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Rev | Author | Line No. | Line |
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1140 | dev | 1 | /****************************************************************** |
1159 | dev | 2 | * rebootd. |
1140 | dev | 3 | * |
1168 | dev | 4 | * A daemon which waits on specified UDP port for special string |
1159 | dev | 5 | * (password) and reboots the computer. |
1140 | dev | 6 | * |
1171 | dev | 7 | * Run "./rebootd --help" to see options and parameters. |
1140 | dev | 8 | * |
9 | * Copyleft 2005 Anatoli Klassen |
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10 | * |
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11 | ******************************************************************/ |
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12 | |||
13 | #include <stdlib.h> |
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14 | #include <stdio.h> |
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15 | #include <string.h> |
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16 | #include <errno.h> |
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1187 | dev | 17 | #include <syslog.h> |
1140 | dev | 18 | #include <unistd.h> |
1165 | dev | 19 | #include <fcntl.h> |
1144 | dev | 20 | #include <sys/stat.h> |
1140 | dev | 21 | #include <sys/reboot.h> |
22 | |||
1187 | dev | 23 | #include "common.h" |
24 | #include "rebootd.h" |
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25 | #include "config.h" |
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26 | #include "signals.h" |
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27 | #include "network.h" |
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1144 | dev | 28 | |
1187 | dev | 29 | int daemonized = 0; /* we are already a daemon */ |
30 | volatile int reconfig_required = 0; /* we have to stop socket listening and reread config */ |
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31 | volatile int quit_required = 0; /* we have to stop socket listening and exit */ |
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1140 | dev | 32 | |
1187 | dev | 33 | void handle_command(const struct config *cfg, const char *cmd, const int cmd_len) |
1140 | dev | 34 | { |
1187 | dev | 35 | if(0 != strncmp(cmd, cfg->password, cmd_len)) return; /* wrong password */ |
1140 | dev | 36 | |
1187 | dev | 37 | if(cfg->debug_mode) { |
38 | syslog(LOG_INFO, "REBOOT, debug mode"); |
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1140 | dev | 39 | } |
1165 | dev | 40 | else { |
1187 | dev | 41 | syslog(LOG_EMERG, "REBOOT"); |
42 | sleep(5); |
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43 | if(reboot(RB_AUTOBOOT) < 0) { |
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44 | syslog(LOG_ERR, "cannot reboot, %s", strerror(errno)); |
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1164 | dev | 45 | } |
1140 | dev | 46 | } |
47 | } |
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48 | |||
1165 | dev | 49 | static int save_pid(const char *pid_file, const pid_t pid) |
50 | { |
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51 | int fd; |
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52 | FILE *file; |
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53 | |||
54 | if(!pid_file || pid_file[0] == '\0') return RESULT_OK; |
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55 | |||
56 | unlink(pid_file); |
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57 | |||
58 | fd = open(pid_file, O_WRONLY | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH); |
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59 | if(fd < 0) { |
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60 | syslog(LOG_ERR, "Can open PID file %s for write: %s\n", pid_file, strerror(errno)); |
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61 | return RESULT_ERROR; |
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62 | } |
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63 | |||
64 | file = fdopen(fd, "w"); |
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65 | if(!file) { |
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66 | syslog(LOG_ERR, "Can open PID file %s for write: %s\n", pid_file, strerror(errno)); |
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67 | return RESULT_ERROR; |
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68 | } |
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69 | |||
70 | if(fprintf(file, "%d\n", pid) < 0) { |
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71 | syslog(LOG_ERR, "Can write PID to file %s: %s\n", pid_file, strerror(errno)); |
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72 | return RESULT_ERROR; |
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73 | } |
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74 | |||
75 | if(fclose(file) != 0) { |
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76 | syslog(LOG_ERR, "Can not close PID file %s: %s\n", pid_file, strerror(errno)); |
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77 | return RESULT_UNEXPECTED; |
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78 | } |
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79 | |||
80 | return RESULT_OK; |
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81 | } |
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82 | |||
1156 | dev | 83 | static int create_child(int soc) |
1143 | dev | 84 | { |
85 | pid_t child; |
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86 | |||
87 | child = fork(); |
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88 | if(child == -1) { |
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89 | fprintf(stderr, "Cannot fork: %s\n", strerror(errno)); |
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1145 | dev | 90 | return RESULT_UNEXPECTED; /* an unexpected error */ |
1143 | dev | 91 | } |
92 | else if(child > 0) { |
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1156 | dev | 93 | if(close(soc) != 0) { |
1143 | dev | 94 | fprintf(stderr, "Cannot close socket: %s\n", strerror(errno)); |
1145 | dev | 95 | return RESULT_UNEXPECTED; /* an unexpected error */ |
1143 | dev | 96 | } |
