Use stack-allocated strings for temporary filenames.
[tinc] / src / conf.c
index dc5d2dc..2e13e45 100644 (file)
@@ -2,7 +2,8 @@
     conf.c -- configuration code
     Copyright (C) 1998 Robert van der Meulen
                   1998-2005 Ivo Timmermans
-                  2000-2009 Guus Sliepen <guus@tinc-vpn.org>
+                  2000-2014 Guus Sliepen <guus@tinc-vpn.org>
+                  2010-2011 Julien Muchembled <jm@jmuchemb.eu>
                  2000 Cris van Pelt
 
     This program is free software; you can redistribute it and/or modify
@@ -23,7 +24,9 @@
 #include "system.h"
 
 #include "avl_tree.h"
+#include "connection.h"
 #include "conf.h"
+#include "list.h"
 #include "logger.h"
 #include "netutl.h"                            /* for str2address */
 #include "protocol.h"
@@ -90,7 +93,7 @@ void config_add(avl_tree_t *config_tree, config_t *cfg) {
        avl_insert(config_tree, cfg);
 }
 
-config_t *lookup_config(avl_tree_t *config_tree, char *variable) {
+config_t *lookup_config(const avl_tree_t *config_tree, char *variable) {
        config_t cfg, *found;
 
        cfg.variable = variable;
@@ -108,7 +111,7 @@ config_t *lookup_config(avl_tree_t *config_tree, char *variable) {
        return found;
 }
 
-config_t *lookup_config_next(avl_tree_t *config_tree, const config_t *cfg) {
+config_t *lookup_config_next(const avl_tree_t *config_tree, const config_t *cfg) {
        avl_node_t *node;
        config_t *found;
 
@@ -186,7 +189,7 @@ bool get_config_address(const config_t *cfg, struct addrinfo **result) {
 }
 
 bool get_config_subnet(const config_t *cfg, subnet_t ** result) {
-       subnet_t subnet = {0};
+       subnet_t subnet = {NULL};
 
        if(!cfg)
                return false;
@@ -335,37 +338,156 @@ bool read_config_file(avl_tree_t *config_tree, const char *fname) {
        return result;
 }
 
-bool read_server_config() {
-       list_node_t *node, *next;
-       char *fname;
-       bool x;
+void read_config_options(avl_tree_t *config_tree, const char *prefix) {
+       size_t prefix_len = prefix ? strlen(prefix) : 0;
+
+       for(const list_node_t *node = cmdline_conf->tail; node; node = node->prev) {
+               const config_t *cfg = node->data;
+
+               if(!prefix) {
+                       if(strchr(cfg->variable, '.'))
+                               continue;
+               } else {
+                       if(strncmp(prefix, cfg->variable, prefix_len) ||
+                          cfg->variable[prefix_len] != '.')
+                               continue;
+               }
+
+               config_t *new = new_config();
 
-       for(node = cmdline_conf->tail; node; node = next) {
-               config_t *cfg = (config_t *)node->data;
-               next = node->prev;
-               if (!strchr(cfg->variable, '.')) {
-                       config_add(config_tree, cfg);
-                       node->data = NULL;
-                       list_unlink_node(cmdline_conf, node);
+               if(prefix) {
+                       new->variable = xstrdup(cfg->variable + prefix_len + 1);
+               } else {
+                       new->variable = xstrdup(cfg->variable);
                }
+
+               new->value = xstrdup(cfg->value);
+               new->file = NULL;
+               new->line = cfg->line;
+
+               config_add(config_tree, new);
        }
+}
+
+bool read_server_config(void) {
+       char fname[PATH_MAX];
+       bool x;
 
-       xasprintf(&fname, "%s/tinc.conf", confbase);
+       read_config_options(config_tree, NULL);
+
+       snprintf(fname, sizeof fname, "%s/tinc.conf", confbase);
+       errno = 0;
        x = read_config_file(config_tree, fname);
 
-       if(!x) {                                /* System error: complain */
+       // We will try to read the conf files in the "conf.d" dir
+       if (x) {
+               char dname[PATH_MAX];
+               snprintf(dname, sizeof dname, "%s/conf.d", confbase);
+               DIR *dir = opendir (dname);
+               // If we can find this dir
+               if (dir) { 
+                       struct dirent *ep;
+                       // We list all the files in it
+                       while (x && (ep = readdir (dir))) {
+                               size_t l = strlen(ep->d_name);
+                               // And we try to read the ones that end with ".conf"
+                               if (l > 5 && !strcmp(".conf", & ep->d_name[ l - 5 ])) {
+                                       snprintf(fname, sizeof fname, "%s/%s", dname, ep->d_name);
+                                       x = read_config_file(config_tree, fname);
+                               }
+                       }
+                       closedir (dir);
+               }
+       }
+
+       if(!x && errno) {
                logger(LOG_ERR, "Failed to read `%s': %s", fname, strerror(errno));
        }
 
