git ssb

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#include <libconfig.h>
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#include <stdio.h>
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#include <string.h>
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#include <stdlib.h>
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static char* resolve_listen(const char *hostname, const char *port) {
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/* Need room in the strcat for \0 and :
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 * the format in the socket unit file is hostname:port */
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    char *conn = (char*)malloc(strlen(hostname)+strlen(port)+2);
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    strcpy(conn, hostname);
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    strcat(conn, ":");
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    strcat(conn, port);
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    return conn;
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}
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static int get_listen_from_conf(const char *filename, char **listen) {
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  config_t config;
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  config_setting_t *setting, *addr;
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  const char *hostname, *port;
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  int len = 0;
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/* look up the listen stanzas in the config file so these
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 * can be used in the socket file generated */
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  config_init(&config);
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  if (config_read_file(&config, filename) == CONFIG_FALSE) {
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  /* we don't care if file is missing, skip it */
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       if (config_error_line(&config) != 0) {
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       fprintf(stderr, "%s:%d:%s\n",
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                filename,
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                config_error_line(&config),
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                config_error_text(&config));
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        return -1;
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        }
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  } else {
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   setting = config_lookup(&config, "listen");
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    if (setting) {
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      len = config_setting_length(setting);
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      for (int i = 0; i < len; i++) {
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        addr = config_setting_get_elem(setting, i);
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        if (! (config_setting_lookup_string(addr, "host", &hostname) &&
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               config_setting_lookup_string(addr, "port", &port))) {
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          fprintf(stderr,
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            "line %d:Incomplete specification (hostname and port required)\n",
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            config_setting_source_line(addr));
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            return -1;
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         } else {
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        listen[i] = malloc(strlen(resolve_listen(hostname, port)));
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        strcpy(listen[i], resolve_listen(hostname, port));
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        }
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      }
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    }
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  }
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  return len;
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}
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static int write_socket_unit(FILE *socket, char **listen, int num_addr, const char *source) {
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   fprintf(socket,
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        "# Automatically generated by systemd-sslh-generator\n\n"
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        "[Unit]\n"
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        "Before=sslh.service\n"
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        "SourcePath=%s\n"
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        "Documentation=man:sslh(8) man:systemd-sslh-generator(8)\n\n"
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        "[Socket]\n"
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        "FreeBind=true\n",
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        source);
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        for (int i = 0; i < num_addr; i++) {
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            fprintf(socket, "ListenStream=%s\n", listen[i]);
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        }
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return 0;
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}
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static int gen_sslh_config(char *runtime_unit_dir) {
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  char *sslh_conf;
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  int num_addr;
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  FILE *config;
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  char **listen;
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  FILE *runtime_conf_fd = stdout;
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  const char *unit_file;
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/* There are two default locations so check both with first given preference */
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  sslh_conf = "/etc/sslh.cfg";
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  config = fopen(sslh_conf, "r");
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  if (config  == NULL) {
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    sslh_conf="/etc/sslh/sslh.cfg";
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     config = fopen(sslh_conf, "r");
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    if (config == NULL) {
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      return -1;
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    }
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  }
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  fclose(config);
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  num_addr = get_listen_from_conf(sslh_conf, listen);
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  if (num_addr < 0)
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    return -1;
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/* If this is run by systemd directly write to the location told to
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 * otherwise write to standard out so that it's trivial to check what
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 * will be written */
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   if (runtime_unit_dir != "") {
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   unit_file = "/sslh.socket";
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   size_t uf_len = strlen(unit_file);
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   size_t runtime_len = strlen(runtime_unit_dir) + uf_len + 1;
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   char *runtime_conf = malloc(runtime_len);
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       strcpy(runtime_conf, runtime_unit_dir);
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       strcat(runtime_conf, unit_file);
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       runtime_conf_fd = fopen(runtime_conf, "w");
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   }
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 return write_socket_unit(runtime_conf_fd, listen, num_addr, sslh_conf);
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}
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int main(int argc, char *argv[]){
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        int r = 0;
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        int k;
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        char *runtime_unit_dest = "";
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        if (argc > 1 && (argc != 4) ) {
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                printf("This program takes three or no arguments.\n");
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                return -1;
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        }
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        if (argc  > 1)
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            runtime_unit_dest = argv[1];
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        k = gen_sslh_config(runtime_unit_dest);
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        if (k < 0)
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          r = k;
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       return r < 0 ? -1 : 0;
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}
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