X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fconf.c;h=c4fe101e0231f94e2f3a14a0fe14a20a3f585cb1;hp=37bfe9469639d3fd423ff57566ec97e2ccc96e99;hb=b98d9787fdde54f33dcdb376e1e018cd418aff8d;hpb=3ff76eb10acc55b6f269c1075de6bbaa5bc83516 diff --git a/src/conf.c b/src/conf.c index 37bfe946..c4fe101e 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 1.9.4.23 2000/11/28 23:12:56 zarq Exp $ + $Id: conf.c,v 1.9.4.46 2001/10/27 15:19:13 guus Exp $ */ #include "config.h" @@ -31,17 +31,23 @@ #include #include #include +#include +#include +#include +#include +#include #include #include /* for cp */ +#include #include "conf.h" #include "netutl.h" /* for strtoip */ -#include "config.h" #include "system.h" -config_t *config = NULL; +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 */ @@ -50,157 +56,378 @@ char *netname = NULL; /* name of the vpn network */ /* Will be set if HUP signal is received. It will be processed when it is safe. */ int sighup = 0; -/* - These are all the possible configurable values -*/ -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 }, -/* Host configuration file keywords */ - { "Address", config_address, TYPE_NAME }, - { "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 }, - { "RestrictAddress", config_restrictaddress, TYPE_BOOL }, - { "RestrictPort", config_restrictport, TYPE_BOOL }, - { "IndirectData", config_indirectdata, TYPE_BOOL }, - { "TCPonly", config_tcponly, TYPE_BOOL }, - { NULL, 0, 0 } -}; +int config_compare(config_t *a, config_t *b) +{ + int result; + + result = strcmp(a->variable, b->variable); + + if(result) + return result; -/* - Add given value to the list of configs cfg -*/ -config_t * -add_config_val(config_t **cfg, int argtype, char *val) + result = a->line - b->line; + + if(result) + return result; + else + return strcmp(a->file, b->file); +} + +void init_configuration(avl_tree_t **config_tree) { - config_t *p; - char *q; cp - p = (config_t*)xmalloc(sizeof(*p)); - p->data.val = 0; + *config_tree = avl_alloc_tree((avl_compare_t)config_compare, (avl_action_t)free_config); +cp +} - switch(argtype) +void exit_configuration(avl_tree_t **config_tree) +{ +cp + avl_delete_tree(*config_tree); + *config_tree = NULL; +cp +} + +config_t *new_config(void) +{ + config_t *cfg; +cp + cfg = (config_t *)xmalloc_and_zero(sizeof(*cfg)); + + return cfg; +} + +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); +cp +} + +void config_add(avl_tree_t *config_tree, config_t *cfg) +{ +cp + avl_insert(config_tree, cfg); +cp +} + +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(strcmp(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) { - 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; + if(node->next) + { + found = (config_t *)node->next->data; + if(!strcmp(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, "np")) + { + *result = 0; + return 1; + } + + syslog(LOG_ERR, _("\"yes\" or \"no\" expected for configuration variable %s in %s line %d"), + cfg->value, 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->value, cfg->file, cfg->line); + return 0; +} + +int get_config_string(config_t *cfg, char **result) +{ +cp + if(!cfg) + return 0; + + *result = cfg->value; + return 1; +} + +int get_config_ip(config_t *cfg, ip_mask_t **result) +{ + ip_mask_t *ip; +cp + if(!cfg) + return 0; - p->argtype = argtype; + ip = strtoip(cfg->value); - if(p->data.val) + if(ip) { - p->next = *cfg; - *cfg = p; + *result = ip; + return 1; + } + + syslog(LOG_ERR, _("IP address expected for configuration variable %s in %s line %d"), + cfg->value, cfg->file, cfg->line); + return 0; +} + +int get_config_port(config_t *cfg, port_t *result) +{ cp - return p; + if(!cfg) + return 0; + + if(sscanf(cfg->value, "%hu", result) == 1) + return 1; + + syslog(LOG_ERR, _("Port number expected for configuration variable %s in %s line %d"), + cfg->value, cfg->file, cfg->line); + return 0; +} + +int get_config_subnet(config_t *cfg, subnet_t **result) +{ + ip_mask_t *ip; + subnet_t *subnet; +cp + if(!cfg) + return 0; + + ip = strtoip(cfg->value); + + if(!ip) + { + syslog(LOG_ERR, _("IP address expected for configuration variable %s in %s line %d"), + cfg->value, cfg->file, cfg->line); + return 0; + } + + /* Teach newbies what subnets are... */ + + if((ip->address & ip->mask) != ip->address) + { + syslog(LOG_ERR, _("Network