/*
conf.c -- configuration code
- Copyright (C) 1998 Emphyrio,
- Copyright (C) 1998,1999,2000 Ivo Timmermans <itimmermans@bigfoot.com>
- 2000 Guus Sliepen <guus@sliepen.warande.net>
- 2000 Cris van Pelt <tribbel@arise.dhs.org>
+ Copyright (C) 1998 Robert van der Meulen
+ 1998-2002 Ivo Timmermans <ivo@o2w.nl>
+ 2000-2002 Guus Sliepen <guus@sliepen.eu.org>
+ 2000 Cris van Pelt <tribbel@arise.dhs.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- $Id: conf.c,v 1.9.4.13 2000/10/14 17:04:12 guus Exp $
+ $Id: conf.c,v 1.9.4.61 2002/09/15 12:26:24 guus Exp $
*/
+#include "config.h"
#include <ctype.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <syslog.h>
+#include <string.h>
#include <xalloc.h>
+#include <utils.h> /* for cp */
+#include <avl_tree.h>
#include "conf.h"
-#include "netutl.h" /* for strtoip */
-#include <utils.h> /* for cp */
+#include "netutl.h" /* for str2address */
-#include "config.h"
-#include "connlist.h"
#include "system.h"
-config_t *config;
+avl_tree_t *config_tree;
+
int debug_lvl = 0;
-int timeout = 0; /* seconds before timeout */
-char *confbase = NULL; /* directory in which all config files are */
+int pingtimeout = 0; /* seconds before timeout */
+char *confbase = NULL; /* directory in which all config files are */
+char *netname = NULL; /* name of the vpn network */
+
+int config_compare(config_t *a, config_t *b)
+{
+ int result;
-/* Will be set if HUP signal is received. It will be processed when it is safe. */
-int sighup = 0;
+ result = strcasecmp(a->variable, b->variable);
-/*
- These are all the possible configurable values
-*/
-static internal_config_t hazahaza[] = {
-/* Main configuration file keywords */
- { "Name", tincname, TYPE_NAME },
- { "ConnectTo", connectto, TYPE_NAME },
- { "PingTimeout", pingtimeout, TYPE_INT },
- { "TapDevice", tapdevice, TYPE_NAME },
- { "PrivateKey", privatekey, TYPE_NAME },
- { "KeyExpire", keyexpire, TYPE_INT },
- { "Hostnames", resolve_dns, TYPE_BOOL },
- { "Interface", interface, TYPE_NAME },
- { "InterfaceIP", interfaceip, TYPE_IP },
-/* Host configuration file keywords */
- { "Address", address, TYPE_NAME },
- { "Port", port, TYPE_INT },
- { "PublicKey", publickey, TYPE_NAME },
- { "Subnet", subnet, TYPE_NAME },
- { "RestrictHosts", restricthosts, TYPE_BOOL },
- { "RestrictSubnets", restrictsubnets, TYPE_BOOL },
- { "RestrictAddress", restrictaddress, TYPE_BOOL },
- { "RestrictPort", restrictport, TYPE_BOOL },
- { "IndirectData", indirectdata, TYPE_BOOL },
- { "TCPonly", tcponly, TYPE_BOOL },
- { NULL, 0, 0 }
-};
+ if(result)
+ return result;
+
+ result = a->line - b->line;
+
+ if(result)
+ return result;
+ else
+ return strcmp(a->file, b->file);
+}
+
+void init_configuration(avl_tree_t ** config_tree)
+{
+ cp();
+
+ *config_tree = avl_alloc_tree((avl_compare_t) config_compare, (avl_action_t) free_config);
+}
+
+void exit_configuration(avl_tree_t ** config_tree)
+{
+ cp();
+
+ avl_delete_tree(*config_tree);
+ *config_tree = NULL;
+}
+
+config_t *new_config(void)
+{
+ cp();
+
+ return (config_t *) xmalloc_and_zero(sizeof(config_t));
+}
+
+void free_config(config_t *cfg)
+{
+ cp();
+
+ if(cfg->variable)
+ free(cfg->variable);
+
+ if(cfg->value)
+ free(cfg->value);
+
+ if(cfg->file)
+ free(cfg->file);
+
+ free(cfg);
+}
+
+void config_add(avl_tree_t *config_tree, config_t *cfg)
+{
+ cp();
+
+ avl_insert(config_tree, cfg);
+}
+
+config_t *lookup_config(avl_tree_t *config_tree, char *variable)
+{
+ config_t cfg, *found;
+
+ cp();
+
+ cfg.variable = variable;
+ cfg.file = "";
+ cfg.line = 0;
+
+ found = avl_search_closest_greater(config_tree, &cfg);
+
+ if(!found)
+ return NULL;
+
+ if(strcasecmp(found->variable, variable))
+ return NULL;
+
+ return found;
+}
+
+config_t *lookup_config_next(avl_tree_t *config_tree, config_t *cfg)
+{
+ avl_node_t *node;
+ config_t *found;
+
+ cp();
+
+ node = avl_search_node(config_tree, cfg);
+
+ if(node) {
+ if(node->next) {
+ found = (config_t *) node->next->data;
+
+ if(!strcasecmp(found->variable, cfg->variable))
+ return found;
+ }
+ }
+
+ return NULL;
+}
+
+int get_config_bool(config_t *cfg, int *result)
+{
+ cp();
+
+ if(!cfg)
+ return 0;
+
+ if(!strcasecmp(cfg->value, "yes")) {
+ *result = 1;
+ return 1;
+ } else if(!strcasecmp(cfg->value, "no")) {
+ *result = 0;
+ return 1;
+ }
+
+ syslog(LOG_ERR, _("\"yes\" or \"no\" expected for configuration variable %s in %s line %d"),
