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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 1140 | dev | 1 | /****************************************************************** |
| 2 | * |
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| 3 | * Daemon which waiting on specified TCP port for special string |
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| 4 | * and reboot the computer. |
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| 5 | * |
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| 6 | * Command line: rebootdaemon [--port PORT] [--config CONFIG_FILE] |
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| 7 | * Defaults are port 19 and config /etc/rebootdaemon.conf. |
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| 8 | * |
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| 9 | * Config file looks like: |
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| 10 | * -------------------------- |
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| 11 | * port=19 |
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| 12 | * password="some password" |
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| 13 | * -------------------------- |
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| 14 | * |
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| 15 | * Usage example (from any other host): |
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| 16 | * echo -n "some password" | nc host_to_rebot 19 |
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| 17 | * |
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| 18 | * Copyleft 2005 Anatoli Klassen |
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| 19 | * |
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| 20 | ******************************************************************/ |
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| 21 | |||
| 22 | #include <stdlib.h> |
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| 23 | #include <stdio.h> |
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| 24 | #include <string.h> |
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| 25 | #include <stdarg.h> |
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| 26 | #include <errno.h> |
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| 27 | #include <signal.h> |
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| 28 | #include <unistd.h> |
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| 29 | #include <netdb.h> |
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| 30 | #include <syslog.h> |
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| 31 | #include <sys/types.h> |
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| 32 | #include <sys/socket.h> |
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| 33 | #include <sys/wait.h> |
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| 34 | #include <sys/reboot.h> |
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| 35 | #include <netinet/in.h> |
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| 36 | #include <arpa/inet.h> |
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| 37 | |||
| 38 | #define PORT 19 |
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| 39 | #define CFG_FILE "/etc/rebootdaemon.conf" |
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| 40 | #define CMDSIZE 4096 |
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| 41 | #define BUFSIZE 4096 |
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| 42 | #define MAX_CONFIG_LINE 4096 |
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| 43 | #define PORT_MIN 1 |
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| 44 | #define PORT_MAX 65535 |
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| 45 | |||
| 46 | #define PARAM_PORT_1 "-p" |
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| 47 | #define PARAM_PORT_2 "--port" |
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| 48 | #define PARAM_CONFIG_1 "-c" |
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| 49 | #define PARAM_CONFIG_2 "--config" |
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| 50 | #define CONFIG_PORT "port" |
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| 51 | #define CONFIG_PASSWORD "password" |
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| 52 | |||
| 53 | struct config { |
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| 54 | int port; |
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| 55 | char password[MAX_CONFIG_LINE]; |
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| 56 | }; |
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| 57 | |||
| 58 | static struct config cfg; |
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| 59 | |||
| 60 | static int parse_cmd_line(int argc, char* argv[], long *port, char *config_name); |
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| 61 | static int parse_config_file(char *config_name, long *port, char *password); |
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| 62 | |||
| 63 | static int min(int a, int b) |
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| 64 | { |
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| 65 | return (a < b) ? a : b; |
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| 66 | } |
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| 67 | |||
| 68 | static int establish(unsigned short portnum) |
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| 69 | { |
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| 70 | int s; |
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| 71 | struct sockaddr_in sa; |
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| 72 | |||
| 73 | memset(&sa, 0, sizeof(struct sockaddr_in)); |
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| 74 | |||
| 75 | sa.sin_family = AF_INET; |
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| 76 | sa.sin_port = htons(portnum); |
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| 77 | sa.sin_addr.s_addr = INADDR_ANY; |
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| 78 | |||
| 79 | if((s = socket(AF_INET, SOCK_STREAM, 0)) < 0) |
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| 80 | return -1; |
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| 81 | |||
| 82 | if(bind(s, (struct sockaddr *)&sa, sizeof(struct sockaddr_in)) < 0) { |
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| 83 | close(s); |
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| 84 | return -1; |
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| 85 | } |
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| 86 | |||
| 87 | listen(s, 1); |
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| 88 | |||
| 89 | return s; |
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| 90 | } |
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| 91 | |||
| 92 | static int print_cmd_error(char *msg, char *value) |
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| 93 | { |
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| 94 | fprintf(stderr, "%s", msg); |
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| 95 | if(value) fprintf(stderr, " - %s\n", value); |
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| 96 | fprintf(stderr, "\n"); |
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| 97 | |||
| 98 | return 0; |
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| 99 | } |
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| 100 | |||
| 101 | static int print_config_error(char *config_name, int line, char *msg, char *value) |
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| 102 | { |
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| 103 | fprintf(stderr, "Error in %s, line %d: %s", config_name, line, msg); |
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| 104 | if(value) fprintf(stderr, " - %s", value); |
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| 105 | fprintf(stderr, "\n"); |
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| 106 | |||
| 107 | return 0; |
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| 108 | } |
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| 109 | |||
