diff options
Diffstat (limited to 'configure.c')
-rw-r--r-- | configure.c | 496 |
1 files changed, 496 insertions, 0 deletions
diff --git a/configure.c b/configure.c new file mode 100644 index 0000000..8c024f8 --- /dev/null +++ b/configure.c @@ -0,0 +1,496 @@ +/* + * dhcpcd - DHCP client daemon + * Copyright 2006-2008 Roy Marples <roy@marples.name> + * All rights reserved + + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/stat.h> +#include <sys/wait.h> + +#include <netinet/in.h> +#include <arpa/inet.h> + +#include <ctype.h> +#include <errno.h> +#include <signal.h> +#include <stdlib.h> +#include <unistd.h> + +#include "config.h" +#include "common.h" +#include "configure.h" +#include "dhcp.h" +#include "dhcpcd.h" +#include "logger.h" +#include "net.h" +#include "signals.h" + +#define DEFAULT_PATH "PATH=/usr/bin:/usr/sbin:/bin:/sbin" + +int +exec_script(const struct options *options, const char *iface, + const char *reason, + const struct dhcp_message *dhcpn, const struct dhcp_message *dhcpo) +{ + char *const argv[2] = { UNCONST(options->script), NULL }; + char **env = NULL, **ep; + char *path; + ssize_t e, elen; + int ret = 0; + pid_t pid; + int status = 0; + sigset_t full; + sigset_t old; + + logger(LOG_DEBUG, "executing `%s'", options->script); + + /* Make our env */ + elen = 5; + env = xmalloc(sizeof(char *) * (elen + 1)); + path = getenv("PATH"); + if (path) { + e = strlen("PATH") + strlen(path) + 2; + env[0] = xmalloc(e); + snprintf(env[0], e, "PATH=%s", path); + } else + env[0] = xstrdup(DEFAULT_PATH); + e = strlen("interface") + strlen(iface) + 2; + env[1] = xmalloc(e); + snprintf(env[1], e, "interface=%s", iface); + e = strlen("reason") + strlen(reason) + 2; + env[2] = xmalloc(e); + snprintf(env[2], e, "reason=%s", reason); + e = 20; + env[3] = xmalloc(e); + snprintf(env[3], e, "pid=%d", getpid()); + env[4] = xmalloc(e); + snprintf(env[4], e, "metric=%d", options->metric); + if (dhcpo) { + e = configure_env(NULL, NULL, dhcpo, options); + if (e > 0) { + env = xrealloc(env, sizeof(char *) * (elen + e + 1)); + elen += configure_env(env + elen, "old", dhcpo, options); + } + } + if (dhcpn) { + e = configure_env(NULL, NULL, dhcpn, options); + if (e > 0) { + env = xrealloc(env, sizeof(char *) * (elen + e + 1)); + elen += configure_env(env + elen, "new", dhcpn, options); + } + } + /* Add our base environment */ + if (options->environ) { + e = 0; + while (options->environ[e++]) + ; + env = xrealloc(env, sizeof(char *) * (elen + e + 1)); + e = 0; + while (options->environ[e]) { + env[elen + e] = xstrdup(options->environ[e]); + e++; + } + elen += e; + } + env[elen] = '\0'; + + /* OK, we need to block signals */ + sigfillset(&full); + sigprocmask(SIG_SETMASK, &full, &old); + +#ifdef THERE_IS_NO_FORK + signal_reset(); + pid = vfork(); +#else + pid = fork(); +#endif + + switch (pid) { + case -1: +#ifdef THERE_IS_NO_FORK + logger(LOG_ERR, "vfork: %s", strerror(errno)); +#else + logger(LOG_ERR, "fork: %s", strerror(errno)); +#endif + ret = -1; + break; + case 0: +#ifndef THERE_IS_NO_FORK + signal_reset(); +#endif + sigprocmask(SIG_SETMASK, &old, NULL); + execve(options->script, argv, env); + logger(LOG_ERR, "%s: %s", options->script, strerror(errno)); + _exit(111); + /* NOTREACHED */ + } + +#ifdef THERE_IS_NO_FORK + signal_setup(); +#endif + + /* Restore our signals */ + sigprocmask(SIG_SETMASK, &old, NULL); + + /* Wait for the script to finish */ + while (waitpid(pid, &status, 0) == -1) { + if (errno != EINTR) { + logger(LOG_ERR, "waitpid: %s", strerror(errno)); + status = -1; + break; + } + } + + /* Cleanup */ + ep = env; + while (*ep) + free(*ep++); + free(env); + + return status; +} + +static struct rt * +reverse_routes(struct rt *routes) +{ + struct rt *rt; + struct rt *rtn = NULL; + + while (routes) { + rt = routes->next; + routes->next = rtn; + rtn = routes; + routes = rt; + } + return