/*
protocol.c -- handle the meta-protocol, basic functions
Copyright (C) 1999-2005 Ivo Timmermans,
- 2000-2006 Guus Sliepen <guus@tinc-vpn.org>
+ 2000-2022 Guus Sliepen <guus@tinc-vpn.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.
-
- $Id$
+ 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 "system.h"
#include "conf.h"
#include "connection.h"
+#include "crypto.h"
#include "logger.h"
#include "meta.h"
#include "protocol.h"
#include "xalloc.h"
bool tunnelserver = false;
+bool strictsubnets = false;
+bool experimental = true;
-/* Jumptable for the request handlers */
-
-static bool (*request_handlers[])(connection_t *) = {
- id_h, metakey_h, challenge_h, chal_reply_h, ack_h,
- status_h, error_h, termreq_h,
- ping_h, pong_h,
- add_subnet_h, del_subnet_h,
- add_edge_h, del_edge_h,
- key_changed_h, req_key_h, ans_key_h, tcppacket_h,
-};
-
-/* Request names */
+static inline bool is_valid_request(request_t req) {
+ return req > ALL && req < LAST;
+}
-static char (*request_name[]) = {
- "ID", "METAKEY", "CHALLENGE", "CHAL_REPLY", "ACK",
- "STATUS", "ERROR", "TERMREQ",
- "PING", "PONG",
- "ADD_SUBNET", "DEL_SUBNET",
- "ADD_EDGE", "DEL_EDGE", "KEY_CHANGED", "REQ_KEY", "ANS_KEY", "PACKET",
-};
+/* Request handlers */
+const request_entry_t *get_request_entry(request_t req) {
+ if(!is_valid_request(req)) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Invalid request %d", req);
+ return NULL;
+ }
-static avl_tree_t *past_request_tree;
+ // Prevent user from accessing the table directly to always have bound checks
+ static const request_entry_t request_entries[] = {
+ [ID] = {id_h, "ID"},
+ [METAKEY] = {metakey_h, "METAKEY"},
+ [CHALLENGE] = {challenge_h, "CHALLENGE"},
+ [CHAL_REPLY] = {chal_reply_h, "CHAL_REPLY"},
+ [ACK] = {ack_h, "ACK"},
+ [STATUS] = {NULL, "STATUS"},
+ [ERROR] = {NULL, "ERROR"},
+ [TERMREQ] = {termreq_h, "TERMREQ"},
+ [PING] = {ping_h, "PING"},
+ [PONG] = {pong_h, "PONG"},
+ [ADD_SUBNET] = {add_subnet_h, "ADD_SUBNET"},
+ [DEL_SUBNET] = {del_subnet_h, "DEL_SUBNET"},
+ [ADD_EDGE] = {add_edge_h, "ADD_EDGE"},
+ [DEL_EDGE] = {del_edge_h, "DEL_EDGE"},
+ [KEY_CHANGED] = {key_changed_h, "KEY_CHANGED"},
+ [REQ_KEY] = {req_key_h, "REQ_KEY"},
+ [ANS_KEY] = {ans_key_h, "ANS_KEY"},
+ [PACKET] = {tcppacket_h, "PACKET"},
+ [CONTROL] = {control_h, "CONTROL"},
+ /* Not "real" requests yet */
+ [REQ_PUBKEY] = {NULL, "REQ_PUBKEY"},
+ [ANS_PUBKEY] = {NULL, "ANS_PUBKEY"},
+ [SPTPS_PACKET] = {sptps_tcppacket_h, "SPTPS_PACKET"},
+ [UDP_INFO] = {udp_info_h, "UDP_INFO"},
+ [MTU_INFO] = {mtu_info_h, "MTU_INFO"},
+ };
+ return &request_entries[req];
+}
-bool check_id(const char *id)
-{
- for(; *id; id++)
- if(!isalnum(*id) && *id != '_')
- return false;
+static int past_request_compare(const past_request_t *a, const past_request_t *b) {
+ return strcmp(a->request, b->request);
+}
- return true;
+static void free_past_request(past_request_t *r) {
+ if(r) {
+ free((char *)r->request);
+ free(r);
+ }
}
+static splay_tree_t past_request_tree = {
+ .compare = (splay_compare_t) past_request_compare,
+ .delete = (splay_action_t) free_past_request,
+};
+
/* Generic request routines - takes care of logging and error
detection as well */
-bool send_request(connection_t *c, const char *format, ...)
