wmget/iq.c

   1 /*
   2     wmget - A background download manager as a Window Maker dock app
   3     Copyright (c) 2001-2003 Aaron Trickey <aaron@amtrickey.net>
   4
   5     Permission is hereby granted, free of charge, to any person
   6     obtaining a copy of this software and associated documentation files
   7     (the "Software"), to deal in the Software without restriction,
   8     including without limitation the rights to use, copy, modify, merge,
   9     publish, distribute, sublicense, and/or sell copies of the Software,
  10     and to permit persons to whom the Software is furnished to do so,
  11     subject to the following conditions:
  12
  13     The above copyright notice and this permission notice shall be
  14     included in all copies or substantial portions of the Software.
  15
  16     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  17     EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  18     MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  19     NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  20     CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  21     TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  22     SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23
  24     ********************************************************************
  25     iq.c - Core functions implementing the server's Unix-domain socket
  26
  27     To submit jobs to the server's input queue, you connect to a Unix-
  28     domain socket it opens.  These functions are responsible for
  29     setting up, connecting to, and accepting connections from that
  30     socket, and are used by server.c and request.c.
  31 */
  32
  33 #include <stdio.h>
  34 #include <string.h>
  35 #include <stdlib.h>
  36 #include <errno.h>
  37 #include <unistd.h>
  38 #include <fcntl.h>
  39 #include <sys/types.h>
  40 #include <sys/socket.h>
  41 #include <sys/un.h>
  42 #include <sys/poll.h>
  43 #include <sys/stat.h>
  44
  45 #include "wmget.h"
  46
  47
  48 /* iqsun == the Unix-domain socket address, aka the pathname, of our
  49  * socket.  iqsun_len == the number of bytes in iqsun incl. the header
  50  * and the pathname string, excluding the unused bytes after the
  51  * string's terminator.
  52  */
  53 static struct sockaddr_un iqsun;
  54 static int iqsun_len = 0;       /* 0 => not yet initialized */
  55 const char *iqname = ".wmget.iq";
  56
  57 int init_paths (void)
  58 {
  59     return 0;
  60 }
  61
  62 static int iq_init_address (void)
  63 {
  64     const char *homedir = home_directory ();
  65
  66     if (iqsun_len)      /* already initialized */
  67         return 0;
  68
  69     /* Our pathname length is constrained by sizeof(sockaddr_un), and
  70      * must be able to fit the homedir, the /, the iqname, and the \0.
  71      */
  72     if (strlen (homedir) > sizeof iqsun.sun_path - 2 - sizeof iqname) {
  73         error ("Home directory path is too long, can't construct "
  74                "socket name");
  75         return 1;
  76     }
  77
  78     sprintf (iqsun.sun_path, "%s/%s", homedir, iqname);
  79
  80     debug ("IQ = '%s'", iqsun.sun_path);
  81
  82     iqsun.sun_family = AF_UNIX;
  83
  84     iqsun_len = sizeof iqsun - sizeof iqsun.sun_path
  85                 + strlen (iqsun.sun_path) + 1;
  86
  87     return 0;
  88 }
  89
  90
  91 FILE *iq_client_connect (void)
  92 {
  93     int fd;
  94     FILE *fp;
  95
  96     if (iq_init_address ())
  97         return 0;
  98
  99     if ((fd = socket (AF_UNIX, SOCK_STREAM, 0)) < 0) {
 100         error_sys ("Could not create Unix-domain socket to talk to server");
 101         return 0;
 102     }
 103
 104     if (connect (fd, (struct sockaddr *)&iqsun, iqsun_len) < 0) {
 105         error_sys ("Could not connect to the server");
 106         close (fd);
 107         return 0;
 108     }
 109
 110     if (!(fp = fdopen (fd, "r+"))) {
 111         /* this should never fail for any reparable reason */
 112         error_sys ("fdopen");
 113         close (fd);
 114         return 0;
 115     }
 116
 117     return fp;
 118 }
 119
 120 /* Server listener socket */
 121 static int iq_listen_fd;
 122
 123
 124 /** was going to use this in atexit(), but the problem is that we fork,
 125  * and those children inherit the atexits, and well ...
 126 static void iq_server_cleanup (void)
 127 {
 128     close (iq_listen_fd);
 129     unlink (iqsun.sun_path);
 130 }
 131 */
 132
 133
 134 int iq_server_init (void)
 135 {
 136     int fd, test_fd;
 137
 138     if (iq_init_address ())
 139         return 1;
 140
 141
 142     if ((fd = socket (AF_UNIX, SOCK_STREAM, 0)) < 0) {
 143         error_sys ("Could not create Unix-domain socket to receive requests");
 144         return 1;
 145     }
 146
 147     /* We're going to listen on this socket and don't want accept() to
 148      * block
 149      */
 150     if (fcntl (fd, F_SETFL, (long)O_NONBLOCK) < 0) {
 151         error_sys ("fcntl");
 152         close (fd);
 153         return 1;
 154     }
 155
 156     /* Before proceeding, try to *connect* to the iq.  If this succeeds,
 157      * then uh-oh, there's another wmget running out there.
 158      */
 159     test_fd = connect (fd, (struct sockaddr *)&iqsun, iqsun_len);
 160     if (test_fd >= 0) {
 161         close (test_fd);
 162         error (
 163             "There's another wmget dock running.  You can only run "
 164             "one at a time.");
 165         return 1;
 166     }
 167
 168     /* Good.  Just in case the pathname exists, unlink it. */
 169     unlink (iqsun.sun_path);
 170
 171     if (bind (fd, (struct sockaddr *)&iqsun, iqsun_len) < 0) {
 172         error_sys ("bind");
 173         close (fd);
 174         return 1;
 175     }
 176
 177     /* Tighten up the new filename's permissions. */
 178     if (chmod (iqsun.sun_path, S_IRWXU) < 0) {
 179         error_sys ("chmod");
 180         close (fd);
 181         return 1;
 182     }
 183
 184     if (listen (fd, 5) < 0) {
 185         error_sys ("listen");
 186         close (fd);
 187         return 1;
 188     }
 189
 190     iq_listen_fd = fd;
 191
 192     return 0;
 193 }
 194
 195
 196 FILE *iq_server_accept (void)
 197 {
 198     int fd;
 199     FILE *fp;
 200     struct sockaddr_un sun;
 201     int sun_len = sizeof sun;
 202
 203     if ((fd = accept (iq_listen_fd, (struct sockaddr *)&sun,
 204                       &sun_len)) < 0) {
 205         if (errno == EAGAIN) {
 206             /* Simply no connections waiting. */
 207             return 0;
 208         }
 209
 210         error_sys ("accept");
 211         return 0;
 212     }
 213
 214     debug ("got a connection...");
 215
 216     if (!(fp = fdopen (fd, "r+"))) {
 217         error_sys ("fdopen");
 218         close (fd);
 219         return 0;
 220     }
 221
 222     return fp;
 223 }
 224
 225
 226 int iq_get_listen_fd (void)
 227 {
 228     return iq_listen_fd;
 229 }
 230
 231
 232
 233