rtn; +} + +static int +delete_route(const char *iface, struct rt *rt, int metric) +{ + char *addr; + int retval; + + addr = xstrdup(inet_ntoa(rt->dest)); + logger(LOG_DEBUG, "removing route %s/%d via %s", + addr, inet_ntocidr(rt->net), inet_ntoa(rt->gate)); + free(addr); + retval = del_route(iface, &rt->dest, &rt->net, &rt->gate, metric); + if (retval != 0) + logger(LOG_ERR," del_route: %s", strerror(errno)); + return retval; + +} + +static int +delete_routes(struct interface *iface, int metric) +{ + struct rt *rt; + struct rt *rtn; + int retval = 0; + + rt = reverse_routes(iface->routes); + while (rt) { + rtn = rt->next; + retval += delete_route(iface->name, rt, metric); + free(rt); + rt = rtn; + } + iface->routes = NULL; + + return retval; +} + +static int +in_routes(const struct rt *routes, const struct rt *rt) +{ + while (routes) { + if (routes->dest.s_addr == rt->dest.s_addr && + routes->net.s_addr == rt->net.s_addr && + routes->gate.s_addr == rt->gate.s_addr) + return 0; + routes = routes->next; + } + return -1; +} + +static int +configure_routes(struct interface *iface, const struct dhcp_message *dhcp, + const struct options *options) +{ + struct rt *rt, *ort; + struct rt *rtn = NULL, *nr = NULL; + int remember; + int retval = 0; + char *addr; + +#ifdef THERE_IS_NO_FORK + char *skipp; + size_t skiplen; + int skip = 0; + + free(dhcpcd_skiproutes); + /* We can never have more than 255 routes. So we need space + * for 255 3 digit numbers and commas */ + skiplen = 255 * 4 + 1; + skipp = dhcpcd_skiproutes = xmalloc(sizeof(char) * skiplen); + *skipp = '\0'; +#endif + + ort = get_option_routes(dhcp); + +#ifdef ENABLE_IPV4LL_ALWAYSROUTE + if (options->options & DHCPCD_IPV4LL && + IN_PRIVATE(ntohl(dhcp->yiaddr))) + { + for (rt = ort; rt; rt = rt->next) { + /* Check if we have already got a link locale route + * dished out by the DHCP server */ + if (rt->dest.s_addr == htonl(LINKLOCAL_ADDR) && + rt->net.s_addr == htonl(LINKLOCAL_MASK)) + break; + rtn = rt; + } + + if (!rt) { + rt = xmalloc(sizeof(*rt)); + rt->dest.s_addr = htonl(LINKLOCAL_ADDR); + rt->net.s_addr = htonl(LINKLOCAL_MASK); + rt->gate.s_addr = 0; + rt->next = NULL; + if (rtn) + rtn->next = rt; + else + ort = rt; + } + } +#endif + +#ifdef THERE_IS_NO_FORK + if (dhcpcd_skiproutes) { + int i = -1; + char *sk, *skp, *token; + free_routes(iface->routes); + for (rt = ort; rt; rt = rt->next) { + i++; + /* Check that we did add this route or not */ + sk = skp = xstrdup(dhcpcd_skiproutes); + while ((token = strsep(&skp, ","))) { + if (isdigit((unsigned char)*token) && + atoi(token) == i) + break; + } + free(sk); + if (token) + continue; + if (nr) { + rtn->next = xmalloc(sizeof(*rtn)); + rtn = rtn->next; + } else { + nr = rtn = xmalloc(sizeof(*rtn)); + } + rtn->dest.s_addr = rt->dest.s_addr; + rtn->net.s_addr = rt->net.s_addr; + rtn->gate.s_addr = rt->gate.s_addr; + rtn->next = NULL; + } + iface->routes = nr; + nr = NULL; + + /* We no longer need this */ + free(dhcpcd_skiproutes); + dhcpcd_skiproutes = NULL; + } +#endif + + /* Now remove old routes we no longer use. + * We should do this in reverse order. */ + iface->routes = reverse_routes(iface->routes); + for (rt = iface->routes; rt; rt = rt->next) + if (in_routes(ort, rt) != 0) + delete_route(iface->name, rt, options->metric); + + for (rt = ort; rt; rt = rt->next) { + /* Don't set default routes if not asked to */ + if (rt->dest.s_addr == 0 && + rt->net.s_addr == 0 && + !