+ cfg->variable, cfg->file, cfg->line);
+
+ return 0;
+}
+
+int get_config_int(config_t *cfg, int *result)
+{
+ cp();
+
+ if(!cfg)
+ return 0;
+
+ if(sscanf(cfg->value, "%d", result) == 1)
+ return 1;
+
+ syslog(LOG_ERR, _("Integer expected for configuration variable %s in %s line %d"),
+ cfg->variable, cfg->file, cfg->line);
+
+ return 0;
+}
+
+int get_config_string(config_t *cfg, char **result)
+{
+ cp();
+
+ if(!cfg)
+ return 0;
+
+ *result = xstrdup(cfg->value);
+
+ return 1;
+}
+
+int get_config_address(config_t *cfg, struct addrinfo **result)
+{
+ struct addrinfo *ai;
+
+ cp();
+
+ if(!cfg)
+ return 0;
+
+ ai = str2addrinfo(cfg->value, NULL, 0);
+
+ if(ai) {
+ *result = ai;
+ return 1;
+ }
+
+ syslog(LOG_ERR, _("Hostname or IP address expected for configuration variable %s in %s line %d"),
+ cfg->variable, cfg->file, cfg->line);
+
+ return 0;
+}
+
+int get_config_subnet(config_t *cfg, subnet_t ** result)
+{
+ subnet_t *subnet;
+
+ cp();
+
+ if(!cfg)
+ return 0;
+
+ subnet = str2net(cfg->value);
+
+ if(!subnet) {
+ syslog(LOG_ERR, _("Subnet expected for configuration variable %s in %s line %d"),
+ cfg->variable, cfg->file, cfg->line);
+ return 0;
+ }
+
+ /* Teach newbies what subnets are... */
+
+ if(((subnet->type == SUBNET_IPV4)
+ && maskcheck(&subnet->net.ipv4.address, subnet->net.ipv4.prefixlength, sizeof(ipv4_t)))
+ || ((subnet->type == SUBNET_IPV6)
+ && maskcheck(&subnet->net.ipv6.address, subnet->net.ipv6.prefixlength, sizeof(ipv6_t)))) {
+ syslog(LOG_ERR, _ ("Network address and prefix length do not match for configuration variable %s in %s line %d"),
+ cfg->variable, cfg->file, cfg->line);
+ free(subnet);
+ return 0;
+ }
+
+ *result = subnet;
+
+ return 1;
+}
/*
- Add given value to the list of configs cfg
+ Read exactly one line and strip the trailing newline if any. If the
+ file was on EOF, return NULL. Otherwise, return all the data in a
+ dynamically allocated buffer.
+
+ If line is non-NULL, it will be used as an initial buffer, to avoid
+ unnecessary mallocing each time this function is called. If buf is
+ given, and buf needs to be expanded, the var pointed to by buflen
+ will be increased.
*/
-config_t *
-add_config_val(config_t **cfg, int argtype, char *val)
+char *readline(FILE * fp, char **buf, size_t *buflen)
{
- config_t *p, *r;
- char *q;
-cp
- p = (config_t*)xmalloc(sizeof(*p));
- p->data.val = 0;
-
- switch(argtype)
- {
- case TYPE_INT:
- p->data.val = strtol(val, &q, 0);
- if(q && *q)
- p->data.val = 0;
- break;
- case TYPE_NAME:
- p->data.ptr = xmalloc(strlen(val) + 1);
- strcpy(p->data.ptr, val);
- break;
- case TYPE_IP:
- p->data.ip = strtoip(val);
- break;
- case TYPE_BOOL:
- if(!strcasecmp("yes", val))
- p->data.val = stupid_true;
- else if(!strcasecmp("no", val))
- p->data.val = stupid_false;
- else
- p->data.val = 0;
- }
-
- p->argtype = argtype;
-
- if(p->data.val)
- {
- if(*cfg)
- {
- r = *cfg;
- while(r->next)
- r = r->next;
- r->next = p;
- }
- else
- *cfg = p;
- p->next = NULL;
- return p;
- }
-
- free(p);
-cp
- return NULL;
+ char *newline = NULL;
+ char *p;
+ char *line; /* The array that contains everything that has been read so far */
+ char *idx; /* Read into this pointer, which points to an offset within line */
+ size_t size, newsize; /* The size of the current array pointed to by line */
+ size_t maxlen; /* Maximum number of characters that may be read with fgets. This is newsize - oldsize. */
+
+ if(feof(fp))
+ return NULL;
+
+ if(buf && buflen) {
+ size = *buflen;
+ line = *buf;
+ } else {
+ size = 100;
+ line = xmalloc(size);
+ }
+
+ maxlen = size;
+ idx = line;
+ *idx = 0;
+
+ for(;;) {
+ errno = 0;
+ p = fgets(idx, maxlen, fp);
+
+ if(!p) { /* EOF or error */
+ if(feof(fp))
+ break;
+
+ /* otherwise: error; let the calling function print an error message if applicable */
+ free(line);
+ return NULL;
+ }
+
+ newline = strchr(p, '\n');
+
+ if(!newline) { /* We haven't yet read everything to the end of the line */
+ newsize = size << 1;
+ line = xrealloc(line, newsize);
+ idx = &line[size - 1];
+ maxlen = newsize - size + 1;
+ size = newsize;
+ } else {
+ *newline = '\0'; /* kill newline */
+ break; /* yay */
+ }
+ }
+
+ if(buf && buflen) {
+ *buflen = size;
+ *buf = line;
+ }
+
+ return line;
}
/*
Parse a configuration file and put the results in the configuration tree
starting at *base.
