--- /dev/null
+// This file is Copyright its original authors, visible in version control
+// history.
+//
+// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
+// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
+// You may not use this file except in accordance with one or both of these
+// licenses.
+
+/**
+ * This file implements what you need to get networking up with LDK using
+ * standard POSIX APIs. Its not particularly effecient (in fact quite the
+ * opposite) but should be more than sufficient for most use-cases.
+ */
+
+#include "ldk_net.h"
+
+#include <lightning.h>
+
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <pthread.h>
+#include <poll.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stddef.h>
+
+#ifndef MSG_NOSIGNAL
+#define MSG_NOSIGNAL 0
+#define IS_BSD
+#endif
+
+#define MAX_CONNS 1024
+struct SocketHandler {
+ const struct LDKPeerManager *ldk_peer_manager;
+ pthread_t socket_thread;
+ bool should_exit;
+ int pipefds[2];
+ // pollfds ands sockcount may only be written to with a lock on
+ // sockets_mutex.
+ // sockcount mut always be the number of sockets in pollfds
+ // Items in pollfds may only be removed in the socket_thread, other threads
+ // may only append new file descriptors at the end (via register_socket).
+ pthread_mutex_t sockets_mutex;
+ struct pollfd pollfds[MAX_CONNS];
+ nfds_t sockcount;
+};
+
+int register_socket(struct SocketHandler* handler, int fd, int is_listen_sock) {
+ int fd_flags = fcntl(fd, F_GETFL, 0);
+ if (fd_flags < 0) return -1;
+ if (fcntl(fd, F_SETFL, fd_flags | O_NONBLOCK) == -1) return -1;
+
+ if (!is_listen_sock) {
+ int opt = 1;
+ if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, (void*)&opt, sizeof(opt))) return -1;
+#ifdef IS_BSD
+ if (setsockopt(fd, SOL_SOCKET, SO_NOSIGPIPE, (void*)&opt, sizeof(opt))) return -1;
+#endif
+ }
+
+ int lockres = pthread_mutex_lock(&handler->sockets_mutex);
+ assert(lockres == 0);
+
+ handler->pollfds[handler->sockcount].fd = fd;
+ handler->pollfds[handler->sockcount].events = POLLIN;
+ handler->pollfds[handler->sockcount].revents = 0;
+ handler->sockcount++;
+ assert(handler->sockcount <= MAX_CONNS);
+
+ lockres = pthread_mutex_unlock(&handler->sockets_mutex);
+ assert(lockres == 0);
+
+ uint8_t dummy = 0;
+ write(handler->pipefds[1], &dummy, 1);
+
+ return 0;
+}
+
+struct Descriptor {
+ struct SocketHandler *handler;
+ int fd;
+};
+
+static uintptr_t sock_send_data(void* desc, struct LDKu8slice data, bool resume_read) {
+ struct Descriptor *descriptor = (struct Descriptor*)desc;
+ ssize_t write_count = send(descriptor->fd, data.data, data.datalen, MSG_NOSIGNAL);
+ bool pause_read = false;
+ if (write_count <= 0) {
+ if (errno == EAGAIN || errno == EWOULDBLOCK) {
+ pause_read = true;
+ write_count = 0;
+ } else {
+ shutdown(descriptor->fd, SHUT_RDWR);
+ uint8_t dummy = 0;
+ write(descriptor->handler->pipefds[1], &dummy, 1);
+ return 0;
+ }
+ } else if (write_count < data.datalen) {
+ pause_read = true;
+ }
+ if (pause_read || resume_read) {
+ int lockres = pthread_mutex_lock(&descriptor->handler->sockets_mutex);
+ assert(lockres == 0);
+ for (int i = 0; i < descriptor->handler->sockcount; i++) {
+ if (descriptor->handler->pollfds[i].fd == descriptor->fd) {
+ if (pause_read) {
