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 void handle_client_disconnect(struct ubus_client *cl)
  21 {
  22         struct ubus_msg_buf_list *ubl, *ubl2;
  23         list_for_each_entry_safe(ubl, ubl2, &cl->tx_queue, list)
  24                 ubus_msg_list_free(ubl);
  25
  26         ubusd_monitor_disconnect(cl);
  27         ubusd_proto_free_client(cl);
  28         if (cl->pending_msg_fd >= 0)
  29                 close(cl->pending_msg_fd);
  30         uloop_fd_delete(&cl->sock);
  31         close(cl->sock.fd);
  32         free(cl);
  33 }
  34
  35 static void ubus_client_cmd_free(struct ubus_client_cmd *cmd)
  36 {
  37         list_del(&cmd->list);
  38         ubus_msg_free(cmd->msg);
  39         free(cmd);
  40 }
  41
  42 static void ubus_client_cmd_queue_process(struct ubus_client *cl)
  43 {
  44         struct ubus_client_cmd *cmd, *tmp;
  45
  46         list_for_each_entry_safe(cmd, tmp, &cl->cmd_queue, list) {
  47                 int ret = ubusd_cmd_lookup(cl, cmd);
  48
  49                 /* Stop if the last command caused buffering again */
  50                 if (ret == -2)
  51                         break;
  52
  53                 ubus_client_cmd_free(cmd);
  54         }
  55 }
  56
  57 static void client_cb(struct uloop_fd *sock, unsigned int events)
  58 {
  59         struct ubus_client *cl = container_of(sock, struct ubus_client, sock);
  60         uint8_t fd_buf[CMSG_SPACE(sizeof(int))] = { 0 };
  61         struct msghdr msghdr = { 0 };
  62         struct ubus_msg_buf *ub;
  63         struct ubus_msg_buf_list *ubl, *ubl2;
  64         static struct iovec iov;
  65         struct cmsghdr *cmsg;
  66         int *pfd;
  67
  68         msghdr.msg_iov = &iov,
  69         msghdr.msg_iovlen = 1,
  70         msghdr.msg_control = fd_buf;
  71         msghdr.msg_controllen = sizeof(fd_buf);
  72
  73         cmsg = CMSG_FIRSTHDR(&msghdr);
  74         cmsg->cmsg_type = SCM_RIGHTS;
  75         cmsg->cmsg_level = SOL_SOCKET;
  76         cmsg->cmsg_len = CMSG_LEN(sizeof(int));
  77
  78         pfd = (int *) CMSG_DATA(cmsg);
  79         msghdr.msg_controllen = cmsg->cmsg_len;
  80
  81         /* first try to tx more pending data */
  82         list_for_each_entry_safe(ubl, ubl2, &cl->tx_queue, list) {
  83                 ssize_t written;
  84
  85                 ub = ubl->msg;
  86                 written = ubus_msg_writev(sock->fd, ub, cl->txq_ofs);
  87                 if (written < 0) {
  88                         switch(errno) {
  89                         case EINTR:
  90                         case EAGAIN:
  91                                 break;
  92                         default:
  93                                 goto disconnect;
  94                         }
  95                         break;
  96                 }
  97
  98                 cl->txq_ofs += written;
  99                 cl->txq_len -= written;
 100                 if (cl->txq_ofs < ub->len + sizeof(ub->hdr))
 101                         break;
 102
 103                 cl->txq_ofs = 0;
 104                 ubus_msg_list_free(ubl);
 105         }
 106
 107         if (list_empty(&cl->tx_queue) && (events & ULOOP_WRITE)) {
 108                 /* Process queued commands */
 109                 ubus_client_cmd_queue_process(cl);
 110
 111                 /* prevent further ULOOP_WRITE events if we don't have data
 112                  * to send anymore */
 113                 if (list_empty(&cl->tx_queue))
 114                         uloop_fd_add(sock, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 115         }
 116
 117 retry:
 118         if (!sock->eof && cl->pending_msg_offset < (int) sizeof(cl->hdrbuf)) {
 119                 int offset = cl->pending_msg_offset;
 120                 int bytes;
 121
 122                 *pfd = -1;
 123
 124                 iov.iov_base = ((char *) &cl->hdrbuf) + offset;
 125                 iov.iov_len = sizeof(cl->hdrbuf) - offset;
 126
 127                 if (cl->pending_msg_fd < 0) {
 128                         msghdr.msg_control = fd_buf;
 129                         msghdr.msg_controllen = cmsg->cmsg_len;
 130                 } else {
 131                         msghdr.msg_control = NULL;
 132                         msghdr.msg_controllen = 0;
 133                 }
 134
 135                 bytes = recvmsg(sock->fd, &msghdr, 0);
 136                 if (bytes < 0)
 137                         goto out;
 138
 139                 if (*pfd >= 0)
 140                         cl->pending_msg_fd = *pfd;
 141
 142                 cl->pending_msg_offset += bytes;
 143                 if (cl->pending_msg_offset < (int) sizeof(cl->hdrbuf))
 144                         goto out;
 145
 146                 if (blob_raw_len(&cl->hdrbuf.data) < sizeof(struct blob_attr))
 147                         goto disconnect;
 148                 if (blob_pad_len(&cl->hdrbuf.data) > UBUS_MAX_MSGLEN)
 149                         goto disconnect;
 150
 151                 cl->pending_msg = ubus_msg_new(NULL, blob_raw_len(&cl->hdrbuf.data), false);
