_ Git - ldk-c-bindings/blob - ldk-net/ldk_net.c

   1 // This file is Copyright its original authors, visible in version control
   2 // history.
   3 //
   4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
   5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
   7 // You may not use this file except in accordance with one or both of these
   8 // licenses.
   9
  10 /**
  11  * This file implements what you need to get networking up with LDK using
  12  * standard POSIX APIs. Its not particularly effecient (in fact quite the
  13  * opposite) but should be more than sufficient for most use-cases.
  14  */
  15
  16 #include "ldk_net.h"
  17
  18 #include <lightning.h>
  19
  20 #include <sys/socket.h>
  21 #include <sys/time.h>
  22 #include <netinet/in.h>
  23 #include <netinet/tcp.h>
  24 #include <pthread.h>
  25 #include <poll.h>
  26 #include <unistd.h>
  27 #include <fcntl.h>
  28 #include <errno.h>
  29 #include <assert.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <stddef.h>
  33
  34 #ifndef MSG_NOSIGNAL
  35 #define MSG_NOSIGNAL 0
  36 #define IS_BSD
  37 #endif
  38
  39 #define MAX_CONNS 1024
  40 struct SocketHandler {
  41         const struct LDKPeerManager *ldk_peer_manager;
  42         pthread_t socket_thread;
  43         bool should_exit;
  44         int pipefds[2];
  45         // pollfds ands sockcount may only be written to with a lock on
  46         // sockets_mutex.
  47         // sockcount mut always be the number of sockets in pollfds
  48         // Items in pollfds may only be removed in the socket_thread, other threads
  49         // may only append new file descriptors at the end (via register_socket).
  50         pthread_mutex_t sockets_mutex;
  51         struct pollfd pollfds[MAX_CONNS];
  52         nfds_t sockcount;
  53 };
  54
  55 int register_socket(struct SocketHandler* handler, int fd, int is_listen_sock) {
  56         int fd_flags = fcntl(fd, F_GETFL, 0);
  57         if (fd_flags < 0) return -1;
  58         if (fcntl(fd, F_SETFL, fd_flags | O_NONBLOCK) == -1) return -1;
  59
  60         if (!is_listen_sock) {
  61                 int opt = 1;
  62                 if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, (void*)&opt, sizeof(opt))) return -1;
  63 #ifdef IS_BSD
  64                 if (setsockopt(fd, SOL_SOCKET, SO_NOSIGPIPE, (void*)&opt, sizeof(opt))) return -1;
  65 #endif
  66         }
  67
  68         int lockres = pthread_mutex_lock(&handler->sockets_mutex);
  69         assert(lockres == 0);
  70
  71         handler->pollfds[handler->sockcount].fd = fd;
  72         handler->pollfds[handler->sockcount].events = POLLIN;
  73         handler->pollfds[handler->sockcount].revents = 0;
  74         handler->sockcount++;
  75         assert(handler->sockcount <= MAX_CONNS);
  76
  77         lockres = pthread_mutex_unlock(&handler->sockets_mutex);
  78         assert(lockres == 0);
  79
  80         uint8_t dummy = 0;
  81         write(handler->pipefds[1], &dummy, 1);
  82
  83         return 0;
  84 }
  85
  86 struct Descriptor {
  87         struct SocketHandler *handler;
  88         int fd;
  89 };
  90
  91 static uintptr_t sock_send_data(void* desc, struct LDKu8slice data, bool resume_read) {
  92         struct Descriptor *descriptor = (struct Descriptor*)desc;
  93         ssize_t write_count = send(descriptor->fd, data.data, data.datalen, MSG_NOSIGNAL);
  94         bool pause_read = false;
  95         if (write_count <= 0) {
  96                 if (errno == EAGAIN || errno == EWOULDBLOCK) {
  97                         pause_read = true;
  98                         write_count = 0;
  99                 } else {
 100                         shutdown(descriptor->fd, SHUT_RDWR);
 101                         uint8_t dummy = 0;
 102                         write(descriptor->handler->pipefds[1], &dummy, 1);
 103                         return 0;
 104                 }
 105         } else if (write_count < data.datalen) {
 106                 pause_read = true;
 107         }
 108         if (pause_read || resume_read) {
 109                 int lockres = pthread_mutex_lock(&descriptor->handler->sockets_mutex);
 110                 assert(lockres == 0);
 111                 for (int i = 0; i < descriptor->handler->sockcount; i++) {
 112                         if (descriptor->handler->pollfds[i].fd == descriptor->fd) {
 113                                 if (pause_read) {
 114                                         descriptor->handler->pollfds[i].events &= POLLIN;
 115                                         descriptor->handler->pollfds[i].events |= POLLOUT;
 116                                 } else {
 117                                         descriptor->handler->pollfds[i].events |= POLLIN;
 118                                 }
 119                                 break;
