+ int err = -2; /* Parse error */
+ FILE *fp;
+ char *buffer, *line;
+ char *variable, *value;
+ int lineno = 0, ignore = 0;
+ config_t *cfg;
+ size_t bufsize;
+
+ cp();
+
+ fp = fopen(fname, "r");
+
+ if(!fp) {
+ syslog(LOG_ERR, _("Cannot open config file %s: %s"), fname,
+ strerror(errno));
+ return -3;
+ }
+
+ bufsize = 100;
+ buffer = xmalloc(bufsize);
+
+ for(;;) {
+ line = readline(fp, &buffer, &bufsize);
+
+ if(!line) {
+ err = -1;
+ break;
+ }
+
+ if(feof(fp)) {
+ err = 0;
+ break;
+ }
+
+ lineno++;
+
+ variable = strtok(line, "\t =");
+
+ if(!variable)
+ continue; /* no tokens on this line */
+
+ if(variable[0] == '#')
+ continue; /* comment: ignore */
+
+ if(!strcmp(variable, "-----BEGIN"))
+ ignore = 1;
+
+ if(!ignore) {
+ value = strtok(NULL, "\t\n\r =");
+
+ if(!value || value[0] == '#') {
+ syslog(LOG_ERR, _("No value for variable `%s' on line %d while reading config file %s"),
+ variable, lineno, fname);
+ break;
+ }
+
+ cfg = new_config();
+ cfg->variable = xstrdup(variable);
+ cfg->value = xstrdup(value);
+ cfg->file = xstrdup(fname);
+ cfg->line = lineno;
+
+ config_add(config_tree, cfg);
+ }
+
+ if(!strcmp(variable, "-----END"))
+ ignore = 0;
+ }
+
+ free(buffer);
+ fclose(fp);
+
+ return err;
+}
+
+int read_server_config()
+{
+ char *fname;
+ int x;
+
+ cp();
+
+ asprintf(&fname, "%s/tinc.conf", confbase);
+ x = read_config_file(config_tree, fname);
+
+ if(x == -1) { /* System error: complain */
+ syslog(LOG_ERR, _("Failed to read `%s': %s"), fname, strerror(errno));
+ }
+
+ free(fname);
+
+ return x;
+}
+
+int isadir(const char *f)
+{
+ struct stat s;
+
+ if(stat(f, &s) < 0)
+ return 0;
+ else
+ return S_ISDIR(s.st_mode);
+}
+
+int is_safe_path(const char *file)
+{
+ char *p;
+ const char *f;
+ char x;
+ struct stat s;
+ char l[MAXBUFSIZE];
+
+ if(*file != '/') {
+ syslog(LOG_ERR, _("`%s' is not an absolute path"), file);
+ return 0;
+ }
+
+ p = strrchr(file, '/');
+
+ if(p == file) /* It's in the root */
+ p++;
+
+ x = *p;
+ *p = '\0';
+
+ f = file;
+
+check1:
+ if(lstat(f, &s) < 0) {
+ syslog(LOG_ERR, _("Couldn't stat `%s': %s"), f, strerror(errno));
+ return 0;
+ }
+
+ if(s.st_uid != geteuid()) {
+ syslog(LOG_ERR, _("`%s' is owned by UID %d instead of %d"),
+ f, s.st_uid, geteuid());
+ return 0;
+ }
+
+ if(S_ISLNK(s.st_mode)) {
+ syslog(LOG_WARNING, _("Warning: `%s' is a symlink"), f);
+
+ if(readlink(f, l, MAXBUFSIZE) < 0) {
+ syslog(LOG_ERR, _("Unable to read symbolic link `%s': %s"), f,
+ strerror(errno));
+ return 0;
+ }
+
+ f = l;
+ goto check1;
+ }
+
+ *p = x;
+ f = file;
+
+check2:
+ if(lstat(f, &s) < 0 && errno != ENOENT) {
+ syslog(LOG_ERR, _("Couldn't stat `%s': %s"), f, strerror(errno));
+ return 0;
+ }
+
+ if(errno == ENOENT)
+ return 1;
+
+ if(s.st_uid != geteuid()) {
+ syslog(LOG_ERR, _("`%s' is owned by UID %d instead of %d"),
+ f, s.st_uid, geteuid());
+ return 0;
+ }
+
+ if(S_ISLNK(s.st_mode)) {
+ syslog(LOG_WARNING, _("Warning: `%s' is a symlink"), f);
+
+ if(readlink(f, l, MAXBUFSIZE) < 0) {
+ syslog(LOG_ERR, _("Unable to read symbolic link `%s': %s"), f,
+ strerror(errno));
+ return 0;
+ }
+
+ f = l;
+ goto check2;
+ }
+
+ if(s.st_mode & 0007) {
+ /* Accessible by others */
+ syslog(LOG_ERR, _("`%s' has unsecure permissions"), f);
+ return 0;
+ }
+
+ return 1;
+}
+
+FILE *ask_and_safe_open(const char *filename, const char *what,
+ const char *mode)
+{
+ FILE *r;
+ char *directory;
+ char *fn;
+
+ /* Check stdin and stdout */
+ if(!isatty(0) || !isatty(1)) {
+ /* Argh, they are running us from a script or something. Write
+ the files to the current directory and let them burn in hell
+ for ever. */
+ fn = xstrdup(filename);
+ } else {
+ /* Ask for a file and/or directory name. */
+ fprintf(stdout, _("Please enter a file to save %s to [%s]: "),
+ what, filename);
+ fflush(stdout);
+
+ fn = readline(stdin, NULL, NULL);
+
+ if(!fn) {
+ fprintf(stderr, _("Error while reading stdin: %s\n"),
+ strerror(errno));
+ return NULL;
+ }
+
+ if(!strlen(fn))
+ /* User just pressed enter. */
+ fn = xstrdup(filename);
+ }
+
+ if(!strchr(fn, '/') || fn[0] != '/') {
+ /* The directory is a relative path or a filename. */
+ char *p;
+
+ directory = get_current_dir_name();
+ asprintf(&p, "%s/%s", directory, fn);
+ free(fn);
+ free(directory);
+ fn = p;
+ }
+
+ umask(0077); /* Disallow everything for group and other */
+
+ /* Open it first to keep the inode busy */
+
+ r = fopen(fn, mode);
+
+ if(!r) {
+ fprintf(stderr, _("Error opening file `%s': %s\n"),
+ fn, strerror(errno));
+ free(fn);
+ return NULL;
+ }
+
+ /* Then check the file for nasty attacks */
+ if(!is_safe_path(fn)) { /* Do not permit any directories that are readable or writeable by other users. */
+ fprintf(stderr, _("The file `%s' (or any of the leading directories) has unsafe permissions.\n"
+ "I will not create or overwrite this file.\n"), fn);
+ fclose(r);
+ free(fn);
+ return NULL;
+ }