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Rev | Author | Line No. | Line |
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1140 | dev | 1 | /****************************************************************** |
1145 | dev | 2 | * RebootDaemon. |
1140 | dev | 3 | * |
1145 | dev | 4 | * A daemon which waits on specified TCP port for special string |
1143 | dev | 5 | * and reboots the computer. |
1140 | dev | 6 | * |
7 | * Command line: rebootdaemon [--port PORT] [--config CONFIG_FILE] |
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8 | * Defaults are port 19 and config /etc/rebootdaemon.conf. |
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9 | * |
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10 | * Config file looks like: |
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11 | * -------------------------- |
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12 | * port=19 |
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13 | * password="some password" |
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14 | * -------------------------- |
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15 | * |
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16 | * Usage example (from any other host): |
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17 | * echo -n "some password" | nc host_to_rebot 19 |
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18 | * |
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19 | * Copyleft 2005 Anatoli Klassen |
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20 | * |
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21 | ******************************************************************/ |
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22 | |||
23 | #include <stdlib.h> |
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24 | #include <stdio.h> |
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25 | #include <string.h> |
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26 | #include <stdarg.h> |
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1144 | dev | 27 | #include <ctype.h> |
1140 | dev | 28 | #include <errno.h> |
29 | #include <signal.h> |
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30 | #include <unistd.h> |
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31 | #include <netdb.h> |
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32 | #include <syslog.h> |
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33 | #include <sys/types.h> |
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1144 | dev | 34 | #include <sys/stat.h> |
1140 | dev | 35 | #include <sys/socket.h> |
36 | #include <sys/wait.h> |
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37 | #include <sys/reboot.h> |
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38 | #include <netinet/in.h> |
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39 | #include <arpa/inet.h> |
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40 | |||
1145 | dev | 41 | /* name version number */ |
42 | #define APP_NAME "RebootDaemon" |
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43 | #define VERSION "1.0" |
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44 | #define REVISION "$Rev: 1158 $" |
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1144 | dev | 45 | |
1145 | dev | 46 | #define DEFAULT_PORT 19 |
47 | #define DEFAULT_CFG_FILE "/etc/rebootdaemon.conf" |
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48 | #define CMDSIZE 4096 |
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49 | #define BUFSIZE 4096 |
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50 | #define MAX_CONFIG_LINE 4096 |
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51 | #define PORT_MIN 1 |
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52 | #define PORT_MAX 65535 |
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1140 | dev | 53 | |
1145 | dev | 54 | /* return values of functions */ |
55 | #define RESULT_OK 0 |
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56 | #define RESULT_EXIT 1 |
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57 | #define RESULT_ERROR 2 |
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58 | #define RESULT_UNEXPECTED 3 |
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1140 | dev | 59 | |
1145 | dev | 60 | /* return values for the whole program */ |
61 | #define EXIT_OK 0 |
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62 | #define EXIT_USER_ERROR 1 |
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63 | #define EXIT_UNEXPECTED 2 |
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64 | |||
65 | /* command line and config file parameters */ |
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66 | #define PARAM_HELP_1 "-h" |
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67 | #define PARAM_HELP_2 "--help" |