+ descriptor->handler->pollfds[i].events &= POLLIN;
+ descriptor->handler->pollfds[i].events |= POLLOUT;
+ } else {
+ descriptor->handler->pollfds[i].events |= POLLIN;
+ }
+ break;
+ }
+ }
+ lockres = pthread_mutex_unlock(&descriptor->handler->sockets_mutex);
+ assert(lockres == 0);
+ uint8_t dummy = 0;
+ write(descriptor->handler->pipefds[1], &dummy, 1);
+ }
+
+ return write_count;
+}
+static void sock_disconnect(void* desc) {
+ struct Descriptor *descriptor = (struct Descriptor*)desc;
+ shutdown(descriptor->fd, SHUT_RDWR);
+ uint8_t dummy = 0;
+ write(descriptor->handler->pipefds[1], &dummy, 1);
+}
+static bool sock_eq(const void* desc, const struct LDKSocketDescriptor *other_arg) {
+ const struct Descriptor *descriptor = (const struct Descriptor*)desc;
+ const struct Descriptor *other_descriptor = (const struct Descriptor*)other_arg->this_arg;
+ return descriptor->fd == other_descriptor->fd;
+}
+static uint64_t sock_hash(const void* desc) {
+ const struct Descriptor *descriptor = (const struct Descriptor*)desc;
+ return (uint64_t)descriptor->fd;
+}
+static void* sock_clone(const void* desc) {
+ const struct Descriptor *descriptor = (const struct Descriptor*)desc;
+ struct Descriptor *new_desc = malloc(sizeof(struct Descriptor));
+ new_desc->handler = descriptor->handler;
+ new_desc->fd = descriptor->fd;
+ return new_desc;
+}
+static void sock_free(void* desc) {
+ free(desc);
+}
+
+static inline LDKSocketDescriptor get_descriptor(struct SocketHandler *handler, int fd) {
+ struct Descriptor *desc = malloc(sizeof(struct Descriptor));
+ desc->handler = handler;
+ desc->fd = fd;
+ LDKSocketDescriptor ret = {
+ .this_arg = (void*)desc,
+ .send_data = sock_send_data,
+ .disconnect_socket = sock_disconnect,
+ .eq = sock_eq,
+ .hash = sock_hash,
+ .clone = sock_clone,
+ .free = sock_free,
+ };
+ return ret;
+}
+
+static void *sock_thread_fn(void* arg) {
+ struct SocketHandler *handler = (struct SocketHandler*) arg;
+
+ int lockres;
+ struct pollfd pollfds[MAX_CONNS + 1];
+ int fd_count;
+
+ int close_socks[MAX_CONNS];
+ int close_socks_count = 0;
+
+ uint8_t readbuf[8192];
+
+ while (!handler->should_exit) {
+ {
+ lockres = pthread_mutex_lock(&handler->sockets_mutex);
+ assert(lockres == 0);
+ memcpy(pollfds, handler->pollfds, sizeof(struct pollfd) * handler->sockcount);
+ fd_count = handler->sockcount;
+ lockres = pthread_mutex_unlock(&handler->sockets_mutex);
+ assert(lockres == 0);
+ }
+ pollfds[fd_count].fd = handler->pipefds[0];
+ pollfds[fd_count].events = POLLIN;
+ fd_count++;
+
+ int pollres = poll(pollfds, fd_count, 10000);
+ assert(pollres != -1);
+ close_socks_count = 0;
+
+ read(pollfds[fd_count-1].fd, readbuf, sizeof(readbuf)); // Empty out the pipe
+
+ if (pollres > 0) {
+ for (int i = 0; i < fd_count - 1; i++) {
+ if (pollfds[i].revents) {
+ LDKSocketDescriptor descriptor = get_descriptor(handler, pollfds[i].fd);
+ if (pollfds[i].revents & POLLIN) {
+ int readlen = read(pollfds[i].fd, readbuf, sizeof(readbuf));
+ if (readlen < 0) {
+ if (errno == EAGAIN || errno == EWOULDBLOCK) {
+ // Spurious wake.
+ } else if (errno == EINVAL || errno == ENOTCONN) {
+ // Assume we're a listening socket!
+ int newfd = accept(pollfds[i].fd, NULL, NULL);
+ if (newfd >= 0) {
+ // Received a new connection, register it!
