {
- if(debug_lvl >= DEBUG_META)
- syslog(LOG_DEBUG, _("Got request from %s (%s): %s"),
- cl->name, cl->hostname, cl->buffer);
-
- if(receive_request(cl))
- return -1;
-
- cl->buflen -= cl->reqlen;
- memmove(cl->buffer, cl->buffer + cl->reqlen, cl->buflen);
- oldlen = 0;
- }
- else
- {
- break;
- }
- }
-
- if(cl->buflen >= MAXBUFSIZE)
- {
- syslog(LOG_ERR, _("Metadata read buffer overflow for %s (%s)"),
- cl->name, cl->hostname);
- return -1;
- }
-
- cl->last_ping_time = time(NULL);
-cp
- return 0;
+bool receive_meta(connection_t *c) {
+ int oldlen, i, result;
+ int lenin, lenout, reqlen;
+ bool decrypted = false;
+ char inbuf[MAXBUFSIZE];
+
+ /* 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.
+ */
+
+ lenin = recv(c->socket, c->buffer + c->buflen, MAXBUFSIZE - c->buflen, 0);
+
+ if(lenin <= 0) {
+ if(!lenin || !errno) {
+ ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Connection closed by %s (%s)",
+ c->name, c->hostname);
+ } else if(sockwouldblock(sockerrno)) {
+ return true;
+ } else
+ logger(LOG_ERR, "Metadata socket read error for %s (%s): %s",
+ c->name, c->hostname, sockstrerror(sockerrno));
+
+ return false;
+ }
+
+ oldlen = c->buflen;
+ c->buflen += lenin;
+
+ while(lenin > 0) {
+ reqlen = 0;
+
+ /* Is it proxy metadata? */
+
+ if(c->allow_request == PROXY) {
+ reqlen = receive_proxy_meta(c);
+
+ if(reqlen < 0) {
+ return false;
+ }
+
+ goto consume;
+ }
+
+ /* Decrypt */
+
+ if(c->status.decryptin && !decrypted) {
+ /* Check decryption limits */
+ if((uint64_t)lenin > c->inbudget) {
+ ifdebug(META) logger(LOG_ERR, "Byte limit exceeded for decryption from %s (%s)", c->name, c->hostname);
+ return false;
+ } else {
+ c->inbudget -= lenin;
+ }
+
+ 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;
+ }
+
+ /* Are we receiving a TCPpacket? */
+
+ if(c->tcplen) {
+ if(c->tcplen <= c->buflen) {
+ if(c->allow_request != ALL) {
+ logger(LOG_ERR, "Got unauthorized TCP packet from %s (%s)", c->name, c->hostname);
+ return false;
+ }
+
+ receive_tcppacket(c, c->buffer, c->tcplen);
+ reqlen = c->tcplen;
+ c->tcplen = 0;
+ }
+ } else {
+ /* Otherwise we are waiting for a request */
+
+ 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 */
+ c->reqlen = reqlen = i + 1;
+ break;
+ }
+ }
+
+ if(reqlen && !receive_request(c)) {
+ return false;
+ }
+ }
+
+consume:
+
+ if(reqlen) {
+ c->buflen -= reqlen;
+ lenin -= reqlen - oldlen;
+ memmove(c->buffer, c->buffer + reqlen, c->buflen);
+ oldlen = 0;
+ continue;
+ } else {
+ break;
+ }
+ }
+
+ if(c->buflen >= MAXBUFSIZE) {
+ logger(LOG_ERR, "Metadata read buffer overflow for %s (%s)",
+ c->name, c->hostname);
+ return false;
+ }
+
+ return true;
}
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