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68 | #define PARAM_VERSION_1 "-v" |
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69 | #define PARAM_VERSION_2 "--version" |
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70 | #define PARAM_PORT_1 "-p" |
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71 | #define PARAM_PORT_2 "--port" |
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72 | #define PARAM_CONFIG_1 "-c" |
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73 | #define PARAM_CONFIG_2 "--config" |
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74 | #define CONFIG_PORT "port" |
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75 | #define CONFIG_PASSWORD "password" |
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76 | |||
1140 | dev | 77 | struct config { |
1156 | dev | 78 | ushort port; |
79 | char password[MAX_CONFIG_LINE]; |
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1140 | dev | 80 | }; |
81 | |||
1156 | dev | 82 | static int parse_cmd_line(int argc, const char* argv[], long *port, char *config_name); |
83 | static int parse_config_file(const char *config_name, long *port, char *password); |
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84 | static int get_revision(void); |
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1140 | dev | 85 | |
1156 | dev | 86 | static uint min(uint a, uint b) |
1140 | dev | 87 | { |
88 | return (a < b) ? a : b; |
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89 | } |
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90 | |||
1156 | dev | 91 | static int establish(ushort port) |
1140 | dev | 92 | { |
93 | int s; |
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94 | struct sockaddr_in sa; |
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95 | |||
96 | memset(&sa, 0, sizeof(struct sockaddr_in)); |
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97 | |||
98 | sa.sin_family = AF_INET; |
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1156 | dev | 99 | sa.sin_port = htons(port); |
1140 | dev | 100 | sa.sin_addr.s_addr = INADDR_ANY; |
101 | |||
102 | if((s = socket(AF_INET, SOCK_STREAM, 0)) < 0) |
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103 | return -1; |
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104 | |||
105 | if(bind(s, (struct sockaddr *)&sa, sizeof(struct sockaddr_in)) < 0) { |
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106 | close(s); |
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107 | return -1; |
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108 | } |
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109 | |||
1155 | dev | 110 | if(listen(s, 1) != 0) { |
111 | close(s); |
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112 | return -1; |
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113 | } |
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1140 | dev | 114 | |
115 | return s; |
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116 | } |
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117 | |||
1156 | dev | 118 | static void listen_socket(const struct config *cfg, int soc) |
1142 | dev | 119 | { |
120 | int t; |
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121 | char cmd[CMDSIZE]; |
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122 | char buf[BUFSIZE]; |
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123 | int br; |
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124 | struct sockaddr_in sa; |
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125 | socklen_t sa_len; |
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1155 | dev | 126 | int cmdlen; |
1142 | dev | 127 | |
128 | for(;;) { |
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129 | sa_len = sizeof(sa); |
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1156 | dev | 130 | if((t = accept(soc, (struct sockaddr *)&sa, &sa_len)) < 0) { |
1142 | dev | 131 | if(errno == EINTR) /* EINTR might happen on accept(), */ |
132 | continue; /* try again */ |
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133 | |||
1155 | dev | 134 | syslog(LOG_ERR, "cannot get connection, %s", strerror(errno)); |
1142 | dev | 135 | continue; |
136 | } |
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137 | |||
1155 | dev | 138 | syslog(LOG_INFO, "connect from %s", inet_ntoa(sa.sin_addr)); |
1142 | dev | 139 | |
140 | cmd[0] = '\0'; |
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1155 | dev | 141 | cmdlen = 0; |
1142 | dev | 142 | while((br = recv(t, buf, BUFSIZE, 0)) > 0) { |
1156 | dev | 143 | strncat(cmd, buf, min((uint)br, sizeof(cmd) - cmdlen - 1)); |
144 | cmdlen += min((uint)br, sizeof(cmd) - cmdlen - 1); |
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1142 | dev | 145 | } |
146 | sleep(1); |
