ubusd_main.c

   1 /*
   2  * Copyright (C) 2011-2014 Felix Fietkau <nbd@openwrt.org>
   3  *
   4  * SPDX-License-Identifier: LGPL-2.1-only
   5  */
   6
   7 #include <sys/socket.h>
   8 #include <sys/stat.h>
   9 #include <sys/types.h>
  10 #ifdef FreeBSD
  11 #include <sys/param.h>
  12 #endif
  13 #include <string.h>
  14 #include <syslog.h>
  15
  16 #include <libubox/usock.h>
  17
  18 #include "ubusd.h"
  19
  20 static struct ubus_msg_buf *ubus_msg_head(struct ubus_client *cl)
  21 {
  22         return cl->tx_queue[cl->txq_cur];
  23 }
  24
  25 static void ubus_msg_dequeue(struct ubus_client *cl)
  26 {
  27         struct ubus_msg_buf *ub = ubus_msg_head(cl);
  28
  29         if (!ub)
  30                 return;
  31
  32         ubus_msg_free(ub);
  33         cl->txq_ofs = 0;
  34         cl->tx_queue[cl->txq_cur] = NULL;
  35         cl->txq_cur = (cl->txq_cur + 1) % ARRAY_SIZE(cl->tx_queue);
  36 }
  37
  38 static void handle_client_disconnect(struct ubus_client *cl)
  39 {
  40         while (ubus_msg_head(cl))
  41                 ubus_msg_dequeue(cl);
  42
  43         ubusd_monitor_disconnect(cl);
  44         ubusd_proto_free_client(cl);
  45         if (cl->pending_msg_fd >= 0)
  46                 close(cl->pending_msg_fd);
  47         uloop_fd_delete(&cl->sock);
  48         close(cl->sock.fd);
  49         free(cl);
  50 }
  51
  52 static void client_cb(struct uloop_fd *sock, unsigned int events)
  53 {
  54         struct ubus_client *cl = container_of(sock, struct ubus_client, sock);
  55         uint8_t fd_buf[CMSG_SPACE(sizeof(int))] = { 0 };
  56         struct msghdr msghdr = { 0 };
  57         struct ubus_msg_buf *ub;
  58         static struct iovec iov;
  59         struct cmsghdr *cmsg;
  60         int *pfd;
  61
  62         msghdr.msg_iov = &iov,
  63         msghdr.msg_iovlen = 1,
  64         msghdr.msg_control = fd_buf;
  65         msghdr.msg_controllen = sizeof(fd_buf);
  66
  67         cmsg = CMSG_FIRSTHDR(&msghdr);
  68         cmsg->cmsg_type = SCM_RIGHTS;
  69         cmsg->cmsg_level = SOL_SOCKET;
  70         cmsg->cmsg_len = CMSG_LEN(sizeof(int));
  71
  72         pfd = (int *) CMSG_DATA(cmsg);
  73         msghdr.msg_controllen = cmsg->cmsg_len;
  74
  75         /* first try to tx more pending data */
  76         while ((ub = ubus_msg_head(cl))) {
  77                 ssize_t written;
  78
  79                 written = ubus_msg_writev(sock->fd, ub, cl->txq_ofs);
  80                 if (written < 0) {
  81                         switch(errno) {
  82                         case EINTR:
  83                         case EAGAIN:
  84                                 break;
  85                         default:
  86                                 goto disconnect;
  87                         }
  88                         break;
  89                 }
  90
  91                 cl->txq_ofs += written;
  92                 if (cl->txq_ofs < ub->len + sizeof(ub->hdr))
  93                         break;
  94
  95                 ubus_msg_dequeue(cl);
  96         }
  97
  98         /* prevent further ULOOP_WRITE events if we don't have data
  99          * to send anymore */
 100         if (!ubus_msg_head(cl) && (events & ULOOP_WRITE))
 101                 uloop_fd_add(sock, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 102
 103 retry:
 104         if (!sock->eof && cl->pending_msg_offset < (int) sizeof(cl->hdrbuf)) {
 105                 int offset = cl->pending_msg_offset;
 106                 int bytes;
 107
 108                 *pfd = -1;
 109
 110                 iov.iov_base = ((char *) &cl->hdrbuf) + offset;
 111                 iov.iov_len = sizeof(cl->hdrbuf) - offset;
 112
 113                 if (cl->pending_msg_fd < 0) {
 114                         msghdr.msg_control = fd_buf;
 115                         msghdr.msg_controllen = cmsg->cmsg_len;
 116                 } else {
 117                         msghdr.msg_control = NULL;
 118                         msghdr.msg_controllen = 0;
 119                 }
 120
 121                 bytes = recvmsg(sock->fd, &msghdr, 0);
 122                 if (bytes < 0)
 123                         goto out;
 124
 125                 if (*pfd >= 0)
 126                         cl->pending_msg_fd = *pfd;
 127
 128                 cl->pending_msg_offset += bytes;
 129                 if (cl->pending_msg_offset < (int) sizeof(cl->hdrbuf))
 130                         goto out;
 131
 132                 if (blob_pad_len(&cl->hdrbuf.data) > UBUS_MAX_MSGLEN)
 133                         goto disconnect;
 134
 135                 cl->pending_msg = ubus_msg_new(NULL, blob_raw_len(&cl->hdrbuf.data), false);
 136                 if (!cl->pending_msg)
 137                         goto disconnect;
 138