| 110 | static int read_config(int argc, char* argv[]) |
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| 111 | { |
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| 112 | long cmd_port; |
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| 113 | long file_port; |
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| 114 | char cmd_config[MAX_CONFIG_LINE]; |
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| 115 | |||
| 116 | if(!parse_cmd_line(argc, argv, &cmd_port, cmd_config)) return 0; |
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| 117 | |||
| 118 | if(!parse_config_file(cmd_config[0] != '\0' ? cmd_config : CFG_FILE, &file_port, cfg.password)) return 0; |
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| 119 | |||
| 120 | if(cfg.password[0] == '\0') { |
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| 121 | fprintf(stderr, "Password is not set\n"); |
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| 122 | return 0; |
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| 123 | } |
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| 124 | |||
| 125 | if(cmd_port > 0) |
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| 126 | cfg.port = (int)cmd_port; |
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| 127 | else if(file_port > 0) |
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| 128 | cfg.port = (int)file_port; |
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| 129 | else |
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| 130 | cfg.port = PORT; |
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| 131 | |||
| 132 | return 1; |
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| 133 | } |
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| 134 | |||
| 135 | static int parse_cmd_line(int argc, char* argv[], long *port, char *config_name) |
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| 136 | { |
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| 137 | char *end; |
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| 138 | int i; |
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| 139 | |||
| 140 | *port = 0; |
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| 141 | config_name[0] = '\0'; |
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| 142 | |||
| 143 | for(i = 1; i < argc; i++) { |
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| 144 | if(0 == strcmp(argv[i], PARAM_PORT_1) || 0 == strcmp(argv[i], PARAM_PORT_2)) { |
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| 145 | if(*port > 0) |
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| 146 | return print_cmd_error("Port is already set", NULL); |
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| 147 | |||
| 148 | if(++i < argc) { |
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| 149 | *port = strtol(argv[i], &end, 10); |
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| 150 | if(*end != '\0' || *port < PORT_MIN || *port > PORT_MAX) |
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| 151 | return print_cmd_error("Port number must be integer between 1 and 65535", NULL); |
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| 152 | } |
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| 153 | else { |
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| 154 | return print_cmd_error("Port number expected", NULL); |
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| 155 | } |
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| 156 | } |
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| 157 | else if(0 == strcmp(argv[i], PARAM_CONFIG_1) || 0 == strcmp(argv[i], PARAM_CONFIG_2)) { |
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| 158 | if(config_name[0] != '\0') |
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| 159 | return print_cmd_error("Config file is already set", NULL); |
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| 160 | |||
| 161 | if(++i < argc) { |
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| 162 | strncpy(config_name, argv[i], MAX_CONFIG_LINE); |
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| 163 | if(config_name[MAX_CONFIG_LINE - 1] != '\0') |
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| 164 | return print_cmd_error("Config file name is too long", NULL); |
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| 165 | } |
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| 166 | else { |
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| 167 | return print_cmd_error("Config file expected", NULL); |
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| 168 | } |
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| 169 | } |
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| 170 | else { |
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| 171 | return print_cmd_error("Unknown parameter", argv[i]); |
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| 172 | } |
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| 173 | } |
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| 174 | |||
| 175 | return 1; |
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| 176 | } |
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| 177 | |||
| 178 | |||
| 179 | static int parse_config_file(char *config_name, long *port, char *password) |
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| 180 | { |
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| 181 | FILE *config_file; |
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| 182 | char buf[MAX_CONFIG_LINE]; |
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| 183 | char *line; |
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| 184 | char *subline; |
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| 185 | char *cur; |
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| 186 | int count; |
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| 187 | |||
| 188 | config_file = fopen(config_name, "r"); |
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| 189 | if(!config_file) { |
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| 190 | fprintf(stderr, "Can not open config file %s: %s\n", config_name, strerror(errno)); |
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| 191 | return 0; |
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| 192 | } |
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| 193 | |||
| 194 | count = 0; |
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| 195 | while(fgets(buf, sizeof(buf), config_file)) { |
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| 196 | count++; |
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| 197 | line = buf; |
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| 198 | |||
| 199 | /* skip end spaces */ |
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| 200 | int len = strlen(line); |
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| 201 | while(len && isspace(line[len-1])) --len; |
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| 202 | if(!len) continue; |
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| 203 | line[len] = '\0'; |
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| 204 | |||
| 205 | /* skip begin spaces */ |
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| 206 | while(line[0] != '\0' && isspace(line[0])) line++; |
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| 207 | |||
| 208 | if('#' == line[0]) { /* skip comment lines */ |
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| 209 | continue; |
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| 210 | } |
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| 211 | else if(strncmp(line, CONFIG_PORT, min(sizeof(CONFIG_PORT) - 1, len)) == 0) { |
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| 212 | subline = line + sizeof(CONFIG_PORT) - 1; |
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| 213 | while(subline[0] != '\0' && isspace(subline[0])) subline++; |
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| 214 | if('=' != subline[0]) |
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| 215 | return print_config_error(config_name, count, "Equal sign expected", NULL); |