 120                         }
 121                 }
 122                 lockres = pthread_mutex_unlock(&descriptor->handler->sockets_mutex);
 123                 assert(lockres == 0);
 124                 uint8_t dummy = 0;
 125                 write(descriptor->handler->pipefds[1], &dummy, 1);
 126         }
 127
 128         return write_count;
 129 }
 130 static void sock_disconnect(void* desc) {
 131         struct Descriptor *descriptor = (struct Descriptor*)desc;
 132         shutdown(descriptor->fd, SHUT_RDWR);
 133         uint8_t dummy = 0;
 134         write(descriptor->handler->pipefds[1], &dummy, 1);
 135 }
 136 static bool sock_eq(const void* desc, const struct LDKSocketDescriptor *other_arg) {
 137         const struct Descriptor *descriptor = (const struct Descriptor*)desc;
 138         const struct Descriptor *other_descriptor = (const struct Descriptor*)other_arg->this_arg;
 139         return descriptor->fd == other_descriptor->fd;
 140 }
 141 static uint64_t sock_hash(const void* desc) {
 142         const struct Descriptor *descriptor = (const struct Descriptor*)desc;
 143         return (uint64_t)descriptor->fd;
 144 }
 145 static void* sock_clone(const void* desc) {
 146         const struct Descriptor *descriptor = (const struct Descriptor*)desc;
 147         struct Descriptor *new_desc = malloc(sizeof(struct Descriptor));
 148         new_desc->handler = descriptor->handler;
 149         new_desc->fd = descriptor->fd;
 150         return new_desc;
 151 }
 152 static void sock_free(void* desc) {
 153         free(desc);
 154 }
 155
 156 static inline LDKSocketDescriptor get_descriptor(struct SocketHandler *handler, int fd) {
 157         struct Descriptor *desc = malloc(sizeof(struct Descriptor));
 158         desc->handler = handler;
 159         desc->fd = fd;
 160         LDKSocketDescriptor ret = {
 161                 .this_arg = (void*)desc,
 162                 .send_data = sock_send_data,
 163                 .disconnect_socket = sock_disconnect,
 164                 .eq = sock_eq,
 165                 .hash = sock_hash,
 166                 .clone = sock_clone,
 167                 .free = sock_free,
 168         };
 169         return ret;
 170 }
 171
 172 static void *sock_thread_fn(void* arg) {
 173         struct SocketHandler *handler = (struct SocketHandler*) arg;
 174
 175         int lockres;
 176         struct pollfd pollfds[MAX_CONNS + 1];
 177         int fd_count;
 178
 179         int close_socks[MAX_CONNS];
 180         int close_socks_count = 0;
 181
 182         uint8_t readbuf[8192];
 183
 184         while (!handler->should_exit) {
 185                 {
 186                         lockres = pthread_mutex_lock(&handler->sockets_mutex);
 187                         assert(lockres == 0);
 188                         memcpy(pollfds, handler->pollfds, sizeof(struct pollfd) * handler->sockcount);
 189                         fd_count = handler->sockcount;
 190                         lockres = pthread_mutex_unlock(&handler->sockets_mutex);
 191                         assert(lockres == 0);
 192                 }
 193                 pollfds[fd_count].fd = handler->pipefds[0];
 194                 pollfds[fd_count].events = POLLIN;
 195                 fd_count++;
 196
 197                 int pollres = poll(pollfds, fd_count, 10000);
 198                 assert(pollres != -1);
 199                 close_socks_count = 0;
 200
 201                 read(pollfds[fd_count-1].fd, readbuf, sizeof(readbuf)); // Empty out the pipe
 202
 203                 if (pollres > 0) {
 204                         for (int i = 0; i < fd_count - 1; i++) {
 205                                 if (pollfds[i].revents) {
 206                                         LDKSocketDescriptor descriptor = get_descriptor(handler, pollfds[i].fd);
 207                                         if (pollfds[i].revents & POLLIN) {
 208                                                 int readlen = read(pollfds[i].fd, readbuf, sizeof(readbuf));
 209                                                 if (readlen < 0) {
 210                                                         if (errno == EAGAIN || errno == EWOULDBLOCK) {
 211                                                                 // Spurious wake.
 212                                                         } else if (errno == EINVAL || errno == ENOTCONN) {
 213                                                                 // Assume we're a listening socket!
 214                                                                 int newfd = accept(pollfds[i].fd, NULL, NULL);
 215                                                                 if (newfd >= 0) {
 216                                                                         // Received a new connection, register it!