-       free(fname);
+       return x;
+}
+
+bool read_connection_config(connection_t *c) {
+       char fname[PATH_MAX];
+       bool x;
+
+       read_config_options(c->config_tree, c->name);
+
+       snprintf(fname, sizeof fname, "%s/hosts/%s", confbase, c->name);
+       x = read_config_file(c->config_tree, fname);
 
        return x;
 }
 
+static void disable_old_keys(const char *filename) {
+       char tmpfile[PATH_MAX] = "";
+       char buf[1024];
+       bool disabled = false;
+       FILE *r, *w;
+
+       r = fopen(filename, "r");
+       if(!r)
+               return;
+
+       snprintf(tmpfile, sizeof tmpfile, "%s.tmp", filename);
+
+       w = fopen(tmpfile, "w");
+
+       while(fgets(buf, sizeof buf, r)) {
+               if(!strncmp(buf, "-----BEGIN RSA", 14)) {       
+                       buf[11] = 'O';
+                       buf[12] = 'L';
+                       buf[13] = 'D';
+                       disabled = true;
+               }
+               else if(!strncmp(buf, "-----END RSA", 12)) {    
+                       buf[ 9] = 'O';
+                       buf[10] = 'L';
+                       buf[11] = 'D';
+                       disabled = true;
+               }
+               if(w && fputs(buf, w) < 0) {
+                       disabled = false;
+                       break;
+               }
+       }
+
+       if(w)
+               fclose(w);
+       fclose(r);
+
+       if(!w && disabled) {
+               fprintf(stderr, "Warning: old key(s) found, remove them by hand!\n");
+               return;
+       }
+
+       if(disabled) {
+#ifdef HAVE_MINGW
+               // We cannot atomically replace files on Windows.
+               char bakfile[PATH_MAX] = "";
+               snprintf(bakfile, sizeof bakfile, "%s.bak", filename);
+               if(rename(filename, bakfile) || rename(tmpfile, filename)) {
+                       rename(bakfile, filename);
+#else
+               if(rename(tmpfile, filename)) {
+#endif
+                       fprintf(stderr, "Warning: old key(s) found, remove them by hand!\n");
+               } else  {
+#ifdef HAVE_MINGW
+                       unlink(bakfile);
+#endif
+                       fprintf(stderr, "Warning: old key(s) found and disabled.\n");
+               }
+       }
+
+       unlink(tmpfile);
+}
+
 FILE *ask_and_open(const char *filename, const char *what) {
        FILE *r;
        char *directory;
        char line[PATH_MAX];
+       char abspath[PATH_MAX];
        const char *fn;
 
        /* Check stdin and stdout */
@@ -399,19 +521,19 @@ FILE *ask_and_open(const char *filename, const char *what) {
        if(fn[0] != '/') {
 #endif
                /* The directory is a relative path or a filename. */
-               char *p;
-
                directory = get_current_dir_name();
-               xasprintf(&p, "%s/%s", directory, fn);
+               snprintf(abspath, sizeof abspath, "%s/%s", directory, fn);
                free(directory);
-               fn = p;
+               fn = abspath;
        }
 
        umask(0077);                            /* Disallow everything for group and other */
 
+       disable_old_keys(fn);
+
        /* Open it first to keep the inode busy */
 
-       r = fopen(fn, "r+") ?: fopen(fn, "w+");
+       r = fopen(fn, "a");
 
        if(!r) {
                fprintf(stderr, "Error opening file `%s': %s\n",
@@ -422,33 +544,4 @@ FILE *ask_and_open(const char *filename, const char *what) {
        return r;
 }
 
-bool disable_old_keys(FILE *f) {
-       char buf[100];
-       long pos;
-       bool disabled = false;
-
-       rewind(f);
-       pos = ftell(f);
-
-       while(fgets(buf, sizeof buf, f)) {
-               if(!strncmp(buf, "-----BEGIN RSA", 14)) {       
-                       buf[11] = 'O';
-                       buf[12] = 'L';
-                       buf[13] = 'D';
-                       fseek(f, pos, SEEK_SET);
-                       fputs(buf, f);
-                       disabled = true;
-               }
-               else if(!strncmp(buf, "-----END RSA", 12)) {    
-                       buf[ 9] = 'O';
-                       buf[10] = 'L';
-                       buf[11] = 'D';
-                       fseek(f, pos, SEEK_SET);
-                       fputs(buf, f);
-                       disabled = true;
-               }
-               pos = ftell(f);
-       }
 
-       return disabled;
-}