git.demorecorder.com Git - free-sw/xcb/libxcb/blob - src/xcb_conn.c

   1 /* Copyright (C) 2001-2004 Bart Massey and Jamey Sharp.
   2  *
   3  * Permission is hereby granted, free of charge, to any person obtaining a
   4  * copy of this software and associated documentation files (the "Software"),
   5  * to deal in the Software without restriction, including without limitation
   6  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   7  * and/or sell copies of the Software, and to permit persons to whom the
   8  * Software is furnished to do so, subject to the following conditions:
   9  *
  10  * The above copyright notice and this permission notice shall be included in
  11  * all copies or substantial portions of the Software.
  12  *
  13  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  14  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  15  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  16  * AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  17  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  18  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  19  *
  20  * Except as contained in this notice, the names of the authors or their
  21  * institutions shall not be used in advertising or otherwise to promote the
  22  * sale, use or other dealings in this Software without prior written
  23  * authorization from the authors.
  24  */
  25
  26 /* Connection management: the core of XCB. */
  27
  28 #include <assert.h>
  29 #include <string.h>
  30 #include <stdio.h>
  31 #include <unistd.h>
  32 #include <stdlib.h>
  33 #include <netinet/in.h>
  34 #include <sys/select.h>
  35 #include <sys/fcntl.h>
  36
  37 #include "xcb.h"
  38 #include "xcbint.h"
  39
  40 static int set_fd_flags(const int fd)
  41 {
  42     long flags = fcntl(fd, F_GETFL, 0);
  43     if(flags == -1)
  44         return 0;
  45     flags |= O_NONBLOCK;
  46     if(fcntl(fd, F_SETFL, flags) == -1)
  47         return 0;
  48     if(fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
  49         return 0;
  50     return 1;
  51 }
  52
  53 static int write_setup(XCBConnection *c, XCBAuthInfo *auth_info)
  54 {
  55     static const char pad[3];
  56     XCBConnSetupReq out;
  57     struct iovec parts[6];
  58     int count = 0;
  59     int endian = 0x01020304;
  60     int ret;
  61
  62     memset(&out, 0, sizeof(out));
  63
  64     /* B = 0x42 = MSB first, l = 0x6c = LSB first */
  65     if(htonl(endian) == endian)
  66         out.byte_order = 0x42;
  67     else
  68         out.byte_order = 0x6c;
  69     out.protocol_major_version = X_PROTOCOL;
  70     out.protocol_minor_version = X_PROTOCOL_REVISION;
  71     out.authorization_protocol_name_len = 0;
  72     out.authorization_protocol_data_len = 0;
  73     parts[count].iov_len = sizeof(XCBConnSetupReq);
  74     parts[count++].iov_base = &out;
  75     parts[count].iov_len = XCB_PAD(sizeof(XCBConnSetupReq));
  76     parts[count++].iov_base = (caddr_t) pad;
  77
  78     if(auth_info)
  79     {
  80         parts[count].iov_len = out.authorization_protocol_name_len = auth_info->namelen;
  81         parts[count++].iov_base = auth_info->name;
  82         parts[count].iov_len = XCB_PAD(out.authorization_protocol_name_len);
  83         parts[count++].iov_base = (caddr_t) pad;
  84         parts[count].iov_len = out.authorization_protocol_data_len = auth_info->datalen;
  85         parts[count++].iov_base = auth_info->data;
  86         parts[count].iov_len = XCB_PAD(out.authorization_protocol_data_len);
  87         parts[count++].iov_base = (caddr_t) pad;
  88     }
  89     assert(count <= sizeof(parts) / sizeof(*parts));
  90
  91     pthread_mutex_lock(&c->iolock);
  92     _xcb_out_write_block(c, parts, count);
  93     ret = _xcb_out_flush(c);
  94     pthread_mutex_unlock(&c->iolock);
  95     return ret;
  96 }
  97
  98 static int read_setup(XCBConnection *c)