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| 216 | subline++; |
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| 217 | *port = strtol(subline, &subline, 10); |
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| 218 | if(*port < PORT_MIN || *port > PORT_MAX) |
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| 219 | return print_config_error(config_name, count, |
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| 220 | "Port number must be integer between 1 and 65535", NULL); |
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| 221 | while(subline[0] != '\0' && isspace(subline[0])) subline++; |
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| 222 | if('\0' != subline[0] && '#' != subline[0]) |
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| 223 | return print_config_error(config_name, count, "End of line expected", NULL); |
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| 224 | } |
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| 225 | else if(strncmp(line, CONFIG_PASSWORD, min(sizeof(CONFIG_PASSWORD) - 1, len)) == 0) { |
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| 226 | subline = line + sizeof(CONFIG_PASSWORD) - 1; |
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| 227 | while(subline[0] != '\0' && isspace(subline[0])) subline++; |
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| 228 | if('=' != subline[0]) |
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| 229 | return print_config_error(config_name, count, "Equal sign expected", NULL); |
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| 230 | subline++; |
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| 231 | while(subline[0] != '\0' && isspace(subline[0])) subline++; |
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| 232 | if('"' != subline[0]) |
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| 233 | return print_config_error(config_name, count, "Open quot expected", NULL); |
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| 234 | subline++; |
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| 235 | |||
| 236 | cur = password; |
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| 237 | while(subline[0] != '\0' && subline[0] != '"') { |
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| 238 | cur[0] = subline[0]; |
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| 239 | cur++; |
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| 240 | subline++; |
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| 241 | } |
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| 242 | |||
| 243 | cur[0] = '\0'; |
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| 244 | if('"' != subline[0]) |
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| 245 | return print_config_error(config_name, count, "Close quot expected", NULL); |
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| 246 | subline++; |
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| 247 | while(subline[0] != '\0' && isspace(subline[0])) subline++; |
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| 248 | if('\0' != subline[0] && '#' != subline[0]) |
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| 249 | return print_config_error(config_name, count, "End of line expected", NULL); |
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| 250 | } |
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| 251 | else { |
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| 252 | return print_config_error(config_name, count, "Unknown config parameter", line); |
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| 253 | } |
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| 254 | } |
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| 255 | |||
| 256 | if(fclose(config_file) != 0) { |
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| 257 | fprintf(stderr, "Can not close config file %s: %s\n", config_name, strerror(errno)); |
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| 258 | return 0; |
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| 259 | } |
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| 260 | |||
| 261 | return 1; |
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| 262 | } |
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| 263 | |||
| 264 | int main(int argc, char* argv[]) |
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| 265 | { |
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| 266 | int s, t; |
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| 267 | char cmd[CMDSIZE]; |
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| 268 | char buf[BUFSIZE]; |
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| 269 | char* msg; |
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| 270 | int br; |
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| 271 | struct sockaddr_in sa; |
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| 272 | socklen_t sa_len; |
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| 273 | |||
| 274 | if(!read_config(argc, argv)) return 1; |
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| 275 | |||
| 276 | if((s = establish(cfg.port)) < 0) { |
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| 277 | fprintf(stderr, "Cannot listen to port %i\n", cfg.port); |
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| 278 | return 1; |
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| 279 | } |
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| 280 | |||
| 281 | for(;;) { |
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| 282 | sa_len = sizeof(sa); |
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| 283 | if((t = accept(s, (struct sockaddr *)&sa, &sa_len)) < 0) { |
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| 284 | if(errno == EINTR) /* EINTR might happen on accept(), */ |
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| 285 | continue; /* try again */ |
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| 286 | |||
| 287 | msg = strerror(errno); |
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| 288 | syslog(LOG_ERR, "cannot get connection, %s", msg); |
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| 289 | continue; |
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| 290 | } |
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| 291 | |||
| 292 | msg = inet_ntoa(sa.sin_addr); |
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| 293 | syslog(LOG_INFO, "connect from %s", msg); |
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| 294 | |||
| 295 | cmd[0] = '\0'; |
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| 296 | while((br = recv(t, buf, BUFSIZE, 0)) > 0) { |
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| 297 | strncat(cmd, buf, min(br, sizeof(cmd) - strlen(cmd) - 1)); |
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| 298 | } |
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| 299 | sleep(1); |
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| 300 | close(t); |
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| 301 | |||
| 302 | syslog(LOG_INFO, "got command [%s]", cmd); |
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| 303 | |||
| 304 | if(0 == strncmp(cmd, cfg.password, sizeof(cmd))) { |
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| 305 | syslog(LOG_EMERG, "REBOOT"); |
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| 306 | sleep(5); |
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| 307 | if(reboot(RB_AUTOBOOT) < 0) { |
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| 308 | msg = strerror(errno); |
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| 309 | syslog(LOG_ERR, "cannot reboot, %s", msg); |
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| 310 | } |
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| 311 | } |
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| 312 | } |
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| 313 | |||
| 314 | return 0; |
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| 315 | } |
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| 316 |