| 1 | /* Copyright (C) 2018 Thomas Balzer */ |
| 2 | |
| 3 | /* This file is part of tomd. */ |
| 4 | |
| 5 | /* tomd is free software: you can redistribute it and/or modify */ |
| 6 | /* it under the terms of the GNU General Public License as published by */ |
| 7 | /* the Free Software Foundation, either version 3 of the License, or */ |
| 8 | /* (at your option) any later version. */ |
| 9 | |
| 10 | /* tomd is distributed in the hope that it will be useful, */ |
| 11 | /* but WITHOUT ANY WARRANTY; without even the implied warranty of */ |
| 12 | /* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */ |
| 13 | /* GNU General Public License for more details. */ |
| 14 | |
| 15 | /* You should have received a copy of the GNU General Public License */ |
| 16 | /* along with tomd. If not, see <http://www.gnu.org/licenses/>. */ |
| 17 | |
| 18 | #include <fcntl.h> |
| 19 | #include <stddef.h> |
| 20 | #include <stdio.h> |
| 21 | #include <errno.h> |
| 22 | #include <stdlib.h> |
| 23 | #include <unistd.h> |
| 24 | #include <string.h> |
| 25 | #include <sys/un.h> |
| 26 | #include <sys/stat.h> |
| 27 | #include <sys/socket.h> |
| 28 | #include <sys/wait.h> |
| 29 | |
| 30 | #include "../include/macros.h" |
| 31 | #include "../include/manifest.h" |
| 32 | #include "../include/job.h" |
| 33 | |
| 34 | static void header(void) |
| 35 | { |
| 36 | tomd_p("Tom's Daemon, Copyright (C) 2018 Thomas Balzer"); |
| 37 | tomd_p("GPL v3 or later license."); |
| 38 | } |
| 39 | |
| 40 | static int sfd; |
| 41 | static char socket_dirname[100]; |
| 42 | static char socket_filename[100]; |
| 43 | |
| 44 | static void gen_socket_filename(void) |
| 45 | { |
| 46 | uid_t this_user_id = |
| 47 | getuid(); |
| 48 | sprintf(socket_dirname, |
| 49 | "/run/user/%d/tomd", |
| 50 | this_user_id); |
| 51 | sprintf(socket_filename, |
| 52 | "/run/user/%d/tomd/socket", |
| 53 | this_user_id); |
| 54 | |
| 55 | tomd_p("making dir '%s'", socket_dirname); |
| 56 | /* lazy way */ |
| 57 | /* char buf[100]; */ |
| 58 | /* sprintf(buf, "mkdir -p %s", socket_dirname); */ |
| 59 | /* system(buf); */ |
| 60 | |
| 61 | if(mkdir(socket_dirname, S_IRWXU) != 0){ |
| 62 | if(errno != EEXIST){ |
| 63 | tomd_panic("socket mkdir"); |
| 64 | }else{ |
| 65 | tomd_p("socket dir exists."); |
| 66 | } |
| 67 | } |
| 68 | |
| 69 | tomd_p("removing file '%s'", socket_filename); |
| 70 | if(unlink(socket_filename) != 0){ |
| 71 | if(errno == ENOENT){ |
| 72 | tomd_p("socket file doesn't exist"); |
| 73 | }else{ |
| 74 | tomd_panic("socket unlink"); |
| 75 | } |
| 76 | } |
| 77 | } |
| 78 | |
| 79 | static void socket_init(void) |
| 80 | { |
| 81 | gen_socket_filename(); |
| 82 | |
| 83 | /* listen on socket, respond to requests. */ |
| 84 | /* perform all registered 'tick' operations */ |
| 85 | sfd = |
| 86 | socket(PF_LOCAL, /* namespace - local unix socket */ |
| 87 | SOCK_STREAM, /* style */ |
| 88 | 0); /* protocol */ |
| 89 | |
| 90 | if(sfd < 0){ |
| 91 | tomd_panic("socket"); |
| 92 | } |
| 93 | |
| 94 | if(fcntl(sfd, F_SETFL, O_NONBLOCK) == -1){ |
| 95 | tomd_panic("fnctl"); |
| 96 | } |
| 97 | |
| 98 | struct sockaddr_un name; |
| 99 | size_t size; |
| 100 | |
| 101 | name.sun_family = AF_LOCAL; |
| 102 | strncpy(name.sun_path, |
| 103 | socket_filename, |
| 104 | sizeof(name.sun_path)); |
| 105 | |