  99 {
 100     /* Read the server response */
 101     c->setup = malloc(sizeof(XCBConnSetupGenericRep));
 102     if(!c->setup)
 103         return 0;
 104
 105     if(_xcb_in_read_block(c, c->setup, sizeof(XCBConnSetupGenericRep)) != sizeof(XCBConnSetupGenericRep))
 106         return 0;
 107
 108     {
 109         void *tmp = realloc(c->setup, c->setup->length * 4 + sizeof(XCBConnSetupGenericRep));
 110         if(!tmp)
 111             return 0;
 112         c->setup = tmp;
 113     }
 114
 115     if(_xcb_in_read_block(c, (char *) c->setup + sizeof(XCBConnSetupGenericRep), c->setup->length * 4) <= 0)
 116         return 0;
 117
 118     /* 0 = failed, 2 = authenticate, 1 = success */
 119     switch(c->setup->status)
 120     {
 121     case 0: /* failed */
 122         {
 123             XCBConnSetupFailedRep *setup = (XCBConnSetupFailedRep *) c->setup;
 124             write(STDERR_FILENO, XCBConnSetupFailedRepReason(setup), XCBConnSetupFailedRepReasonLength(setup));
 125             return 0;
 126         }
 127
 128     case 2: /* authenticate */
 129         {
 130             XCBConnSetupAuthenticateRep *setup = (XCBConnSetupAuthenticateRep *) c->setup;
 131             write(STDERR_FILENO, XCBConnSetupAuthenticateRepReason(setup), XCBConnSetupAuthenticateRepReasonLength(setup));
 132             return 0;
 133         }
 134     }
 135
 136     return 1;
 137 }
 138
 139 /* Public interface */
 140
 141 XCBConnSetupSuccessRep *XCBGetSetup(XCBConnection *c)
 142 {
 143     /* doesn't need locking because it's never written to. */
 144     return c->setup;
 145 }
 146
 147 int XCBGetFileDescriptor(XCBConnection *c)
 148 {
 149     /* doesn't need locking because it's never written to. */
 150     return c->fd;
 151 }
 152
 153 XCBConnection *XCBConnectToFD(int fd, XCBAuthInfo *auth_info)
 154 {
 155     XCBConnection* c;
 156
 157     c = calloc(1, sizeof(XCBConnection));
 158     if(!c)
 159         return 0;
 160
 161     c->fd = fd;
 162
 163     if(!(
 164         set_fd_flags(fd) &&
 165         pthread_mutex_init(&c->iolock, 0) == 0 &&
 166         _xcb_in_init(&c->in) &&
 167         _xcb_out_init(&c->out) &&
 168         write_setup(c, auth_info) &&
 169         read_setup(c) &&
 170         _xcb_ext_init(c) &&
 171         _xcb_xid_init(c)
 172         ))
 173     {
 174         XCBDisconnect(c);
 175         return 0;
 176     }
 177
 178     return c;
 179 }
 180
 181 void XCBDisconnect(XCBConnection *c)
 182 {
 183     if(!c)
 184         return;
 185
 186     free(c->setup);
 187     close(c->fd);
 188
 189     pthread_mutex_destroy(&c->iolock);
 190     _xcb_in_destroy(&c->in);
 191     _xcb_out_destroy(&c->out);
 192
 193     _xcb_ext_destroy(c);
 194     _xcb_xid_destroy(c);
 195
 196     free(c);
 197 }
 198
 199 /* Private interface */
 200
 201 int _xcb_conn_wait(XCBConnection *c, const int should_write, pthread_cond_t *cond)
 202 {
 203     int ret;
 204     fd_set rfds, wfds;
 205
 206     /* If the thing I should be doing is already being done, wait for it. */
 207     if(should_write ? c->out.writing : c->in.reading)
 208     {
 209         pthread_cond_wait(cond, &c->iolock);
 210         return 1;
 211     }
 212
 213     FD_ZERO(&rfds);
 214     FD_SET(c->fd, &rfds);
 215     ++c->in.reading;
 216
 217     FD_ZERO(&wfds);
 218     if(should_write)
 219     {
 220         FD_SET(c->fd, &wfds);
 221         ++c->out.writing;
 222     }
 223
 224     pthread_mutex_unlock(&c->iolock);
 225     ret = select(c->fd + 1, &rfds, &wfds, 0, 0) > 0;
 226     pthread_mutex_lock(&c->iolock);
 227
 228     if(ret)
 229     {
 230         if(FD_ISSET(c->fd, &rfds))
 231             ret = ret && _xcb_in_read(c);
 232
 233         if(FD_ISSET(c->fd, &wfds))
 234             ret = ret && _xcb_out_write(c);
 235     }
 236
 237     if(should_write)
 238         --c->out.writing;
 239     --c->in.reading;
 240
 241     return ret;
 242 }