 152                 if (!cl->pending_msg)
 153                         goto disconnect;
 154
 155                 cl->hdrbuf.hdr.seq = be16_to_cpu(cl->hdrbuf.hdr.seq);
 156                 cl->hdrbuf.hdr.peer = be32_to_cpu(cl->hdrbuf.hdr.peer);
 157
 158                 memcpy(&cl->pending_msg->hdr, &cl->hdrbuf.hdr, sizeof(cl->hdrbuf.hdr));
 159                 memcpy(cl->pending_msg->data, &cl->hdrbuf.data, sizeof(cl->hdrbuf.data));
 160         }
 161
 162         ub = cl->pending_msg;
 163         if (ub) {
 164                 int offset = cl->pending_msg_offset - sizeof(ub->hdr);
 165                 int len = blob_raw_len(ub->data) - offset;
 166                 int bytes = 0;
 167
 168                 if (len > 0) {
 169                         bytes = read(sock->fd, (char *) ub->data + offset, len);
 170                         if (bytes <= 0)
 171                                 goto out;
 172                 }
 173
 174                 if (bytes < len) {
 175                         cl->pending_msg_offset += bytes;
 176                         goto out;
 177                 }
 178
 179                 /* accept message */
 180                 ub->fd = cl->pending_msg_fd;
 181                 cl->pending_msg_fd = -1;
 182                 cl->pending_msg_offset = 0;
 183                 cl->pending_msg = NULL;
 184                 ubusd_monitor_message(cl, ub, false);
 185                 ubusd_proto_receive_message(cl, ub);
 186                 goto retry;
 187         }
 188
 189 out:
 190         if (!sock->eof || !list_empty(&cl->tx_queue))
 191                 return;
 192
 193 disconnect:
 194         handle_client_disconnect(cl);
 195 }
 196
 197 static bool get_next_connection(int fd)
 198 {
 199         struct ubus_client *cl;
 200         int client_fd;
 201
 202         client_fd = accept(fd, NULL, 0);
 203         if (client_fd < 0) {
 204                 switch (errno) {
 205                 case ECONNABORTED:
 206                 case EINTR:
 207                         return true;
 208                 default:
 209                         return false;
 210                 }
 211         }
 212
 213         cl = ubusd_proto_new_client(client_fd, client_cb);
 214         if (cl)
 215                 uloop_fd_add(&cl->sock, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 216         else
 217                 close(client_fd);
 218
 219         return true;
 220 }
 221
 222 static void server_cb(struct uloop_fd *fd, unsigned int events)
 223 {
 224         bool next;
 225
 226         do {
 227                 next = get_next_connection(fd->fd);
 228         } while (next);
 229 }
 230
 231 static struct uloop_fd server_fd = {
 232         .cb = server_cb,
 233 };
 234
 235 static int usage(const char *progname)
 236 {
 237         fprintf(stderr, "Usage: %s [<options>]\n"
 238                 "Options: \n"
 239                 "  -A <path>:           Set the path to ACL files\n"
 240                 "  -s <socket>:         Set the unix domain socket to listen on\n"
 241                 "\n", progname);
 242         return 1;
 243 }
 244
 245 static void sighup_handler(int sig)
 246 {
 247         ubusd_acl_load();
 248 }
 249
 250 static void mkdir_sockdir()
 251 {
 252         char *ubus_sock_dir, *tmp;
 253
 254         ubus_sock_dir = strdup(UBUS_UNIX_SOCKET);
 255         tmp = strrchr(ubus_sock_dir, '/');
 256         if (tmp) {
 257                 *tmp = '\0';
 258                 mkdir(ubus_sock_dir, 0755);
 259         }
 260         free(ubus_sock_dir);
 261 }
 262
 263 #include <libubox/ulog.h>
 264
 265 int main(int argc, char **argv)
 266 {
 267         const char *ubus_socket = UBUS_UNIX_SOCKET;
 268         int ret = 0;
 269         int ch;
 270
 271         signal(SIGPIPE, SIG_IGN);
 272         signal(SIGHUP, sighup_handler);
 273
 274         ulog_open(ULOG_KMSG | ULOG_SYSLOG, LOG_DAEMON, "ubusd");
 275         openlog("ubusd", LOG_PID, LOG_DAEMON);
 276         uloop_init();
 277
 278         while ((ch = getopt(argc, argv, "A:s:")) != -1) {
 279                 switch (ch) {
 280                 case 's':
 281                         ubus_socket = optarg;
 282                         break;
 283                 case 'A':
 284                         ubusd_acl_dir = optarg;
 285                         break;
 286                 default:
 287                         return usage(argv[0]);
 288                 }
 289         }
 290
 291         mkdir_sockdir();
 292         unlink(ubus_socket);
 293         umask(0111);
 294         server_fd.fd = usock(USOCK_UNIX | USOCK_SERVER | USOCK_NONBLOCK, ubus_socket, NULL);
 295         if (server_fd.fd < 0) {
 296                 perror("usock");
 297                 ret = -1;
 298                 goto out;
 299         }
 300         uloop_fd_add(&server_fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 301         ubusd_acl_load();
 302
 303         uloop_run();
 304         unlink(ubus_socket);
 305
 306 out:
 307         uloop_done();
 308         return ret;
 309 }