| 106 | size = SUN_LEN(&name); |
| 107 | tomd_p("attempting to bind to '%s'", |
| 108 | socket_filename); |
| 109 | if(bind(sfd, |
| 110 | (struct sockaddr *) &name, |
| 111 | size) < 0){ |
| 112 | tomd_panic("bind"); |
| 113 | } |
| 114 | |
| 115 | tomd_p("initialized tomd socket connections"); |
| 116 | } |
| 117 | |
| 118 | static void init(void) |
| 119 | { |
| 120 | socket_init(); |
| 121 | load_jobs(); |
| 122 | } |
| 123 | |
| 124 | #define SEND_ACK { \ |
| 125 | int size; \ |
| 126 | char ACK[4]; \ |
| 127 | ACK[0] = 'A'; \ |
| 128 | ACK[1] = 'C'; \ |
| 129 | ACK[2] = 'K'; \ |
| 130 | ACK[3] = '\0'; \ |
| 131 | if(size = write(asfd, ACK, sizeof(ACK)) != sizeof(ACK)) { \ |
| 132 | tomd_p("didn't send as much as we though (%d != %d)", \ |
| 133 | size, sizeof(ACK)); \ |
| 134 | } \ |
| 135 | } |
| 136 | |
| 137 | #define CHDIR 0 |
| 138 | #define DONT_CHDIR 1 |
| 139 | #define CLOSE_PIPES 0 |
| 140 | #define DONT_CLOSE_PIPES 1 |
| 141 | |
| 142 | static void daemonize(void) |
| 143 | { |
| 144 | /* daemon is in unistd. */ |
| 145 | /* arg1 - 0 changes dir to / */ |
| 146 | /* arg2 - 0 closes all pipes (/dev/null) */ |
| 147 | /* WARNING > THIS BEHAVIOR IS SILENT AND EASY TO MISPLACE THE |
| 148 | PROCESS */ |
| 149 | /* daemon will exit the original process. */ |
| 150 | daemon(DONT_CHDIR, DONT_CLOSE_PIPES); |
| 151 | } |
| 152 | |
| 153 | #define READ_SOCKET { \ |
| 154 | memset(buf, 0, sizeof(buf)); \ |
| 155 | int size = read(asfd, buf, 100); \ |
| 156 | buf[size] = '\0'; \ |
| 157 | } |
| 158 | |
| 159 | static int validate_sender(int asfd, char *buf) |
| 160 | { |
| 161 | READ_SOCKET; |
| 162 | if(strcmp(buf, "client:tomc") == 0){ |
| 163 | SEND_ACK; |
| 164 | return 0; |
| 165 | } |
| 166 | tomd_p("received '%s' instead of client:tomc", buf); |
| 167 | return -1; |
| 168 | } |
| 169 | |
| 170 | enum requests { KILL, STATUS, STOP, START, UNKNOWN}; |
| 171 | #define X(a, b) { a, b } |
| 172 | static struct { |
| 173 | char *str; |
| 174 | enum requests request; |
| 175 | } request_types[] = |
| 176 | { |
| 177 | X("kill", KILL), |
| 178 | X("status", STATUS), |
| 179 | X("start", START), |
| 180 | X("stop", STOP), |
| 181 | X(NULL, -1) |
| 182 | }; |
| 183 | #undef X |
| 184 | |
| 185 | static void handle_request(int asfd, char *buf) |
| 186 | { |
| 187 | READ_SOCKET; |
| 188 | enum requests request = UNKNOWN; |
| 189 | int i = 0; |
| 190 | while(1){ |
| 191 | if(request_types[i].str == NULL){ |
| 192 | break; |
| 193 | } |
| 194 | |
| 195 | tomd_p("loop [%d]: comparing '%s' to '%s'", |
| 196 | i, buf, request_types[i].str); |
| 197 | if(strcmp(buf, request_types[i].str) == 0){ |
| 198 | request = request_types[i].request; |
| 199 | break; |
| 200 | } |
| 201 | |
| 202 | i++; |
| 203 | } |
| 204 | |
| 205 | if(request == UNKNOWN){ |
| 206 | tomd_p("unknown request type!"); |
| 207 | return; |
| 208 | } |
| 209 | |
| 210 | SEND_ACK; |
| 211 | READ_SOCKET; |
| 212 | // cross reference given name against known services |
| 213 | tomd_p("looking up '%s'", buf); |
| 214 | SEND_ACK; |
| 215 | struct job *jp = lookup_job(buf); |
| 216 | #define DOUBLE_DUTY(...) { \ |
| 217 | char tmp[100]; \ |
| 218 | tomd_p(__VA_ARGS__); \ |
| 219 | sprintf(tmp, __VA_ARGS__); \ |
| 220 | int tmplen = strlen(tmp); \ |
| 221 | tomd_p("__debug__:'%s'", tmp); \ |