-{
+bool send_request(connection_t *c, const char *format, ...) {
va_list args;
- char buffer[MAXBUFSIZE];
- int len, request;
-
- cp();
+ char request[MAXBUFSIZE];
+ int len;
/* Use vsnprintf instead of vxasprintf: faster, no memory
fragmentation, cleanup is automatic, and there is a limit on the
input buffer anyway */
va_start(args, format);
- len = vsnprintf(buffer, MAXBUFSIZE, format, args);
+ len = vsnprintf(request, sizeof(request), format, args);
+ request[sizeof(request) - 1] = 0;
va_end(args);
- if(len < 0 || len > MAXBUFSIZE - 1) {
- logger(LOG_ERR, _("Output buffer overflow while sending request to %s (%s)"),
- c->name, c->hostname);
+ if(len < 0 || (size_t)len > sizeof(request) - 1) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Output buffer overflow while sending request to %s (%s)",
+ c->name, c->hostname);
return false;
}
- ifdebug(PROTOCOL) {
- sscanf(buffer, "%d", &request);
- ifdebug(META)
- logger(LOG_DEBUG, _("Sending %s to %s (%s): %s"),
- request_name[request], c->name, c->hostname, buffer);
- else
- logger(LOG_DEBUG, _("Sending %s to %s (%s)"), request_name[request],
- c->name, c->hostname);
- }
+ int id = atoi(request);
+ logger(DEBUG_META, LOG_DEBUG, "Sending %s to %s (%s): %s", get_request_entry(id)->name, c->name, c->hostname, request);
- buffer[len++] = '\n';
+ request[len++] = '\n';
- if(c == broadcast) {
- broadcast_meta(NULL, buffer, len);
+ if(c == everyone) {
+ broadcast_meta(NULL, request, len);
return true;
- } else
- return send_meta(c, buffer, len);
-}
-
-void forward_request(connection_t *from)
-{
- int request;
-
- cp();
-
- ifdebug(PROTOCOL) {
- sscanf(from->buffer, "%d", &request);
- ifdebug(META)
- logger(LOG_DEBUG, _("Forwarding %s from %s (%s): %s"),
- request_name[request], from->name, from->hostname,
- from->buffer);
- else
- logger(LOG_DEBUG, _("Forwarding %s from %s (%s)"),
- request_name[request], from->name, from->hostname);
+ } else {
+ if(id) {
+ return send_meta(c, request, len);
+ } else {
+ send_meta_raw(c, request, len);
+ return true;
+ }
}
+}
- from->buffer[from->reqlen - 1] = '\n';
+void forward_request(connection_t *from, const char *request) {
+ logger(DEBUG_META, LOG_DEBUG, "Forwarding %s from %s (%s): %s", get_request_entry(atoi(request))->name, from->name, from->hostname, request);
- broadcast_meta(from, from->buffer, from->reqlen);
+ // Create a temporary newline-terminated copy of the request
+ size_t len = strlen(request);
+ const size_t tmplen = len + 1;
+ char *tmp = alloca(tmplen);
+ memcpy(tmp, request, len);
+ tmp[len] = '\n';
+ broadcast_meta(from, tmp, tmplen);
}
-bool receive_request(connection_t *c)
-{
- int request;
+bool receive_request(connection_t *c, const char *request) {
+ if(c->outgoing && proxytype == PROXY_HTTP && c->allow_request == ID) {
+ if(!request[0] || request[0] == '\r') {
+ return true;
+ }
- cp();
+ if(!strncasecmp(request, "HTTP/1.1 ", 9)) {
+ if(!strncmp(request + 9, "200", 3)) {
+ logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Proxy request granted");
+ return true;
+ } else {
+ logger(DEBUG_ALWAYS, LOG_DEBUG, "Proxy request rejected: %s", request + 9);
+ return false;
+ }
+ }
+ }
- if(sscanf(c->buffer, "%d", &request) == 1) {
- if((request < 0) || (request >= LAST) || !request_handlers[request]) {
- ifdebug(META)
- logger(LOG_DEBUG, _("Unknown request from %s (%s): %s"),
- c->name, c->hostname, c->buffer);
- else
- logger(LOG_ERR, _("Unknown request from %s (%s)"),
- c->name, c->hostname);
+ int reqno = atoi(request);
+ if(reqno || *request == '0') {
+ if(!is_valid_request(reqno) || !get_request_entry(reqno)->handler) {
+ logger(DEBUG_META, LOG_DEBUG, "Unknown request from %s (%s): %s", c->name, c->hostname, request);
return false;
- } else {