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147 | close(t); |
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148 | |||
1147 | dev | 149 | syslog(LOG_INFO, "got command"); |
1142 | dev | 150 | |
1143 | dev | 151 | if(0 == strncmp(cmd, cfg->password, sizeof(cmd))) { |
1142 | dev | 152 | syslog(LOG_EMERG, "REBOOT"); |
153 | sleep(5); |
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154 | if(reboot(RB_AUTOBOOT) < 0) { |
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1155 | dev | 155 | syslog(LOG_ERR, "cannot reboot, %s", strerror(errno)); |
1142 | dev | 156 | } |
157 | } |
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158 | } |
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159 | } |
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160 | |||
1156 | dev | 161 | static void print_version(void) |
1140 | dev | 162 | { |
1145 | dev | 163 | printf("%s %s.%d\n", APP_NAME, VERSION, get_revision()); |
164 | } |
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165 | |||
1156 | dev | 166 | static void pring_usage(int argc, const char* argv[]) |
1145 | dev | 167 | { |
168 | print_version(); |
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169 | printf("\nA daemon which waits on specified TCP port for special string and reboots the computer.\n\n"); |
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170 | printf("Usage: %s [--port PORT] [--config CONFIG_FILE]\n", argv[0]); |
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171 | printf(" or: %s --version\n", argv[0]); |
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172 | printf(" or: %s --help\n\n", argv[0]); |
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173 | printf("Defaults are port 19 and config /etc/rebootdaemon.conf.\n\n"); |
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174 | printf("Config file looks like:\n--------------------------\n"); |
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175 | printf("port=19\npassword=\"some password\"\n--------------------------\n\n"); |
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176 | printf("Then run from any other host:\necho -n \"some password\" | nc host_to_rebot 19\n"); |
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177 | } |
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178 | |||
1156 | dev | 179 | static int print_cmd_error(int argc, const char* argv[], const char *msg, const char *value) |
1145 | dev | 180 | { |
1140 | dev | 181 | fprintf(stderr, "%s", msg); |
182 | if(value) fprintf(stderr, " - %s\n", value); |
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183 | fprintf(stderr, "\n"); |
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184 | |||
1145 | dev | 185 | pring_usage(argc, argv); |
186 | |||
187 | return RESULT_ERROR; |
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1140 | dev | 188 | } |
189 | |||
1156 | dev | 190 | static int print_config_error(const char *config_name, int line, const char *msg, const char *value) |
1140 | dev | 191 | { |
192 | fprintf(stderr, "Error in %s, line %d: %s", config_name, line, msg); |
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193 | if(value) fprintf(stderr, " - %s", value); |
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194 | fprintf(stderr, "\n"); |
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195 | |||
1145 | dev | 196 | return RESULT_ERROR; |
1140 | dev | 197 | } |
198 | |||
1145 | dev | 199 | /* return: 0 - no error, continue; 1 - no error, but exit; 2 - user error, exit; 3 - unexpected error, exit */ |
1156 | dev | 200 | static int read_config(struct config *cfg, int argc, const char* argv[]) |
1140 | dev | 201 | { |
1145 | dev | 202 | int res_cmd_line; |
203 | int res_config_file; |
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1140 | dev | 204 | long cmd_port; |
205 | long file_port; |
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206 | char cmd_config[MAX_CONFIG_LINE]; |
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207 | |||
1145 | dev | 208 | res_cmd_line = parse_cmd_line(argc, argv, &cmd_port, cmd_config); |
209 | if(res_cmd_line != RESULT_OK) return res_cmd_line; |
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1140 | dev | 210 | |
1145 | dev | 211 | res_config_file = parse_config_file(cmd_config[0] != '\0' ? cmd_config : DEFAULT_CFG_FILE, |
212 | &file_port, cfg->password); |
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213 | if(res_config_file != RESULT_OK) return res_config_file; |
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1140 | dev | 214 | |
1143 | dev | 215 | if(cfg->password[0] == '\0') { |
1140 | dev | 216 | fprintf(stderr, "Password is not set\n"); |
1145 | dev | 217 | return RESULT_ERROR; |
1140 | dev | 218 | } |
219 | |||
220 | if(cmd_port > 0) |
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1156 | dev | 221 | cfg->port = (ushort)cmd_port; |