+ LDKSocketDescriptor new_descriptor = get_descriptor(handler, newfd);
+ LDKCResult_NonePeerHandleErrorZ con_res = PeerManager_new_inbound_connection(handler->ldk_peer_manager, new_descriptor);
+ if (con_res.result_ok) {
+ if (register_socket(handler, newfd, 0))
+ shutdown(newfd, SHUT_RDWR);
+ } else
+ close(newfd);
+ CResult_NonePeerHandleErrorZ_free(con_res);
+ } else {
+ // Maybe it wasn't a listening socket, disconnect!
+ close_socks[close_socks_count++] = i;
+ }
+ } else {
+ close_socks[close_socks_count++] = i;
+ }
+ } else if (readlen == 0) {
+ // EOF
+ close_socks[close_socks_count++] = i;
+ } else {
+ LDKu8slice data = {
+ .data = readbuf,
+ .datalen = readlen,
+ };
+ LDKCResult_boolPeerHandleErrorZ res = PeerManager_read_event(handler->ldk_peer_manager, &descriptor, data);
+ if (res.result_ok) {
+ if (*res.contents.result) {
+ lockres = pthread_mutex_lock(&handler->sockets_mutex);
+ assert(lockres == 0);
+ assert(handler->pollfds[i - 1].fd == pollfds[i].fd); // Only we change fd order!
+ handler->pollfds[i - 1].events &= POLLIN;
+ handler->pollfds[i - 1].events |= POLLOUT;
+ lockres = pthread_mutex_unlock(&handler->sockets_mutex);
+ assert(lockres == 0);
+ }
+ } else {
+ close_socks[close_socks_count++] = i;
+ }
+ CResult_boolPeerHandleErrorZ_free(res);
+ }
+ }
+ if (pollfds[i].revents & POLLOUT) {
+ LDKCResult_NonePeerHandleErrorZ res = PeerManager_write_buffer_space_avail(handler->ldk_peer_manager, &descriptor);
+ if (!res.result_ok) {
+ close_socks[close_socks_count++] = i;
+ }
+ CResult_NonePeerHandleErrorZ_free(res);
+ }
+ SocketDescriptor_free(descriptor);
+ }
+ }
+ }
+
+ // We only do the actual socket disconnect handling in this thread,
+ // other threads may append to pollfds and call shutdown().
+ // Thus, in this thread, we first call socket_disconnected for each
+ // socket we're gonna remove, then we walk the sockets and close() each
+ // which should be disconnecting, shifting the remaining sockets down
+ // as we walk.
+ for (int i = 0; i < close_socks_count; i++) {
+ LDKSocketDescriptor descriptor = get_descriptor(handler, handler->pollfds[close_socks[i]].fd);
+ PeerManager_socket_disconnected(handler->ldk_peer_manager, &descriptor);
+ SocketDescriptor_free(descriptor);
+ }
+
+ lockres = pthread_mutex_lock(&handler->sockets_mutex);
+ assert(lockres == 0);
+ int close_idx = 0;
+ for (int i = 0; close_socks_count != 0 && i < handler->sockcount; i++) {
+ if (close_idx < close_socks_count && close_socks[close_idx] == i) {
+ close(handler->pollfds[i].fd);
+ close_idx++;
+ } else {
+ handler->pollfds[i-close_idx] = handler->pollfds[i];
+ }
+ }
+ assert(close_idx == close_socks_count);
+ handler->sockcount -= close_socks_count;
+ lockres = pthread_mutex_unlock(&handler->sockets_mutex);
+ assert(lockres == 0);
+
+ PeerManager_process_events(handler->ldk_peer_manager);
+ }
+
+ lockres = pthread_mutex_lock(&handler->sockets_mutex);
+ assert(lockres == 0);
+ for (int i = 0; i < handler->sockcount; i++) {
+ LDKSocketDescriptor descriptor = get_descriptor(handler, handler->pollfds[i].fd);
+ PeerManager_socket_disconnected(handler->ldk_peer_manager, &descriptor);
+ SocketDescriptor_free(descriptor);
+ }
+
+ for (int i = 0; i < handler->sockcount; i++) {
+ close(handler->pollfds[i].fd);
