X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fconf.c;h=01c3fcd90873081b16030f2dcd4d979087bdda7c;hp=aaa4489911a09ad30cfbe75875a47c9216c084e3;hb=44e9d6a2872fac55f7eb701ba576ed9f39a22e08;hpb=9e55426d72fd77fda891edd0023dab2f9909639e diff --git a/src/conf.c b/src/conf.c index aaa44899..01c3fcd9 100644 --- a/src/conf.c +++ b/src/conf.c @@ -1,9 +1,9 @@ /* conf.c -- configuration code Copyright (C) 1998 Robert van der Meulen - Copyright (C) 1998,1999,2000 Ivo Timmermans - 2000 Guus Sliepen - 2000 Cris van Pelt + 1998-2001 Ivo Timmermans + 2000,2001 Guus Sliepen + 2000 Cris van Pelt 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 @@ -19,7 +19,7 @@ along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - $Id: conf.c,v 1.9.4.25 2000/11/29 14:27:24 zarq Exp $ + $Id: conf.c,v 1.9.4.42 2001/07/24 20:03:40 guus Exp $ */ #include "config.h" @@ -31,6 +31,11 @@ #include #include #include +#include +#include +#include +#include +#include #include #include /* for cp */ @@ -54,26 +59,32 @@ int sighup = 0; */ static internal_config_t hazahaza[] = { /* Main configuration file keywords */ - { "Name", config_name, TYPE_NAME }, { "ConnectTo", config_connectto, TYPE_NAME }, - { "PingTimeout", config_pingtimeout, TYPE_INT }, - { "TapDevice", config_tapdevice, TYPE_NAME }, - { "PrivateKey", config_privatekey, TYPE_NAME }, - { "KeyExpire", config_keyexpire, TYPE_INT }, { "Hostnames", config_hostnames, TYPE_BOOL }, { "Interface", config_interface, TYPE_NAME }, { "InterfaceIP", config_interfaceip, TYPE_IP }, + { "KeyExpire", config_keyexpire, TYPE_INT }, + { "MyVirtualIP", config_dummy, TYPE_IP }, + { "MyOwnVPNIP", config_dummy, TYPE_IP }, + { "Name", config_name, TYPE_NAME }, + { "PingTimeout", config_pingtimeout, TYPE_INT }, + { "PrivateKey", config_privatekey, TYPE_NAME }, + { "PrivateKeyFile", config_privatekeyfile, TYPE_NAME }, + { "TapDevice", config_tapdevice, TYPE_NAME }, + { "VpnMask", config_dummy, TYPE_IP }, /* Host configuration file keywords */ { "Address", config_address, TYPE_NAME }, + { "IndirectData", config_indirectdata, TYPE_BOOL }, { "Port", config_port, TYPE_INT }, { "PublicKey", config_publickey, TYPE_NAME }, - { "Subnet", config_subnet, TYPE_IP }, /* Use IPv4 subnets only for now */ - { "RestrictHosts", config_restricthosts, TYPE_BOOL }, - { "RestrictSubnets", config_restrictsubnets, TYPE_BOOL }, + { "PublicKeyFile", config_publickeyfile, TYPE_NAME }, { "RestrictAddress", config_restrictaddress, TYPE_BOOL }, + { "RestrictHosts", config_restricthosts, TYPE_BOOL }, { "RestrictPort", config_restrictport, TYPE_BOOL }, - { "IndirectData", config_indirectdata, TYPE_BOOL }, + { "RestrictSubnets", config_restrictsubnets, TYPE_BOOL }, + { "Subnet", config_subnet, TYPE_IP }, /* Use IPv4 subnets only for now */ { "TCPonly", config_tcponly, TYPE_BOOL }, + { "Mode", config_mode, TYPE_NAME }, { NULL, 0, 0 } }; @@ -133,8 +144,13 @@ cp 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. */ -char *readline(FILE *fp) +char *readline(FILE *fp, char **buf, size_t *buflen) { char *newline = NULL; char *p; @@ -149,11 +165,21 @@ char *readline(FILE *fp) if(feof(fp)) return NULL; - - size = 100; + + if((buf != NULL) && (buflen != NULL)) + { + size = *buflen; + line = *buf; + } + else + { + size = 100; + line = xmalloc(size); + } + maxlen = size; - line = xmalloc(size); idx = line; + *idx = 0; for(;;) { errno = 0; @@ -186,6 +212,11 @@ char *readline(FILE *fp) } } + if((buf != NULL) && (buflen != NULL)) + { + *buflen = size; + *buf = line; + } return line; } @@ -195,26 +226,39 @@ char *readline(FILE *fp) */ int read_config_file(config_t **base, const char *fname) { - int err = -1; + int err = -2; /* Parse error */ FILE *fp; - char *line; + char *buffer, *line; char *p, *q; - int i, lineno = 0; + int i, lineno = 0, ignore = 0; config_t *cfg; + size_t bufsize; + cp if((fp = fopen (fname, "r")) == NULL) { - return -1; + syslog(LOG_ERR, _("Cannot open config file %s: %m"), fname); + return -3; } + bufsize = 100; + buffer = xmalloc(bufsize); + for(;;) { - if((line = readline(fp)) == NULL) + + if((line = readline(fp, &buffer, &bufsize)) == NULL) { err = -1; break; } - + + if(feof(fp)) + { + err = 0; + break; + } + lineno++; if((p = strtok(line, "\t =")) == NULL) @@ -223,37 +267,47 @@ cp 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; - } - - 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; - } - - 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; - } - - cfg->which = hazahaza[i].which; - if(!config) - config = cfg; + if(!strcmp(p, "-----BEGIN")) + ignore = 1; + + if(ignore == 0) + { + 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 `%s' on line %d while reading config file %s"), + p, lineno, fname); + break; + } + + if(((q = strtok(NULL, "\t\n\r =")) == NULL) || q[0] == '#') + { + syslog(LOG_ERR, _("No value for variable `%s' on line %d while reading config file %s"), + hazahaza[i].name, lineno, fname); + break; + } + + cfg = add_config_val(base, hazahaza[i].argtype, q); + if(cfg == NULL) + { + syslog(LOG_ERR, _("Invalid value for variable `%s' on line %d while reading config file %s"), + hazahaza[i].name, lineno, fname); + break; + } + + cfg->which = hazahaza[i].which; + if(!config) + config = cfg; + } + + if(!strcmp(p, "-----END")) + ignore = 0; } + free(buffer); fclose (fp); cp return err; @@ -266,9 +320,9 @@ int read_server_config() cp asprintf(&fname, "%s/tinc.conf", confbase); x = read_config_file(&config, fname); - if(x != 0) + if(x == -1) /* System error: complain */ { - fprintf(stderr, _("Failed to read `%s': %m\n"), + syslog(LOG_ERR, _("Failed to read `%s': %m"), fname); } free(fname); @@ -309,14 +363,121 @@ cp cp } -#define is_safe_file(p) 1 +int isadir(const char* f) +{ + struct stat s; -FILE *ask_and_safe_open(const char* filename, const char* what) + 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': %m"), + f); + 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': %m"), f); + 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': %m"), + f); + 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': %m"), f); + 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; - int len; /* Check stdin and stdout */ if(!isatty(0) || !isatty(1)) @@ -331,12 +492,14 @@ FILE *ask_and_safe_open(const char* filename, const char* what) /* Ask for a file and/or directory name. */ fprintf(stdout, _("Please enter a file to save %s to [%s]: "), what, filename); - fflush(stdout); /* Don't wait for a newline */ - if((fn = readline(stdin)) == NULL) + fflush(stdout); + + if((fn = readline(stdin, NULL, NULL)) == NULL) { - fprintf(stderr, _("Error while reading stdin: %m\n")); + fprintf(stderr, _("Error while reading stdin: %s\n"), strerror(errno)); return NULL; } + if(strlen(fn) == 0) /* User just pressed enter. */ fn = xstrdup(filename); @@ -348,29 +511,36 @@ FILE *ask_and_safe_open(const char* filename, const char* what) char *p; directory = get_current_dir_name(); - len = strlen(fn) + strlen(directory) + 2; /* 1 for the / */ - p = xmalloc(len); - snprintf(p, len, "%s/%s", directory, fn); + asprintf(&p, "%s/%s", directory, fn); free(fn); + free(directory); fn = p; } - if(!is_safe_file(fn)) + umask(0077); /* Disallow everything for group and other */ + + /* Open it first to keep the inode busy */ + if((r = fopen(fn, mode)) == NULL) + { + 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; } - if((r = fopen(fn, "w")) == NULL) - { - fprintf(stderr, _("Error opening file `%s': %m\n"), - fn); - } - free(fn); - free(directory); - + return r; }