*/
-int read_config_file(config_t **base, const char *fname)
+int read_config_file(avl_tree_t *config_tree, const char *fname)
{
- int err = -1;
- FILE *fp;
- char line[MAXBUFSIZE]; /* There really should not be any line longer than this... */
- char *p, *q;
- int i, lineno = 0;
- config_t *cfg;
-cp
- if((fp = fopen (fname, "r")) == NULL)
- {
- return -1;
- }
-
- for(;;)
- {
- if(fgets(line, MAXBUFSIZE, fp) == NULL)
- {
- err = 0;
- break;
- }
-
- lineno++;
-
- if(!index(line, '\n'))
- {
- syslog(LOG_ERR, _("Line %d too long while reading config file %s"), lineno, fname);
- break;
- }
-
- if((p = strtok(line, "\t\n\r =")) == NULL)
- continue; /* no tokens on this line */
-
- if(p[0] == '#')
- continue; /* comment: ignore */
-
- for(i = 0; hazahaza[i].name != NULL; i++)
- if(!strcasecmp(hazahaza[i].name, p))
- break;
-
- if(!hazahaza[i].name)
- {
- syslog(LOG_ERR, _("Invalid variable name on line %d while reading config file %s"),
- lineno, fname);
- break;
- }
+ 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();
- if(((q = strtok(NULL, "\t\n\r =")) == NULL) || q[0] == '#')
- {
- fprintf(stderr, _("No value for variable on line %d while reading config file %s"),
- lineno, fname);
- break;
+ fp = fopen(fname, "r");
+
+ if(!fp) {
+ syslog(LOG_ERR, _("Cannot open config file %s: %s"), fname,
+ strerror(errno));
+ return -3;
}
- cfg = add_config_val(base, hazahaza[i].argtype, q);
- if(cfg == NULL)
- {
- fprintf(stderr, _("Invalid value for variable on line %d while reading config file %s"),
- lineno, fname);
- break;
+ 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;
}
- cfg->which = hazahaza[i].which;
- if(!config)
- config = cfg;
- }
+ free(buffer);
+ fclose(fp);
- fclose (fp);
-cp
- return err;
+ return err;
}
int read_server_config()
{
- char *fname;
- int x;
-cp
- asprintf(fname, "%s/tinc.conf", confbase);
- x = read_config_file(&config, fname);
- free(fname);
-cp
- return x;
+ 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;
}
-/*
- Look up the value of the config option type
-*/
-const config_t *get_config_val(config_t *p, which_t type)
+int isadir(const char *f)
{
-cp
- for(p = config; p != NULL; p = p->next)
- if(p->which == type)
- return p;
-cp
- /* Not found */
- return NULL;
+ struct stat s;
+
+ if(stat(f, &s) < 0)
+ return 0;
+ else
+ return S_ISDIR(s.st_mode);
}
-/*
- Support for multiple config lines.
- Index is used to get a specific value, 0 being the first, 1 the second etc.
-*/
-const config_t *get_next_config_val(config_t *p, which_t type, int index)
+int is_safe_path(const char *file)
{
-cp
- for(p = config; p != NULL; p = p->next)
- if(p->which == type)
- if(--index < 0)
- return p;
-cp
- /* Not found */
- return NULL;
+ 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;
}
-/*
- Remove the complete configuration tree.
-*/
-void clear_config(config_t **base)
+FILE *ask_and_safe_open(const char *filename, const char *what,
+ const char *mode)
{
- config_t *p, *next;
-cp
- for(p = *base; p != NULL; p = next)
- {
- next = p->next;
- if(p->data.ptr && (p->argtype == TYPE_NAME))
- {
- free(p->data.ptr);
- }
- free(p);
- }
- *base = NULL;
-cp
+ 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;
+ }
+
+ free(fn);
+
+ return r;
}