1140 | dev | 222 | else if(file_port > 0) |
1156 | dev | 223 | cfg->port = (ushort)file_port; |
1140 | dev | 224 | else |
1143 | dev | 225 | cfg->port = DEFAULT_PORT; |
1140 | dev | 226 | |
1145 | dev | 227 | return RESULT_OK; |
1140 | dev | 228 | } |
229 | |||
1156 | dev | 230 | static int parse_cmd_line(int argc, const char* argv[], long *port, char *config_name) |
1140 | dev | 231 | { |
232 | char *end; |
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233 | int i; |
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234 | |||
235 | *port = 0; |
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236 | config_name[0] = '\0'; |
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237 | |||
238 | for(i = 1; i < argc; i++) { |
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239 | if(0 == strcmp(argv[i], PARAM_PORT_1) || 0 == strcmp(argv[i], PARAM_PORT_2)) { |
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240 | if(*port > 0) |
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1145 | dev | 241 | return print_cmd_error(argc, argv, "Port is already set", NULL); |
1140 | dev | 242 | |
243 | if(++i < argc) { |
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244 | *port = strtol(argv[i], &end, 10); |
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245 | if(*end != '\0' || *port < PORT_MIN || *port > PORT_MAX) |
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1145 | dev | 246 | return print_cmd_error(argc, argv, |
247 | "Port number must be integer between 1 and 65535", NULL); |
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1140 | dev | 248 | } |
249 | else { |
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1145 | dev | 250 | return print_cmd_error(argc, argv, "Port number expected", NULL); |
1140 | dev | 251 | } |
252 | } |
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253 | else if(0 == strcmp(argv[i], PARAM_CONFIG_1) || 0 == strcmp(argv[i], PARAM_CONFIG_2)) { |
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254 | if(config_name[0] != '\0') |
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1145 | dev | 255 | return print_cmd_error(argc, argv, "Config file is already set", NULL); |
1140 | dev | 256 | |
257 | if(++i < argc) { |
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258 | strncpy(config_name, argv[i], MAX_CONFIG_LINE); |
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259 | if(config_name[MAX_CONFIG_LINE - 1] != '\0') |
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1155 | dev | 260 | return print_cmd_error(argc, argv, |
261 | "Config file name is too long", NULL); |
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1140 | dev | 262 | } |
263 | else { |
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1145 | dev | 264 | return print_cmd_error(argc, argv, "Config file expected", NULL); |
1140 | dev | 265 | } |
266 | } |
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1145 | dev | 267 | else if(0 == strcmp(argv[i], PARAM_VERSION_1) || 0 == strcmp(argv[i], PARAM_VERSION_2)) { |
268 | print_version(); |
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269 | return RESULT_EXIT; |
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270 | } |
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271 | else if(0 == strcmp(argv[i], PARAM_HELP_1) || 0 == strcmp(argv[i], PARAM_HELP_2)) { |
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272 | pring_usage(argc, argv); |
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273 | return RESULT_EXIT; |
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274 | } |
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1140 | dev | 275 | else { |
1145 | dev | 276 | return print_cmd_error(argc, argv, "Unknown parameter", argv[i]); |
1140 | dev | 277 | } |
278 | } |
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279 | |||
1145 | dev | 280 | return RESULT_OK; |
1140 | dev | 281 | } |
282 | |||
283 | |||
1156 | dev | 284 | static int parse_config_file(const char *config_name, long *port, char *password) |
1140 | dev | 285 | { |
286 | FILE *config_file; |
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287 | char buf[MAX_CONFIG_LINE]; |
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288 | char *line; |
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289 | char *subline; |
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290 | char *cur; |
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291 | int count; |
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1156 | dev | 292 | uint len; |
1140 | dev | 293 | |
294 | config_file = fopen(config_name, "r"); |
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295 | if(!config_file) { |
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296 | fprintf(stderr, "Can not open config file %s: %s\n", config_name, strerror(errno)); |