| 222 | write(asfd, tmp, tmplen); \ |
| 223 | } |
| 224 | if(jp == NULL){ |
| 225 | DOUBLE_DUTY("lookup of '%s' failed.\n", buf); |
| 226 | } else { |
| 227 | tomd_p("-----"); |
| 228 | DOUBLE_DUTY("found job record for '%s'\n", jp->name); |
| 229 | |
| 230 | if(request == STATUS){ |
| 231 | if(jp->pid != -1){ |
| 232 | int status = 0; |
| 233 | int n_pid = waitpid(jp->pid, &status, WNOHANG); |
| 234 | if(n_pid < 0){ |
| 235 | perror("[tomd] waitpid"); |
| 236 | }else if(n_pid == 0){ |
| 237 | DOUBLE_DUTY("waitpid == 0, check manual\n"); |
| 238 | }else{ |
| 239 | DOUBLE_DUTY("running: %s\n", |
| 240 | !WIFEXITED(status) ? "yes" |
| 241 | : "no"); |
| 242 | |
| 243 | if(WIFEXITED(status)){ |
| 244 | DOUBLE_DUTY(" status: %d\n", WEXITSTATUS(status)); |
| 245 | jp->pid = -1; |
| 246 | jp->last_status = status; |
| 247 | } |
| 248 | } |
| 249 | }else{ |
| 250 | DOUBLE_DUTY("running: no\n"); |
| 251 | DOUBLE_DUTY(" status: %d\n", jp->last_status); |
| 252 | } |
| 253 | |
| 254 | if(jp->pid != -1){ |
| 255 | DOUBLE_DUTY(" pid: %d\n", jp->pid); |
| 256 | } |
| 257 | }else{ |
| 258 | DOUBLE_DUTY("don't know how to handle that request.\n"); |
| 259 | } |
| 260 | } |
| 261 | tomd_p("-----"); |
| 262 | tomd_p("sending ack."); |
| 263 | SEND_ACK; |
| 264 | tomd_p("ack is sent."); |
| 265 | get_ack: |
| 266 | READ_SOCKET; |
| 267 | if(strcmp(buf, "ACK") != 0) |
| 268 | goto get_ack; |
| 269 | tomd_p("ack was ack'd."); |
| 270 | } |
| 271 | |
| 272 | static void handle_connection(int asfd) |
| 273 | { |
| 274 | char buf[100] = {}; |
| 275 | |
| 276 | if(validate_sender(asfd, buf) != 0){ |
| 277 | tomd_p("invalid sender."); |
| 278 | return; |
| 279 | } |
| 280 | |
| 281 | tomd_p("validated client"); |
| 282 | handle_request(asfd, buf); |
| 283 | |
| 284 | shutdown(asfd, SHUT_WR); |
| 285 | close(asfd); |
| 286 | } |
| 287 | |
| 288 | static void run(void) |
| 289 | { |
| 290 | /* loop: */ |
| 291 | /* 1 listen */ |
| 292 | /* 2 accept/select */ |
| 293 | /* 3 handle dgram */ |
| 294 | int listen_bool = |
| 295 | listen(sfd, |
| 296 | 10); /* max connection limit is 10 for arbitrary reasons */ |
| 297 | if(listen_bool == -1){ |
| 298 | tomd_panic("listen"); |
| 299 | } |
| 300 | |
| 301 | for(;;){ |
| 302 | struct sockaddr addr; |
| 303 | /* sometimes gives EINVAL if not initialized. */ |
| 304 | socklen_t size = sizeof(addr); |
| 305 | errno = 0; |
| 306 | int accept_sfd = |
| 307 | accept(sfd, |
| 308 | &addr, /* requester info */ |
| 309 | &size); /* len of requester info */ |
| 310 | if(accept_sfd < 0){ |
| 311 | if(errno == EINVAL){ |
| 312 | tomd_p("EINVAL"); |
| 313 | }else if(errno == EWOULDBLOCK || errno == EAGAIN){ |
| 314 | /* no worries */ |
| 315 | }else { |
| 316 | tomd_panic("accept socket"); |
| 317 | } |
| 318 | } else { |
| 319 | handle_connection(accept_sfd); |
| 320 | } |
| 321 | |
| 322 | check_root_job(); |
| 323 | usleep(10); |
| 324 | } |
| 325 | } |
| 326 | |
| 327 | static void cleanup(void) |
| 328 | { |
| 329 | if(sfd >= 0){ |
| 330 | close(sfd); |
| 331 | } |
| 332 | } |
| 333 | |
| 334 | int main(int argc, char **argv) |
| 335 | { |
| 336 | header(); |
| 337 | init(); |
| 338 | /* daemonize(); */ |
| 339 | run_jobs(); |
| 340 | /* silent(); */ |
| 341 | run(); |
| 342 | cleanup(); |
| 343 | |
| 344 | return EXIT_SUCCESS; |
| 345 | } |