+ }
+ close(handler->pipefds[0]);
+ close(handler->pipefds[1]);
+ handler->sockcount = 0;
+ lockres = pthread_mutex_unlock(&handler->sockets_mutex);
+ assert(lockres == 0);
+
+ return NULL;
+}
+
+
+void* init_socket_handling(const struct LDKPeerManager *NONNULL_PTR ldk_peer_manager) {
+ struct SocketHandler *handler = NULL;
+
+ handler = (struct SocketHandler*) calloc(1, sizeof(struct SocketHandler));
+ if (!handler) goto err;
+ handler->pipefds[0] = -1;
+ handler->pipefds[1] = -1;
+
+ handler->ldk_peer_manager = ldk_peer_manager;
+ handler->should_exit = false;
+
+ if (pipe(handler->pipefds) != 0) goto err;
+
+ int fd_flags = fcntl(handler->pipefds[0], F_GETFL, 0);
+ if (fd_flags < 0) goto err;
+ if (fcntl(handler->pipefds[0], F_SETFL, fd_flags | O_NONBLOCK) == -1) goto err;
+
+ if (pthread_mutex_init(&handler->sockets_mutex, NULL) != 0) goto err;
+ if (pthread_create(&handler->socket_thread, NULL, sock_thread_fn, handler) != 0) {
+ pthread_mutex_destroy(&handler->sockets_mutex);
+ goto err;
+ }
+
+ return handler;
+
+err:
+ if (handler) {
+ if (handler->pipefds[0] != -1) close(handler->pipefds[0]);
+ if (handler->pipefds[1] != -1) close(handler->pipefds[1]);
+ free(handler);
+ }
+ return NULL;
+}
+
+void interrupt_socket_handling(void* arg) {
+ struct SocketHandler *handler = (struct SocketHandler*) arg;
+ handler->should_exit = true;
+ uint8_t dummy = 0;
+ write(handler->pipefds[1], &dummy, 1);
+ void *retval;
+ int ret = pthread_join(handler->socket_thread, &retval);
+ assert(ret == 0);
+ free(handler);
+}
+
+int socket_connect(void* arg, LDKPublicKey pubkey, struct sockaddr *addr, size_t addrlen) {
+ struct SocketHandler *handler = (struct SocketHandler*) arg;
+
+ int fd = socket(addr->sa_family, SOCK_STREAM, 0);
+ if (fd < 0) return -1;
+
+ struct timeval timeout;
+ timeout.tv_sec = 1;
+ timeout.tv_usec = 0;
+ if (setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &timeout, sizeof(timeout))) return -2;
+ if (connect(fd, addr, addrlen)) return -3;
+ timeout.tv_sec = 120;
+ if (setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &timeout, sizeof(timeout))) return -3;
+
+ if (register_socket(handler, fd, 0)) return -4;
+
+ LDKSocketDescriptor descriptor = get_descriptor(handler, fd);
+ LDKCResult_CVec_u8ZPeerHandleErrorZ con_res = PeerManager_new_outbound_connection(handler->ldk_peer_manager, pubkey, descriptor);
+ if (con_res.result_ok) {
+ ssize_t write_count = send(fd, con_res.contents.result->data, con_res.contents.result->datalen, MSG_NOSIGNAL);
+ if (write_count != con_res.contents.result->datalen)
+ shutdown(fd, SHUT_RDWR);
+ } else {
+ shutdown(fd, SHUT_RDWR);
+ }
+ CResult_CVec_u8ZPeerHandleErrorZ_free(con_res);
+
+ return 0;
+}
+
+int socket_bind(void* arg, struct sockaddr *addr, socklen_t addrlen) {
+ struct SocketHandler *handler = (struct SocketHandler*) arg;
+ int fd = socket(addr->sa_family, SOCK_STREAM, 0);
+ if (fd < 0) return -1;
+
+ int reuseon = 1;
+ if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &reuseon, sizeof(reuseon))) return -2;
+
+ if (bind(fd, addr, addrlen)) return -3;
+ if (listen(fd, 32)) return -4;
+
+ if (register_socket(handler, fd, 1)) return -5;
+
+ return 0;
+}
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