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