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 #ifdef FreeBSD
  10 #include <sys/param.h>
  11 #endif
  12 #include <syslog.h>
  13
  14 #include <libubox/usock.h>
  15
  16 #include "ubusd.h"
  17
  18 static void handle_client_disconnect(struct ubus_client *cl)
  19 {
  20         struct ubus_msg_buf_list *ubl, *ubl2;
  21         list_for_each_entry_safe(ubl, ubl2, &cl->tx_queue, list)
  22                 ubus_msg_list_free(ubl);
  23
  24         ubusd_monitor_disconnect(cl);
  25         ubusd_proto_free_client(cl);
  26         if (cl->pending_msg_fd >= 0)
  27                 close(cl->pending_msg_fd);
  28         uloop_fd_delete(&cl->sock);
  29         close(cl->sock.fd);
  30         free(cl);
  31 }
  32
  33 static void client_cb(struct uloop_fd *sock, unsigned int events)
  34 {
  35         struct ubus_client *cl = container_of(sock, struct ubus_client, sock);
  36         uint8_t fd_buf[CMSG_SPACE(sizeof(int))] = { 0 };
  37         struct msghdr msghdr = { 0 };
  38         struct ubus_msg_buf *ub;
  39         struct ubus_msg_buf_list *ubl, *ubl2;
  40         static struct iovec iov;
  41         struct cmsghdr *cmsg;
  42         int *pfd;
  43
  44         msghdr.msg_iov = &iov,
  45         msghdr.msg_iovlen = 1,
  46         msghdr.msg_control = fd_buf;
  47         msghdr.msg_controllen = sizeof(fd_buf);
  48
  49         cmsg = CMSG_FIRSTHDR(&msghdr);
  50         cmsg->cmsg_type = SCM_RIGHTS;
  51         cmsg->cmsg_level = SOL_SOCKET;
  52         cmsg->cmsg_len = CMSG_LEN(sizeof(int));
  53
  54         pfd = (int *) CMSG_DATA(cmsg);
  55         msghdr.msg_controllen = cmsg->cmsg_len;
  56
  57         /* first try to tx more pending data */
  58         list_for_each_entry_safe(ubl, ubl2, &cl->tx_queue, list) {
  59                 ssize_t written;
  60
  61                 ub = ubl->msg;
  62                 written = ubus_msg_writev(sock->fd, ub, cl->txq_ofs);
  63                 if (written < 0) {
  64                         switch(errno) {
  65                         case EINTR:
  66                         case EAGAIN:
  67                                 break;
  68                         default:
  69                                 goto disconnect;
  70                         }
  71                         break;
  72                 }
  73
  74                 cl->txq_ofs += written;
  75                 cl->txq_len -= written;
  76                 if (cl->txq_ofs < ub->len + sizeof(ub->hdr))
  77                         break;
  78
  79                 ubus_msg_list_free(ubl);
  80         }
  81
  82         /* prevent further ULOOP_WRITE events if we don't have data
  83          * to send anymore */
  84         if (list_empty(&cl->tx_queue) && (events & ULOOP_WRITE))
  85                 uloop_fd_add(sock, ULOOP_READ | ULOOP_EDGE_TRIGGER);
  86
  87 retry:
  88         if (!sock->eof && cl->pending_msg_offset < (int) sizeof(cl->hdrbuf)) {
  89                 int offset = cl->pending_msg_offset;
  90                 int bytes;
  91
  92                 *pfd = -1;
  93
  94                 iov.iov_base = ((char *) &cl->hdrbuf) + offset;
  95                 iov.iov_len = sizeof(cl->hdrbuf) - offset;
  96
  97                 if (cl->pending_msg_fd < 0) {
  98                         msghdr.msg_control = fd_buf;
  99                         msghdr.msg_controllen = cmsg->cmsg_len;
 100                 } else {
 101                         msghdr.msg_control = NULL;
 102                         msghdr.msg_controllen = 0;
 103                 }
 104
 105                 bytes = recvmsg(sock->fd, &msghdr, 0);
 106                 if (bytes < 0)
 107                         goto out;
 108
 109                 if (*pfd >= 0)
 110                         cl->pending_msg_fd = *pfd;
 111
 112                 cl->pending_msg_offset += bytes;
 113                 if (cl->pending_msg_offset < (int) sizeof(cl->hdrbuf))
 114                         goto out;
 115
 116                 if (blob_pad_len(&cl->hdrbuf.data) > UBUS_MAX_MSGLEN)
 117                         goto disconnect;
 118
 119                 cl->pending_msg = ubus_msg_new(NULL, blob_raw_len(&cl->hdrbuf.data), false);
 120                 if (!cl->pending_msg)
 121                         goto disconnect;
 122
 123                 cl->hdrbuf.hdr.seq = be16_to_cpu(cl->hdrbuf.hdr.seq);