address and subnet mask for configuration variable %s in %s line %d"), + cfg->value, cfg->file, cfg->line); + free(ip); + return 0; + } + + subnet = new_subnet(); + subnet->type = SUBNET_IPV4; + subnet->net.ipv4.address = ip->address; + subnet->net.ipv4.mask = ip->mask; + + free(ip); + + *result = subnet; + + return 1; +} + +/* + 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 **buf, size_t *buflen) +{ + 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 != NULL) && (buflen != NULL)) + { + size = *buflen; + line = *buf; } else { - free(p); -cp - return NULL; + size = 100; + line = xmalloc(size); + } + + maxlen = size; + idx = line; + *idx = 0; + for(;;) + { + errno = 0; + p = fgets(idx, maxlen, fp); + if(p == NULL) /* 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 == NULL) + /* 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 != NULL) && (buflen != NULL)) + { + *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; + int err = -2; /* Parse error */ FILE *fp; - char line[MAXBUFSIZE]; /* There really should not be any line longer than this... */ - char *p, *q; - int i, lineno = 0; + char *buffer, *line; + char *variable, *value; + int 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(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; - } - - if(((q = strtok(NULL, "\t\n\r =")) == NULL) || q[0] == '#') + if((line = readline(fp, &buffer, &bufsize)) == NULL) { - fprintf(stderr, _("No value for variable on line %d while reading config file %s"), - lineno, fname); + err = -1; break; } - cfg = add_config_val(base, hazahaza[i].argtype, q); - if(cfg == NULL) + if(feof(fp)) { - fprintf(stderr, _("Invalid value for variable on line %d while reading config file %s"), - lineno, fname); + err = 0; break; } - cfg->which = hazahaza[i].which; - if(!config) - config = cfg; + lineno++; + + if((variable = strtok(line, "\t =")) == NULL) + continue; /* no tokens on this line */ + + if(variable[0] == '#') + continue; /* comment: ignore */ + + if(!strcmp(variable, "-----BEGIN")) + ignore = 1; + + if(!ignore) + { + if(((value = strtok(NULL, "\t\n\r =")) == NULL) || 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); cp return err; @@ -212,10 +439,10 @@ int read_server_config() int x; cp asprintf(&fname, "%s/tinc.conf", confbase); - x = read_config_file(&config, fname); - if(x != 0) + x = read_config_file(config_tree, fname); + 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); @@ -223,79 +450,184 @@ cp 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 != NULL; p = p->next) - if(p->which == type) - break; -cp - return p; + struct stat s; + + if(stat(f, &s) < 0) + return 0; + else + return S_ISDIR(s.st_mode); } -/* - Remove the complete configuration tree. -*/ -void clear_config(config_t **base) +int is_safe_path(const char *file) { - config_t *p, *next; -cp - for(p = *base; p != NULL; p = next) + 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()) { - next = p->next; - if(p->data.ptr && (p->argtype == TYPE_NAME)) + 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) { - free(p->data.ptr); + syslog(LOG_ERR, _("Unable to read symbolic link `%s': %m"), f); + return 0; } - free(p); + + f = l; + goto check1; } - *base = NULL; -cp -} -#define is_safe_file(p) 1 + *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; + } -FILE *ask_and_safe_open(const char* filename) + 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; - if(!isatty(0)) + /* 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. */ - directory = "."; /* get_current_directory */ + fn = xstrdup(filename); } else { - directory = "."; + /* Ask for a file and/or directory name. */ + fprintf(stdout, _("Please enter a file to save %s to [%s]: "), + what, filename); + fflush(stdout); + + if((fn = readline(stdin, NULL, NULL)) == NULL) + { + fprintf(stderr, _("Error while reading stdin: %s\n"), strerror(errno)); + return NULL; + } + + if(strlen(fn) == 0) + /* User just pressed enter. */ + fn = xstrdup(filename); } - len = strlen(filename) + strlen(directory) + 2; /* 1 for the / */ - fn = xmalloc(len); - snprintf(fn, len, "%s/%s", directory, filename); + if((strchr(fn, '/') == NULL) || (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; + } - 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"), - fn); - } - free(fn); - + return r; }