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1145 | dev | 297 | return RESULT_ERROR; |
1140 | dev | 298 | } |
299 | |||
300 | count = 0; |
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301 | while(fgets(buf, sizeof(buf), config_file)) { |
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302 | count++; |
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303 | line = buf; |
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304 | |||
305 | /* skip end spaces */ |
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1156 | dev | 306 | len = strlen(line); |
1146 | dev | 307 | if(len == MAX_CONFIG_LINE-1) |
308 | return print_config_error(config_name, count, "Line is too long", NULL); |
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1140 | dev | 309 | while(len && isspace(line[len-1])) --len; |
310 | if(!len) continue; |
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311 | line[len] = '\0'; |
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312 | |||
313 | /* skip begin spaces */ |
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314 | while(line[0] != '\0' && isspace(line[0])) line++; |
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315 | |||
316 | if('#' == line[0]) { /* skip comment lines */ |
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317 | continue; |
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318 | } |
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319 | else if(strncmp(line, CONFIG_PORT, min(sizeof(CONFIG_PORT) - 1, len)) == 0) { |
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1146 | dev | 320 | subline = line + sizeof(CONFIG_PORT) - 1; |
1145 | dev | 321 | if('=' != subline[0] && !isspace(subline[0])) |
322 | return print_config_error(config_name, count, "Unknown config parameter", line); |
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1140 | dev | 323 | while(subline[0] != '\0' && isspace(subline[0])) subline++; |
324 | if('=' != subline[0]) |
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325 | return print_config_error(config_name, count, "Equal sign expected", NULL); |
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326 | subline++; |
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327 | *port = strtol(subline, &subline, 10); |
||
328 | if(*port < PORT_MIN || *port > PORT_MAX) |
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329 | return print_config_error(config_name, count, |
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330 | "Port number must be integer between 1 and 65535", NULL); |
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331 | while(subline[0] != '\0' && isspace(subline[0])) subline++; |
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332 | if('\0' != subline[0] && '#' != subline[0]) |
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333 | return print_config_error(config_name, count, "End of line expected", NULL); |
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334 | } |
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335 | else if(strncmp(line, CONFIG_PASSWORD, min(sizeof(CONFIG_PASSWORD) - 1, len)) == 0) { |
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1146 | dev | 336 | subline = line + sizeof(CONFIG_PASSWORD) - 1; |
1145 | dev | 337 | if('=' != subline[0] && !isspace(subline[0])) |
338 | return print_config_error(config_name, count, "Unknown config parameter", line); |
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1140 | dev | 339 | while(subline[0] != '\0' && isspace(subline[0])) subline++; |
340 | if('=' != subline[0]) |
||
341 | return print_config_error(config_name, count, "Equal sign expected", NULL); |
||
342 | subline++; |
||
343 | while(subline[0] != '\0' && isspace(subline[0])) subline++; |
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344 | if('"' != subline[0]) |
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345 | return print_config_error(config_name, count, "Open quot expected", NULL); |
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346 | subline++; |
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347 | |||
348 | cur = password; |
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349 | while(subline[0] != '\0' && subline[0] != '"') { |
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350 | cur[0] = subline[0]; |
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351 | cur++; |
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352 | subline++; |
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353 | } |
||
354 | |||
355 | cur[0] = '\0'; |
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356 | if('"' != subline[0]) |
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357 | return print_config_error(config_name, count, "Close quot expected", NULL); |
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358 | subline++; |