1165 | dev | 97 | |
1145 | dev | 98 | return RESULT_EXIT; /* we are the parent */ |
1143 | dev | 99 | } |
100 | else { |
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1145 | dev | 101 | return RESULT_OK; /* we are the child */ |
1143 | dev | 102 | } |
103 | } |
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104 | |||
105 | static int close_descr(int d) |
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106 | { |
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107 | if(close(d) != 0) { |
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108 | syslog(LOG_ERR, "Cannot close descriptor %d: %s\n", d, strerror(errno)); |
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1145 | dev | 109 | return RESULT_UNEXPECTED; |
1143 | dev | 110 | } |
1145 | dev | 111 | return RESULT_OK; |
1143 | dev | 112 | } |
113 | |||
1187 | dev | 114 | static void delete_pid_file(const char *pid_file) |
1165 | dev | 115 | { |
1187 | dev | 116 | if(pid_file && pid_file[0] != '\0') { |
117 | if(unlink(pid_file) != 0) { |
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118 | syslog(LOG_ERR, "Cannot delete PID file %s: %s\n", pid_file, strerror(errno)); |
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1165 | dev | 119 | } |
120 | } |
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121 | } |
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122 | |||
1187 | dev | 123 | static void check_return(int res, const struct config *cfg) |
1169 | dev | 124 | { |
1165 | dev | 125 | if(daemonized && res != RESULT_OK) { |
1187 | dev | 126 | delete_pid_file(cfg->pid_file); |
1165 | dev | 127 | syslog(LOG_WARNING, "quit"); |
128 | } |
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129 | |||
130 | switch(res) { |
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131 | case RESULT_EXIT: exit(EXIT_OK); return; /* no error but exit */ |
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132 | case RESULT_ERROR: exit(EXIT_USER_ERROR); return; /* user error */ |
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133 | case RESULT_UNEXPECTED: exit(EXIT_UNEXPECTED); return; /* unexpected error */ |
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134 | } |
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135 | } |
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136 | |||
1156 | dev | 137 | int main(int argc, const char* argv[]) |
1140 | dev | 138 | { |
1187 | dev | 139 | int soc; |
140 | int reinit_needed; |
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141 | struct config cfg; |
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1140 | dev | 142 | |
1143 | dev | 143 | /* get config */ |
1187 | dev | 144 | check_return(read_config(&cfg, argc, argv), &cfg); |
1143 | dev | 145 | |
146 | /* try to listen the port */ |
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1187 | dev | 147 | if((soc = establish(&cfg)) < 0) { |
148 | fprintf(stderr, "Cannot listen to port %i\n", cfg.port); |
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1145 | dev | 149 | return EXIT_USER_ERROR; |
1140 | dev | 150 | } |
151 | |||
1143 | dev | 152 | /* fork and release the console */ |
1187 | dev | 153 | check_return(create_child(soc), &cfg); |
1140 | dev | 154 | |
1143 | dev | 155 | /* continue as first child */ |
156 | if(setsid() == -1) { |
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157 | fprintf(stderr, "Cannot create session: %s\n", strerror(errno)); |
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1145 | dev | 158 | return EXIT_UNEXPECTED; |
1143 | dev | 159 | } |
160 | |||
161 | /* fork the second time */ |
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1187 | dev | 162 | check_return(create_child(soc), &cfg); |
1165 | dev | 163 | |
164 | /* continue as final child */ |
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165 | if(init_signals() != RESULT_OK) return EXIT_UNEXPECTED; |
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166 | |||
167 | if(chdir("/") < 0) { |
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168 | fprintf(stderr, "Cannot chdir to /: %s\n", strerror(errno)); |
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169 | return EXIT_UNEXPECTED; |
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1143 | dev | 170 | } |
1165 | dev | 171 | umask(0); |
1187 | dev | 172 | check_return(save_pid(cfg.pid_file, getpid()), &cfg); |
1165 | dev | 173 | daemonized = 1; |
1143 | dev | 174 | |
1165 | dev | 175 | /* from now do not use console for error output */ |
1145 | dev | 176 | if(close_descr(0) != RESULT_OK) return EXIT_UNEXPECTED; |
177 | if(close_descr(1) != RESULT_OK) return EXIT_UNEXPECTED; |
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178 | if(close_descr(2) != RESULT_OK) return EXIT_UNEXPECTED; |
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1143 | dev | 179 | |
1165 | dev | 180 | for(;;) { |
1187 | dev | 181 | syslog(LOG_INFO, "listen on %d", cfg.port); |
182 | listen_socket(&cfg, soc); |
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1143 | dev | 183 | |
1169 | dev | 184 | if(quit_required) { |
185 | break; |
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186 | } |
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187 | else if(reconfig_required) { |
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188 | reconfig_required = 0; |
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1187 | dev | 189 | check_return(reread_config(&cfg, &reinit_needed), &cfg); |
1165 | dev | 190 | if(reinit_needed) { |
191 | close(soc); |
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192 | |||
1187 | dev | 193 | if((soc = establish(&cfg)) < 0) { |
194 | syslog(LOG_ERR, "Cannot listen to port %i\n", cfg.port); |
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195 | check_return(RESULT_ERROR, &cfg); |
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1165 | dev | 196 | } |
197 | } |
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198 | } |
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199 | } |
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200 | |||
1187 | dev | 201 | delete_pid_file(cfg.pid_file); |
1169 | dev | 202 | return EXIT_OK; |
1140 | dev | 203 | } |
204 |