2 protocol.c -- handle the meta-protocol, basic functions
3 Copyright (C) 2014-2017 Guus Sliepen <guus@meshlink.io>
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License along
16 with this program; if not, write to the Free Software Foundation, Inc.,
17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
23 #include "connection.h"
25 #include "meshlink_internal.h"
32 /* Jumptable for the request handlers */
34 static bool (*request_handlers[NUM_REQUESTS])(meshlink_handle_t *, connection_t *, const char *) = {
39 [TERMREQ] = termreq_h,
42 [ADD_EDGE] = add_edge_h,
43 [DEL_EDGE] = del_edge_h,
44 [KEY_CHANGED] = key_changed_h,
45 [REQ_KEY] = req_key_h,
46 [ANS_KEY] = ans_key_h,
47 [PACKET] = raw_packet_h,
52 static const char *request_name[NUM_REQUESTS] = {
57 [TERMREQ] = "TERMREQ",
60 [ADD_EDGE] = "ADD_EDGE",
61 [DEL_EDGE] = "DEL_EDGE",
62 [KEY_CHANGED] = "KEY_CHANGED",
63 [REQ_KEY] = "REQ_KEY",
64 [ANS_KEY] = "ANS_KEY",
68 bool check_id(const char *id) {
74 if(!isalnum(*id) && *id != '_' && *id != '-') {
81 /* Generic request routines - takes care of logging and error
84 bool send_request(meshlink_handle_t *mesh, connection_t *c, const submesh_t *s, const char *format, ...) {
89 logger(mesh, MESHLINK_ERROR, "Trying to send request to non-existing connection");
94 char request[MAXBUFSIZE];
97 /* Use vsnprintf instead of vxasprintf: faster, no memory
98 fragmentation, cleanup is automatic, and there is a limit on the
99 input buffer anyway */
101 va_start(args, format);
102 len = vsnprintf(request, MAXBUFSIZE, format, args);
105 if(len < 0 || len > MAXBUFSIZE - 1) {
106 logger(mesh, MESHLINK_ERROR, "Output buffer overflow while sending request to %s", c->name);
110 logger(mesh, MESHLINK_DEBUG, "Sending %s to %s: %s", request_name[atoi(request)], c->name, request);
112 request[len++] = '\n';
114 if(c == mesh->everyone) {
117 broadcast_submesh_meta(mesh, NULL, s, request, len);
119 broadcast_meta(mesh, NULL, request, len);
124 return send_meta(mesh, c, request, len);
128 void forward_request(meshlink_handle_t *mesh, connection_t *from, const submesh_t *s, const char *request) {
133 logger(mesh, MESHLINK_DEBUG, "Forwarding %s from %s: %s", request_name[atoi(request)], from->name, request);
135 // Create a temporary newline-terminated copy of the request
136 int len = strlen(request);
139 memcpy(tmp, request, len);
143 broadcast_submesh_meta(mesh, from, s, tmp, sizeof(tmp));
145 broadcast_meta(mesh, from, tmp, sizeof(tmp));
149 bool receive_request(meshlink_handle_t *mesh, connection_t *c, const char *request) {
152 int reqno = atoi(request);
154 if(reqno || *request == '0') {
155 if((reqno < 0) || (reqno >= NUM_REQUESTS) || !request_handlers[reqno]) {
156 logger(mesh, MESHLINK_DEBUG, "Unknown request from %s: %s", c->name, request);
159 logger(mesh, MESHLINK_DEBUG, "Got %s from %s: %s", request_name[reqno], c->name, request);
162 if((c->allow_request != ALL) && (c->allow_request != reqno) && (reqno != ERROR)) {
163 logger(mesh, MESHLINK_ERROR, "Unauthorized request from %s", c->name);
167 if(!request_handlers[reqno](mesh, c, request)) {
168 /* Something went wrong. Probably scriptkiddies. Terminate. */
170 logger(mesh, MESHLINK_ERROR, "Error while processing %s from %s", request_name[reqno], c->name);
174 logger(mesh, MESHLINK_ERROR, "Bogus data received from %s", c->name);
181 static int past_request_compare(const past_request_t *a, const past_request_t *b) {
182 return strcmp(a->request, b->request);
185 static void free_past_request(past_request_t *r) {
187 free((void *)r->request);
193 static const int request_timeout = 60;
195 static void age_past_requests(event_loop_t *loop, void *data) {
197 meshlink_handle_t *mesh = loop->data;
198 int left = 0, deleted = 0;
200 for splay_each(past_request_t, p, mesh->past_request_tree) {
201 if(p->firstseen + request_timeout <= mesh->loop.now.tv_sec) {
202 splay_delete_node(mesh->past_request_tree, splay_node), deleted++;
208 if(left || deleted) {
209 logger(mesh, MESHLINK_DEBUG, "Aging past requests: deleted %d, left %d", deleted, left);
213 timeout_set(&mesh->loop, &mesh->past_request_timeout, &(struct timespec) {
214 10, prng(mesh, TIMER_FUDGE)
219 bool seen_request(meshlink_handle_t *mesh, const char *request) {
223 past_request_t *new, p = {.request = request};
225 if(splay_search(mesh->past_request_tree, &p)) {
226 logger(mesh, MESHLINK_DEBUG, "Already seen request");
229 new = xmalloc(sizeof(*new));
230 new->request = xstrdup(request);
231 new->firstseen = mesh->loop.now.tv_sec;
233 if(!mesh->past_request_tree->head && mesh->past_request_timeout.cb) {
234 timeout_set(&mesh->loop, &mesh->past_request_timeout, &(struct timespec) {
235 10, prng(mesh, TIMER_FUDGE)
239 splay_insert(mesh->past_request_tree, new);
244 void init_requests(meshlink_handle_t *mesh) {
245 assert(!mesh->past_request_tree);
247 mesh->past_request_tree = splay_alloc_tree((splay_compare_t) past_request_compare, (splay_action_t) free_past_request);
248 timeout_add(&mesh->loop, &mesh->past_request_timeout, age_past_requests, NULL, &(struct timespec) {
253 void exit_requests(meshlink_handle_t *mesh) {
254 if(mesh->past_request_tree) {
255 splay_delete_tree(mesh->past_request_tree);
258 mesh->past_request_tree = NULL;
260 timeout_del(&mesh->loop, &mesh->past_request_timeout);