 139                 cl->hdrbuf.hdr.seq = be16_to_cpu(cl->hdrbuf.hdr.seq);
 140                 cl->hdrbuf.hdr.peer = be32_to_cpu(cl->hdrbuf.hdr.peer);
 141
 142                 memcpy(&cl->pending_msg->hdr, &cl->hdrbuf.hdr, sizeof(cl->hdrbuf.hdr));
 143                 memcpy(cl->pending_msg->data, &cl->hdrbuf.data, sizeof(cl->hdrbuf.data));
 144         }
 145
 146         ub = cl->pending_msg;
 147         if (ub) {
 148                 int offset = cl->pending_msg_offset - sizeof(ub->hdr);
 149                 int len = blob_raw_len(ub->data) - offset;
 150                 int bytes = 0;
 151
 152                 if (len > 0) {
 153                         bytes = read(sock->fd, (char *) ub->data + offset, len);
 154                         if (bytes <= 0)
 155                                 goto out;
 156                 }
 157
 158                 if (bytes < len) {
 159                         cl->pending_msg_offset += bytes;
 160                         goto out;
 161                 }
 162
 163                 /* accept message */
 164                 ub->fd = cl->pending_msg_fd;
 165                 cl->pending_msg_fd = -1;
 166                 cl->pending_msg_offset = 0;
 167                 cl->pending_msg = NULL;
 168                 ubusd_monitor_message(cl, ub, false);
 169                 ubusd_proto_receive_message(cl, ub);
 170                 goto retry;
 171         }
 172
 173 out:
 174         if (!sock->eof || ubus_msg_head(cl))
 175                 return;
 176
 177 disconnect:
 178         handle_client_disconnect(cl);
 179 }
 180
 181 static bool get_next_connection(int fd)
 182 {
 183         struct ubus_client *cl;
 184         int client_fd;
 185
 186         client_fd = accept(fd, NULL, 0);
 187         if (client_fd < 0) {
 188                 switch (errno) {
 189                 case ECONNABORTED:
 190                 case EINTR:
 191                         return true;
 192                 default:
 193                         return false;
 194                 }
 195         }
 196
 197         cl = ubusd_proto_new_client(client_fd, client_cb);
 198         if (cl)
 199                 uloop_fd_add(&cl->sock, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 200         else
 201                 close(client_fd);
 202
 203         return true;
 204 }
 205
 206 static void server_cb(struct uloop_fd *fd, unsigned int events)
 207 {
 208         bool next;
 209
 210         do {
 211                 next = get_next_connection(fd->fd);
 212         } while (next);
 213 }
 214
 215 static struct uloop_fd server_fd = {
 216         .cb = server_cb,
 217 };
 218
 219 static int usage(const char *progname)
 220 {
 221         fprintf(stderr, "Usage: %s [<options>]\n"
 222                 "Options: \n"
 223                 "  -A <path>:           Set the path to ACL files\n"
 224                 "  -s <socket>:         Set the unix domain socket to listen on\n"
 225                 "\n", progname);
 226         return 1;
 227 }
 228
 229 static void sighup_handler(int sig)
 230 {
 231         ubusd_acl_load();
 232 }
 233
 234 static void mkdir_sockdir()
 235 {
 236         char *ubus_sock_dir, *tmp;
 237
 238         ubus_sock_dir = strdup(UBUS_UNIX_SOCKET);
 239         tmp = strrchr(ubus_sock_dir, '/');
 240         if (tmp) {
 241                 *tmp = '\0';
 242                 mkdir(ubus_sock_dir, 0755);
 243         }
 244         free(ubus_sock_dir);
 245 }
 246
 247 int main(int argc, char **argv)
 248 {
 249         const char *ubus_socket = UBUS_UNIX_SOCKET;
 250         int ret = 0;
 251         int ch;
 252
 253         signal(SIGPIPE, SIG_IGN);
 254         signal(SIGHUP, sighup_handler);
 255
 256         openlog("ubusd", LOG_PID, LOG_DAEMON);
 257         uloop_init();
 258
 259         while ((ch = getopt(argc, argv, "A:s:")) != -1) {
 260                 switch (ch) {
 261                 case 's':
 262                         ubus_socket = optarg;
 263                         break;
 264                 case 'A':
 265                         ubusd_acl_dir = optarg;
 266                         break;
 267                 default:
 268                         return usage(argv[0]);
 269                 }
 270         }
 271
 272         mkdir_sockdir();
 273         unlink(ubus_socket);
 274         umask(0111);
 275         server_fd.fd = usock(USOCK_UNIX | USOCK_SERVER | USOCK_NONBLOCK, ubus_socket, NULL);
 276         if (server_fd.fd < 0) {
 277                 perror("usock");
 278                 ret = -1;
 279                 goto out;
 280         }
 281         uloop_fd_add(&server_fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 282         ubusd_acl_load();
 283
 284         uloop_run();
 285         unlink(ubus_socket);
 286
 287 out:
 288         uloop_done();
 289         return ret;
 290 }