 217                                                                         LDKSocketDescriptor new_descriptor = get_descriptor(handler, newfd);
 218                                                                         LDKCResult_NonePeerHandleErrorZ con_res = PeerManager_new_inbound_connection(handler->ldk_peer_manager, new_descriptor);
 219                                                                         if (con_res.result_ok) {
 220                                                                                 if (register_socket(handler, newfd, 0))
 221                                                                                         shutdown(newfd, SHUT_RDWR);
 222                                                                         } else
 223                                                                                 close(newfd);
 224                                                                         CResult_NonePeerHandleErrorZ_free(con_res);
 225                                                                 } else {
 226                                                                         // Maybe it wasn't a listening socket, disconnect!
 227                                                                         close_socks[close_socks_count++] = i;
 228                                                                 }
 229                                                         } else {
 230                                                                 close_socks[close_socks_count++] = i;
 231                                                         }
 232                                                 } else if (readlen == 0) {
 233                                                         // EOF
 234                                                         close_socks[close_socks_count++] = i;
 235                                                 } else {
 236                                                         LDKu8slice data = {
 237                                                                 .data = readbuf,
 238                                                                 .datalen = readlen,
 239                                                         };
 240                                                         LDKCResult_boolPeerHandleErrorZ res = PeerManager_read_event(handler->ldk_peer_manager, &descriptor, data);
 241                                                         if (res.result_ok) {
 242                                                                 if (*res.contents.result) {
 243                                                                         lockres = pthread_mutex_lock(&handler->sockets_mutex);
 244                                                                         assert(lockres == 0);
 245                                                                         assert(handler->pollfds[i - 1].fd == pollfds[i].fd); // Only we change fd order!
 246                                                                         handler->pollfds[i - 1].events &= POLLIN;
 247                                                                         handler->pollfds[i - 1].events |= POLLOUT;
 248                                                                         lockres = pthread_mutex_unlock(&handler->sockets_mutex);
 249                                                                         assert(lockres == 0);
 250                                                                 }
 251                                                         } else {
 252                                                                 close_socks[close_socks_count++] = i;
 253                                                         }
 254                                                         CResult_boolPeerHandleErrorZ_free(res);
 255                                                 }
 256                                         }
 257                                         if (pollfds[i].revents & POLLOUT) {
 258                                                 LDKCResult_NonePeerHandleErrorZ res = PeerManager_write_buffer_space_avail(handler->ldk_peer_manager, &descriptor);
 259                                                 if (!res.result_ok) {
 260                                                         close_socks[close_socks_count++] = i;
 261                                                 }
 262                                                 CResult_NonePeerHandleErrorZ_free(res);
 263                                         }
 264                                         SocketDescriptor_free(descriptor);
 265                                 }
 266                         }
 267                 }
 268
 269                 // We only do the actual socket disconnect handling in this thread,
 270                 // other threads may append to pollfds and call shutdown().
 271                 // Thus, in this thread, we first call socket_disconnected for each
 272                 // socket we're gonna remove, then we walk the sockets and close() each
 273                 // which should be disconnecting, shifting the remaining sockets down
 274                 // as we walk.
 275                 for (int i = 0; i < close_socks_count; i++) {
 276                         LDKSocketDescriptor descriptor = get_descriptor(handler, handler->pollfds[close_socks[i]].fd);
 277                         PeerManager_socket_disconnected(handler->ldk_peer_manager, &descriptor);
 278                         SocketDescriptor_free(descriptor);
 279                 }
 280
