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