- ifdebug(PROTOCOL) {
- ifdebug(META)
- logger(LOG_DEBUG, _("Got %s from %s (%s): %s"),
- request_name[request], c->name, c->hostname,
- c->buffer);
- else
- logger(LOG_DEBUG, _("Got %s from %s (%s)"),
- request_name[request], c->name, c->hostname);
- }
}
- if((c->allow_request != ALL) && (c->allow_request != request)) {
- logger(LOG_ERR, _("Unauthorized request from %s (%s)"), c->name,
- c->hostname);
+ const request_entry_t *entry = get_request_entry(reqno);
+ logger(DEBUG_META, LOG_DEBUG, "Got %s from %s (%s): %s", entry->name, c->name, c->hostname, request);
+
+ if((c->allow_request != ALL) && (c->allow_request != reqno)) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Unauthorized request from %s (%s)", c->name, c->hostname);
return false;
}
- if(!request_handlers[request](c)) {
+ if(!entry->handler(c, request)) {
/* Something went wrong. Probably scriptkiddies. Terminate. */
- logger(LOG_ERR, _("Error while processing %s from %s (%s)"),
- request_name[request], c->name, c->hostname);
+ if(reqno != TERMREQ) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Error while processing %s from %s (%s)", entry->name, c->name, c->hostname);
+ }
+
return false;
}
} else {
- logger(LOG_ERR, _("Bogus data received from %s (%s)"),
- c->name, c->hostname);
+ logger(DEBUG_ALWAYS, LOG_ERR, "Bogus data received from %s (%s)", c->name, c->hostname);
return false;
}
return true;
}
-static int past_request_compare(const past_request_t *a, const past_request_t *b)
-{
- return strcmp(a->request, b->request);
-}
-
-static void free_past_request(past_request_t *r)
-{
- cp();
-
- if(r->request)
- free(r->request);
+static timeout_t past_request_timeout;
- free(r);
-}
-
-void init_requests(void)
-{
- cp();
+static void age_past_requests(void *data) {
+ (void)data;
+ int left = 0, deleted = 0;
- past_request_tree = avl_alloc_tree((avl_compare_t) past_request_compare, (avl_action_t) free_past_request);
-}
+ for splay_each(past_request_t, p, &past_request_tree) {
+ if(p->firstseen + pinginterval <= now.tv_sec) {
+ splay_delete_node(&past_request_tree, node), deleted++;
+ } else {
+ left++;
+ }
+ }
-void exit_requests(void)
-{
- cp();
+ if(left || deleted) {
+ logger(DEBUG_SCARY_THINGS, LOG_DEBUG, "Aging past requests: deleted %d, left %d", deleted, left);
+ }
- avl_delete_tree(past_request_tree);
+ if(left)
+ timeout_set(&past_request_timeout, &(struct timeval) {
+ 10, jitter()
+ });
}
-bool seen_request(char *request)
-{
+bool seen_request(const char *request) {
past_request_t *new, p = {0};
- cp();
-
p.request = request;
- if(avl_search(past_request_tree, &p)) {
- ifdebug(SCARY_THINGS) logger(LOG_DEBUG, _("Already seen request"));
+ if(splay_search(&past_request_tree, &p)) {
+ logger(DEBUG_SCARY_THINGS, LOG_DEBUG, "Already seen request");
return true;
} else {
new = xmalloc(sizeof(*new));
new->request = xstrdup(request);
- new->firstseen = now;
- avl_insert(past_request_tree, new);
+ new->firstseen = now.tv_sec;
+ splay_insert(&past_request_tree, new);
+ timeout_add(&past_request_timeout, age_past_requests, NULL, &(struct timeval) {
+ 10, jitter()
+ });
return false;
}
}
-void age_past_requests(void)
-{
- avl_node_t *node, *next;
- past_request_t *p;
- int left = 0, deleted = 0;
-
- cp();
-
- for(node = past_request_tree->head; node; node = next) {
- next = node->next;
- p = node->data;
-
- if(p->firstseen + pinginterval < now)
- avl_delete_node(past_request_tree, node), deleted++;
- else
- left++;
- }
+void exit_requests(void) {
+ splay_empty_tree(&past_request_tree);
- if(left || deleted)
- ifdebug(SCARY_THINGS) logger(LOG_DEBUG, _("Aging past requests: deleted %d, left %d"),
- deleted, left);
+ timeout_del(&past_request_timeout);
}
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