 281                 lockres = pthread_mutex_lock(&handler->sockets_mutex);
 282                 assert(lockres == 0);
 283                 int close_idx = 0;
 284                 for (int i = 0; close_socks_count != 0 && i < handler->sockcount; i++) {
 285                         if (close_idx < close_socks_count && close_socks[close_idx] == i) {
 286                                 close(handler->pollfds[i].fd);
 287                                 close_idx++;
 288                         } else {
 289                                 handler->pollfds[i-close_idx] = handler->pollfds[i];
 290                         }
 291                 }
 292                 assert(close_idx == close_socks_count);
 293                 handler->sockcount -= close_socks_count;
 294                 lockres = pthread_mutex_unlock(&handler->sockets_mutex);
 295                 assert(lockres == 0);
 296
 297                 PeerManager_process_events(handler->ldk_peer_manager);
 298         }
 299
 300         lockres = pthread_mutex_lock(&handler->sockets_mutex);
 301         assert(lockres == 0);
 302         for (int i = 0; i < handler->sockcount; i++) {
 303                 LDKSocketDescriptor descriptor = get_descriptor(handler, handler->pollfds[i].fd);
 304                 PeerManager_socket_disconnected(handler->ldk_peer_manager, &descriptor);
 305                 SocketDescriptor_free(descriptor);
 306         }
 307
 308         for (int i = 0; i < handler->sockcount; i++) {
 309                 close(handler->pollfds[i].fd);
 310         }
 311         close(handler->pipefds[0]);
 312         close(handler->pipefds[1]);
 313         handler->sockcount = 0;
 314         lockres = pthread_mutex_unlock(&handler->sockets_mutex);
 315         assert(lockres == 0);
 316
 317         return NULL;
 318 }
 319
 320
 321 void* init_socket_handling(const struct LDKPeerManager *NONNULL_PTR ldk_peer_manager) {
 322         struct SocketHandler *handler = NULL;
 323
 324         handler = (struct SocketHandler*) calloc(1, sizeof(struct SocketHandler));
 325         if (!handler) goto err;
 326         handler->pipefds[0] = -1;
 327         handler->pipefds[1] = -1;
 328
 329         handler->ldk_peer_manager = ldk_peer_manager;
 330         handler->should_exit = false;
 331
 332         if (pipe(handler->pipefds) != 0) goto err;
 333
 334         int fd_flags = fcntl(handler->pipefds[0], F_GETFL, 0);
 335         if (fd_flags < 0) goto err;
 336         if (fcntl(handler->pipefds[0], F_SETFL, fd_flags | O_NONBLOCK) == -1) goto err;
 337
 338         if (pthread_mutex_init(&handler->sockets_mutex, NULL) != 0) goto err;
 339         if (pthread_create(&handler->socket_thread, NULL, sock_thread_fn, handler) != 0) {
 340                 pthread_mutex_destroy(&handler->sockets_mutex);
 341                 goto err;
 342         }
 343
 344         return handler;
 345
 346 err:
 347         if (handler) {
 348                 if (handler->pipefds[0] != -1) close(handler->pipefds[0]);
 349                 if (handler->pipefds[1] != -1) close(handler->pipefds[1]);
 350                 free(handler);
 351         }
 352         return NULL;
 353 }
 354
 355 void interrupt_socket_handling(void* arg) {
 356         struct SocketHandler *handler = (struct SocketHandler*) arg;
 357         handler->should_exit = true;
 358         uint8_t dummy = 0;
 359         write(handler->pipefds[1], &dummy, 1);
 360         void *retval;
 361         int ret = pthread_join(handler->socket_thread, &retval);
 362         assert(ret == 0);
 363         free(handler);
 364 }
 365
 366 int socket_connect(void* arg, LDKPublicKey pubkey, struct sockaddr *addr, size_t addrlen) {
 367         struct SocketHandler *handler = (struct SocketHandler*) arg;
 368
 369         int fd = socket(addr->sa_family, SOCK_STREAM, 0);
 370         if (fd < 0) return -1;
 371
 372         struct timeval timeout;
 373         timeout.tv_sec = 1;
 374         timeout.tv_usec = 0;
 375         if (setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &timeout, sizeof(timeout))) return -2;
 376         if (connect(fd, addr, addrlen)) return -3;
 377         timeout.tv_sec = 120;
 378         if (setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &timeout, sizeof(timeout))) return -3;
 379
 380         if (register_socket(handler, fd, 0)) return -4;
 381
 382         LDKSocketDescriptor descriptor = get_descriptor(handler, fd);
 383         LDKCResult_CVec_u8ZPeerHandleErrorZ con_res = PeerManager_new_outbound_connection(handler->ldk_peer_manager, pubkey, descriptor);
 384         if (con_res.result_ok) {
 385                 ssize_t write_count = send(fd, con_res.contents.result->data, con_res.contents.result->datalen, MSG_NOSIGNAL);
 386                 if (write_count != con_res.contents.result->datalen)
 387                         shutdown(fd, SHUT_RDWR);
 388         } else {
 389                 shutdown(fd, SHUT_RDWR);
 390         }
 391         CResult_CVec_u8ZPeerHandleErrorZ_free(con_res);
 392
 393         return 0;
 394 }
 395
 396 int socket_bind(void* arg, struct sockaddr *addr, socklen_t addrlen) {
 397         struct SocketHandler *handler = (struct SocketHandler*) arg;
 398         int fd = socket(addr->sa_family, SOCK_STREAM, 0);
 399         if (fd < 0) return -1;
 400
 401         int reuseon = 1;
 402         if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &reuseon, sizeof(reuseon))) return -2;
 403
 404         if (bind(fd, addr, addrlen)) return -3;
 405         if (listen(fd, 32)) return -4;
 406
 407         if (register_socket(handler, fd, 1)) return -5;
 408
 409         return 0;
 410 }