(options->options & DHCPCD_GATEWAY)) + continue; + + addr = xstrdup(inet_ntoa(rt->dest)); + logger(LOG_DEBUG, "adding route to %s/%d via %s", + addr, inet_ntocidr(rt->net), inet_ntoa(rt->gate)); + free(addr); + remember = add_route(iface->name, &rt->dest, + &rt->net, &rt->gate, + options->metric); + retval += remember; + + /* If we failed to add the route, we may have already added it + ourselves. If so, remember it again. */ + if (remember < 0) { + if (errno != EEXIST) + logger(LOG_ERR, "add_route: %s", + strerror(errno)); + if (in_routes(iface->routes, rt) == 0) + remember = 1; + } + + /* This login is split from above due to the #ifdef below */ + if (remember >= 0) { + if (nr) { + rtn->next = xmalloc(sizeof(*rtn)); + rtn = rtn->next; + } else { + nr = rtn = xmalloc(sizeof(*rtn)); + } + rtn->dest.s_addr = rt->dest.s_addr; + rtn->net.s_addr = rt->net.s_addr; + rtn->gate.s_addr = rt->gate.s_addr; + rtn->next = NULL; + } +#ifdef THERE_IS_NO_FORK + /* If we have daemonised yet we need to record which routes + * we failed to add so we can skip them */ + else if (!(options->options & DHCPCD_DAEMONISED)) { + /* We can never have more than 255 / 4 routes, + * so 3 chars is plently */ + printf("foo\n"); + if (*skipp) + *skipp++ = ','; + skipp += snprintf(skipp, + dhcpcd_skiproutes + skiplen - skipp, + "%d", skip); + } + skip++; +#endif + } + free_routes(ort); + free_routes(iface->routes); + iface->routes = nr; + +#ifdef THERE_IS_NO_FORK + if (dhcpcd_skiproutes) { + if (*dhcpcd_skiproutes) + *skipp = '\0'; + else { + free(dhcpcd_skiproutes); + dhcpcd_skiproutes = NULL; + } + } +#endif + + return retval; +} + +int +configure(struct interface *iface, const char *reason, + const struct dhcp_message *dhcp, const struct dhcp_message *old, + const struct dhcp_lease *lease, const struct options *options, + int up) +{ + struct in_addr addr; + struct in_addr net; + struct in_addr brd; +#ifdef __linux__ + struct in_addr dest; + struct in_addr gate; +#endif + + /* Grab our IP config */ + if (dhcp == NULL || dhcp->yiaddr == 0) + up = 0; + else { + addr.s_addr = dhcp->yiaddr; + /* Ensure we have all the needed values */ + if (get_option_addr(&net.s_addr, dhcp, DHCP_SUBNETMASK) == -1) + net.s_addr = get_netmask(addr.s_addr); + if (get_option_addr(&brd.s_addr, dhcp, DHCP_BROADCAST) == -1) + brd.s_addr = addr.s_addr | ~net.s_addr; + } + + /* If we aren't up, then reset the interface as much as we can */ + if (!up) { + /* Only reset things if we had set them before */ + if (iface->addr.s_addr != 0) { + delete_routes(iface, options->metric); + logger(LOG_DEBUG, "deleting IP address %s/%d", + inet_ntoa(iface->addr), + inet_ntocidr(iface->net)); + if (del_address(iface->name, &iface->addr, + &iface->net) == -1 && + errno != ENOENT) + logger(LOG_ERR, "del_address: %s", + strerror(errno)); + iface->addr.s_addr = 0; + iface->net.s_addr = 0; + } + + exec_script(options, iface->name, reason, NULL, old); + return 0; + } + + /* This also changes netmask */ + if (!(options->options & DHCPCD_INFORM) || + !has_address(iface->name, &addr, &net)) { + logger(LOG_DEBUG, "adding IP address %s/%d", + inet_ntoa(addr), inet_ntocidr(net)); + if (add_address(iface->name, &addr, &net, &brd) == -1 && + errno != EEXIST) + { + logger(LOG_ERR, "add_address: %s", strerror(errno)); + return -1; + } + } + + /* Now delete the old address if different */ + if (iface->addr.s_addr != addr.s_addr && + iface->addr.s_addr != 0) + del_address(iface->name, &iface->addr, &iface->net); + +#ifdef __linux__ + /* On linux, we need to change the subnet route to have our metric. */ + if (iface->addr.s_addr != lease->addr.s_addr && + options->metric > 0 && net.s_addr != INADDR_BROADCAST) + { + dest.s_addr = addr.s_addr & net.s_addr; + gate.s_addr = 0; + add_route(iface->name, &dest, &net, &gate, options->metric); + del_route(iface->name, &dest, &net, &gate, 0); + } +#endif + + configure_routes(iface, dhcp, options); + up = (iface->addr.s_addr != addr.s_addr || + iface->net.s_addr != net.s_addr); + iface->addr.s_addr = addr.s_addr; + iface->net.s_addr = net.s_addr; + + if (!lease->frominfo) + if (write_lease(iface, dhcp) == -1) + logger(LOG_ERR, "write_lease: %s", strerror(errno)); + + exec_script(options, iface->name, reason, dhcp, old); + return 0; +} |