 124                 cl->hdrbuf.hdr.peer = be32_to_cpu(cl->hdrbuf.hdr.peer);
 125
 126                 memcpy(&cl->pending_msg->hdr, &cl->hdrbuf.hdr, sizeof(cl->hdrbuf.hdr));
 127                 memcpy(cl->pending_msg->data, &cl->hdrbuf.data, sizeof(cl->hdrbuf.data));
 128         }
 129
 130         ub = cl->pending_msg;
 131         if (ub) {
 132                 int offset = cl->pending_msg_offset - sizeof(ub->hdr);
 133                 int len = blob_raw_len(ub->data) - offset;
 134                 int bytes = 0;
 135
 136                 if (len > 0) {
 137                         bytes = read(sock->fd, (char *) ub->data + offset, len);
 138                         if (bytes <= 0)
 139                                 goto out;
 140                 }
 141
 142                 if (bytes < len) {
 143                         cl->pending_msg_offset += bytes;
 144                         goto out;
 145                 }
 146
 147                 /* accept message */
 148                 ub->fd = cl->pending_msg_fd;
 149                 cl->pending_msg_fd = -1;
 150                 cl->pending_msg_offset = 0;
 151                 cl->pending_msg = NULL;
 152                 ubusd_monitor_message(cl, ub, false);
 153                 ubusd_proto_receive_message(cl, ub);
 154                 goto retry;
 155         }
 156
 157 out:
 158         if (!sock->eof || !list_empty(&cl->tx_queue))
 159                 return;
 160
 161 disconnect:
 162         handle_client_disconnect(cl);
 163 }
 164
 165 static bool get_next_connection(int fd)
 166 {
 167         struct ubus_client *cl;
 168         int client_fd;
 169
 170         client_fd = accept(fd, NULL, 0);
 171         if (client_fd < 0) {
 172                 switch (errno) {
 173                 case ECONNABORTED:
 174                 case EINTR:
 175                         return true;
 176                 default:
 177                         return false;
 178                 }
 179         }
 180
 181         cl = ubusd_proto_new_client(client_fd, client_cb);
 182         if (cl)
 183                 uloop_fd_add(&cl->sock, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 184         else
 185                 close(client_fd);
 186
 187         return true;
 188 }
 189
 190 static void server_cb(struct uloop_fd *fd, unsigned int events)
 191 {
 192         bool next;
 193
 194         do {
 195                 next = get_next_connection(fd->fd);
 196         } while (next);
 197 }
 198
 199 static struct uloop_fd server_fd = {
 200         .cb = server_cb,
 201 };
 202
 203 static int usage(const char *progname)
 204 {
 205         fprintf(stderr, "Usage: %s [<options>]\n"
 206                 "Options: \n"
 207                 "  -A <path>:           Set the path to ACL files\n"
 208                 "  -s <socket>:         Set the unix domain socket to listen on\n"
 209                 "\n", progname);
 210         return 1;
 211 }
 212
 213 static void sighup_handler(int sig)
 214 {
 215         ubusd_acl_load();
 216 }
 217
 218 int main(int argc, char **argv)
 219 {
 220         const char *ubus_socket = UBUS_UNIX_SOCKET;
 221         int ret = 0;
 222         int ch;
 223
 224         signal(SIGPIPE, SIG_IGN);
 225         signal(SIGHUP, sighup_handler);
 226
 227         openlog("ubusd", LOG_PID, LOG_DAEMON);
 228         uloop_init();
 229
 230         while ((ch = getopt(argc, argv, "A:s:")) != -1) {
 231                 switch (ch) {
 232                 case 's':
 233                         ubus_socket = optarg;
 234                         break;
 235                 case 'A':
 236                         ubusd_acl_dir = optarg;
 237                         break;
 238                 default:
 239                         return usage(argv[0]);
 240                 }
 241         }
 242
 243         unlink(ubus_socket);
 244         umask(0111);
 245         server_fd.fd = usock(USOCK_UNIX | USOCK_SERVER | USOCK_NONBLOCK, ubus_socket, NULL);
 246         if (server_fd.fd < 0) {
 247                 perror("usock");
 248                 ret = -1;
 249                 goto out;
 250         }
 251         uloop_fd_add(&server_fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 252         ubusd_acl_load();
 253
 254         uloop_run();
 255         unlink(ubus_socket);
 256
 257 out:
 258         uloop_done();
 259         return ret;
 260 }