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359 | while(subline[0] != '\0' && isspace(subline[0])) subline++; |
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360 | if('\0' != subline[0] && '#' != subline[0]) |
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361 | return print_config_error(config_name, count, "End of line expected", NULL); |
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362 | } |
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363 | else { |
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364 | return print_config_error(config_name, count, "Unknown config parameter", line); |
||
365 | } |
||
366 | } |
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367 | |||
368 | if(fclose(config_file) != 0) { |
||
369 | fprintf(stderr, "Can not close config file %s: %s\n", config_name, strerror(errno)); |
||
1145 | dev | 370 | return RESULT_UNEXPECTED; |
1140 | dev | 371 | } |
372 | |||
1145 | dev | 373 | return RESULT_OK; |
1140 | dev | 374 | } |
375 | |||
1156 | dev | 376 | static int get_revision(void) |
1145 | dev | 377 | { |
1156 | dev | 378 | int r; |
379 | const char *begin; |
||
1145 | dev | 380 | |
381 | begin = REVISION; |
||
382 | while(begin[0] != '\0' && begin[0] != ':') begin++; |
||
383 | if(begin[0] == '\0') return 0; |
||
384 | begin++; |
||
1156 | dev | 385 | r = (int)strtol(begin, (char**)NULL, 10); |
1145 | dev | 386 | |
387 | return r; |
||
388 | } |
||
389 | |||
1156 | dev | 390 | static int create_child(int soc) |
1143 | dev | 391 | { |
392 | pid_t child; |
||
393 | |||
394 | child = fork(); |
||
395 | if(child == -1) { |
||
396 | fprintf(stderr, "Cannot fork: %s\n", strerror(errno)); |
||
1145 | dev | 397 | return RESULT_UNEXPECTED; /* an unexpected error */ |
1143 | dev | 398 | } |
399 | else if(child > 0) { |
||
1156 | dev | 400 | if(close(soc) != 0) { |
1143 | dev | 401 | fprintf(stderr, "Cannot close socket: %s\n", strerror(errno)); |
1145 | dev | 402 | return RESULT_UNEXPECTED; /* an unexpected error */ |
1143 | dev | 403 | } |
1145 | dev | 404 | return RESULT_EXIT; /* we are the parent */ |
1143 | dev | 405 | } |
406 | else { |
||
1145 | dev | 407 | return RESULT_OK; /* we are the child */ |
1143 | dev | 408 | } |
409 | } |
||
410 | |||
411 | static int close_descr(int d) |
||
412 | { |
||
413 | if(close(d) != 0) { |
||
414 | syslog(LOG_ERR, "Cannot close descriptor %d: %s\n", d, strerror(errno)); |
||
1145 | dev | 415 | return RESULT_UNEXPECTED; |
1143 | dev | 416 | } |
1145 | dev | 417 | return RESULT_OK; |
1143 | dev | 418 | } |
419 | |||
1156 | dev | 420 | int main(int argc, const char* argv[]) |
1140 | dev | 421 | { |
1156 | dev | 422 | int soc; |
1143 | dev | 423 | struct config cfg; |
1140 | dev | 424 | |
1143 | dev | 425 | /* get config */ |
1145 | dev | 426 | switch(read_config(&cfg, argc, argv)) { |
1156 | dev | 427 | case RESULT_EXIT: return EXIT_OK; /* no error but exit */ |
428 | case RESULT_ERROR: return EXIT_USER_ERROR; /* user error */ |
||
429 | case RESULT_UNEXPECTED: return EXIT_UNEXPECTED; /* unexpected error */ |
||
1145 | dev | 430 | } |
1143 | dev | 431 | |
432 | /* try to listen the port */ |
||
1156 | dev | 433 | if((soc = establish(cfg.port)) < 0) { |
1140 | dev | 434 | fprintf(stderr, "Cannot listen to port %i\n", cfg.port); |
1145 | dev | 435 | return EXIT_USER_ERROR; |
1140 | dev | 436 | } |
437 | |||
1143 | dev | 438 | /* fork and release the console */ |
1156 | dev | 439 | switch(create_child(soc)) { |
440 | case RESULT_EXIT: return EXIT_OK; /* no error but exit */ |
||
441 | case RESULT_ERROR: return EXIT_USER_ERROR; /* user error */ |
||
442 | case RESULT_UNEXPECTED: return EXIT_UNEXPECTED; /* unexpected error */ |
||
1143 | dev | 443 | } |
1140 | dev | 444 | |
1143 | dev | 445 | /* continue as first child */ |
446 | if(setsid() == -1) { |
||
447 | fprintf(stderr, "Cannot create session: %s\n", strerror(errno)); |
||
1145 | dev | 448 | return EXIT_UNEXPECTED; |
1143 | dev | 449 | } |
450 | |||
451 | /* fork the second time */ |
||
1156 | dev | 452 | switch(create_child(soc)) { |
453 | case RESULT_EXIT: return EXIT_OK; /* no error but exit */ |
||
454 | case RESULT_ERROR: return EXIT_USER_ERROR; /* user error */ |
||
455 | case RESULT_UNEXPECTED: return EXIT_UNEXPECTED; /* unexpected error */ |
||
1143 | dev | 456 | } |
457 | |||
458 | /* continue as final child, from now do not use console for error output */ |
||
459 | chdir("/"); |
||
460 | umask(0); |
||
1145 | dev | 461 | if(close_descr(0) != RESULT_OK) return EXIT_UNEXPECTED; |
462 | if(close_descr(1) != RESULT_OK) return EXIT_UNEXPECTED; |
||
463 | if(close_descr(2) != RESULT_OK) return EXIT_UNEXPECTED; |
||
1143 | dev | 464 | |
465 | syslog(LOG_INFO, "listen on %d", cfg.port); |
||
1156 | dev | 466 | listen_socket(&cfg, soc); |
1143 | dev | 467 | |
1156 | dev | 468 | return EXIT_OK; /* unreachedable */ |
1140 | dev | 469 | } |
470 |