1 /* 2 * dhcpcd - DHCP client daemon 3 * Copyright (c) 2006-2009 Roy Marples <roy (at) marples.name> 4 * All rights reserved 5 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <linux/socket.h> 29 #include <sys/stat.h> 30 #include <sys/un.h> 31 32 #include <errno.h> 33 #include <stdio.h> 34 #include <stdlib.h> 35 #include <string.h> 36 #include <time.h> 37 #include <unistd.h> 38 39 #include "config.h" 40 #include "common.h" 41 #include "dhcpcd.h" 42 #include "control.h" 43 #include "eloop.h" 44 45 static int fd = -1; 46 static char buffer[1024]; 47 static char *argvp[255]; 48 49 struct sockaddr_un sun; 50 struct fd_list *fds = NULL; 51 52 static void 53 remove_control_data(void *arg) 54 { 55 struct fd_list *l, *last = NULL; 56 57 for (l = fds; l != NULL; l = l->next) { 58 if (l == arg) { 59 close(l->fd); 60 delete_event(l->fd); 61 if (last == NULL) 62 fds = l->next; 63 else 64 last->next = l->next; 65 free(l); 66 break; 67 } 68 last = l; 69 } 70 } 71 72 static void 73 handle_control_data(void *arg) 74 { 75 struct fd_list *l = arg; 76 ssize_t bytes; 77 int argc; 78 char *e, *p; 79 char **ap; 80 81 bytes = read(l->fd, buffer, sizeof(buffer) - 1); 82 if (bytes == -1 || bytes == 0) { 83 remove_control_data(l); 84 return; 85 } 86 buffer[bytes] = '\0'; 87 p = buffer; 88 e = buffer + bytes; 89 argc = 0; 90 ap = argvp; 91 while (p < e && (size_t)argc < sizeof(argvp)) { 92 argc++; 93 *ap++ = p; 94 p += strlen(p) + 1; 95 } 96 handle_args(l, argc, argvp); 97 } 98 99 /* ARGSUSED */ 100 static void 101 handle_control(_unused void *arg) 102 { 103 struct sockaddr_un run; 104 socklen_t len; 105 struct fd_list *l; 106 int f; 107 108 len = sizeof(run); 109 if ((f = accept(fd, (struct sockaddr *)&run, &len)) == -1) 110 return; 111 l = xmalloc(sizeof(*l)); 112 l->fd = f; 113 l->listener = 0; 114 l->next = fds; 115 fds = l; 116 add_event(l->fd, handle_control_data, l); 117 } 118 119 static int 120 make_sock(void) 121 { 122 if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) 123 return -1; 124 memset(&sun, 0, sizeof(sun)); 125 sun.sun_family = AF_UNIX; 126 strlcpy(sun.sun_path, CONTROLSOCKET, sizeof(sun.sun_path)); 127 return sizeof(sun.sun_family) + strlen(sun.sun_path) + 1; 128 } 129 130 int 131 start_control(void) 132 { 133 int len; 134 135 if ((len = make_sock()) == -1) 136 return -1; 137 unlink(CONTROLSOCKET); 138 if (bind(fd, (struct sockaddr *)&sun, len) == -1 || 139 chmod(CONTROLSOCKET, 140 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP) == -1 || 141 set_cloexec(fd) == -1 || 142 set_nonblock(fd) == -1 || 143 listen(fd, sizeof(fds)) == -1) 144 { 145 close(fd); 146 return -1; 147 } 148 add_event(fd, handle_control, NULL); 149 return fd; 150 } 151 152 int 153 stop_control(void) 154 { 155 int retval = 0; 156 struct fd_list *l, *ll; 157 158 delete_event(fd); 159 if (shutdown(fd, SHUT_RDWR) == -1) 160 retval = 1; 161 fd = -1; 162 if (unlink(CONTROLSOCKET) == -1) 163 retval = -1; 164 165 l = fds; 166 while (l != NULL) { 167 ll = l->next; 168 delete_event(l->fd); 169 shutdown(l->fd, SHUT_RDWR); 170 free(l); 171 l = ll; 172 } 173 174 return retval; 175 } 176 177 int 178 open_control(void) 179 { 180 int len; 181 182 if ((len = make_sock()) == -1) 183 return -1; 184 return connect(fd, (struct sockaddr *)&sun, len); 185 } 186 187 int 188 send_control(int argc, char * const *argv) 189 { 190 char *p = buffer; 191 int i; 192 size_t len; 193 194 if (argc > 255) { 195 errno = ENOBUFS; 196 return -1; 197 } 198 for (i = 0; i < argc; i++) { 199 len = strlen(argv[i]) + 1; 200 if ((p - buffer) + len > sizeof(buffer)) { 201 errno = ENOBUFS; 202 return -1; 203 } 204 memcpy(p, argv[i], len); 205 p += len; 206 } 207 return write(fd, buffer, p - buffer); 208 } 209
