script.c - platform/external/dhcpcd-6.8.2 - Git at Google

 /*
  * dhcpcd - DHCP client daemon
  * Copyright (c) 2006-2015 Roy Marples <[email protected]>
  * 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/uio.h>
 #include <sys/wait.h>

 #include <netinet/in.h>
 #include <arpa/inet.h>

 #include <ctype.h>
 #include <errno.h>
 #include <signal.h>
 /* We can't include spawn.h here because it may not exist.
  * config.h will pull it in, or our compat one. */
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>

 #include "config.h"
 #include "common.h"
 #include "dhcp.h"
 #include "dhcp6.h"
 #include "if.h"
 #include "if-options.h"
 #include "ipv6nd.h"
 #include "script.h"

 #ifdef HAVE_SPAWN_H
 #include <spawn.h>
 #else
 #include "compat/posix_spawn.h"
 #endif

 /* Allow the OS to define another script env var name */
 #ifndef RC_SVCNAME
 #define RC_SVCNAME "RC_SVCNAME"
 #endif

 #define DEFAULT_PATH	"PATH=/usr/bin:/usr/sbin:/bin:/sbin"

 static const char * const if_params[] = {
 	"interface",
 	"reason",
 	"pid",
 	"ifcarrier",
 	"ifmetric",
 	"ifwireless",
 	"ifflags",
 	"ssid",
 	"profile",
 	"interface_order",
 	NULL
 };

 void
 if_printoptions(void)
 {
 	const char * const *p;

 	for (p = if_params; *p; p++)
 		printf(" -  %s\n", *p);
 }

 static int
 exec_script(const struct dhcpcd_ctx *ctx, char *const *argv, char *const *env)
 {
 	pid_t pid;
 	posix_spawnattr_t attr;
 	int i;
 #ifdef USE_SIGNALS
 	short flags;
 	sigset_t defsigs;
 #else
 	UNUSED(ctx);
 #endif

 	/* posix_spawn is a safe way of executing another image
 	 * and changing signals back to how they should be. */
 	if (posix_spawnattr_init(&attr) == -1)
 		return -1;
 #ifdef USE_SIGNALS
 	flags = POSIX_SPAWN_SETSIGMASK | POSIX_SPAWN_SETSIGDEF;
 	posix_spawnattr_setflags(&attr, flags);
 	sigemptyset(&defsigs);
 	for (i = 0; dhcpcd_handlesigs[i]; i++)
 		sigaddset(&defsigs, dhcpcd_handlesigs[i]);
 	posix_spawnattr_setsigdefault(&attr, &defsigs);
 	posix_spawnattr_setsigmask(&attr, &ctx->sigset);
 #endif
 	errno = 0;
 	i = posix_spawn(&pid, argv[0], NULL, &attr, argv, env);
 	if (i) {
 		errno = i;
 		return -1;
 	}
 	return pid;
 }

 #ifdef INET
 static char *
 make_var(struct dhcpcd_ctx *ctx, const char *prefix, const char *var)
 {
 	size_t len;
 	char *v;

 	len = strlen(prefix) + strlen(var) + 2;
 	v = malloc(len);
 	if (v == NULL) {
 		logger(ctx, LOG_ERR, "%s: %m", __func__);
 		return NULL;
 	}
 	snprintf(v, len, "%s_%s", prefix, var);
 	return v;
 }


 static int
 append_config(struct dhcpcd_ctx *ctx, char ***env, size_t *len,
     const char *prefix, const char *const *config)
 {
 	size_t i, j, e1;
 	char **ne, *eq, **nep, *p;
 	int ret;

 	if (config == NULL)
 		return 0;

 	ne = *env;
 	ret = 0;
 	for (i = 0; config[i] != NULL; i++) {
 		eq = strchr(config[i], '=');
 		e1 = (size_t)(eq - config[i] + 1);
 		for (j = 0; j < *len; j++) {
 			if (strncmp(ne[j] + strlen(prefix) + 1,
 				config[i], e1) == 0)
 			{
 				p = make_var(ctx, prefix, config[i]);
 				if (p == NULL) {
 					ret = -1;
 					break;
 				}
 				free(ne[j]);
 				ne[j] = p;
 				break;
 			}
 		}
 		if (j == *len) {
 			j++;
 			p = make_var(ctx, prefix, config[i]);
 			if (p == NULL) {
 				ret = -1;
 				break;
 			}
 			nep = realloc(ne, sizeof(char *) * (j + 1));
 			if (nep == NULL) {
 				logger(ctx, LOG_ERR, "%s: %m", __func__);
 				free(p);
 				ret = -1;
 				break;
 			}
 			ne = nep;
 			ne[j - 1] = p;
 			*len = j;
 		}
 	}
 	*env = ne;
 	return ret;
 }
 #endif

 static ssize_t
 arraytostr(const char *const *argv, char **s)
 {
 	const char *const *ap;
 	char *p;
 	size_t len, l;

 	if (*argv == NULL)
 		return 0;
 	len = 0;
 	ap = argv;
 	while (*ap)
 		len += strlen(*ap++) + 1;
 	*s = p = malloc(len);
 	if (p == NULL)
 		return -1;
 	ap = argv;
 	while (*ap) {
 		l = strlen(*ap) + 1;
 		memcpy(p, *ap, l);
 		p += l;
 		ap++;
 	}
 	return (ssize_t)len;
 }

 static ssize_t
 make_env(const struct interface *ifp, const char *reason, char ***argv)
 {
 	char **env, **nenv, *p;
 	size_t e, elen, l;
 #if defined(INET) || defined(INET6)
 	ssize_t n;
 #endif
 	const struct if_options *ifo = ifp->options;
 	const struct interface *ifp2;
 #ifdef INET
 	int dhcp;
 	const struct dhcp_state *state;
 #endif
 #ifdef INET6
 	const struct dhcp6_state *d6_state;
 	int dhcp6, ra;
 #endif

 #ifdef INET
 	dhcp = 0;
 	state = D_STATE(ifp);
 #endif
 #ifdef INET6
 	dhcp6 = ra = 0;
 	d6_state = D6_CSTATE(ifp);
 #endif
 	if (strcmp(reason, "TEST") == 0) {
 		if (1 == 2) {}
 #ifdef INET6
 		else if (d6_state && d6_state->new)
 			dhcp6 = 1;
 		else if (ipv6nd_hasra(ifp))
 			ra = 1;
 #endif
 #ifdef INET
 		else
 			dhcp = 1;
 #endif
 	}
 #ifdef INET6
 	else if (reason[strlen(reason) - 1] == '6')
 		dhcp6 = 1;
 	else if (strcmp(reason, "ROUTERADVERT") == 0)
 		ra = 1;
 #endif
 	else if (strcmp(reason, "PREINIT") == 0 ||
 	    strcmp(reason, "CARRIER") == 0 ||
 	    strcmp(reason, "NOCARRIER") == 0 ||
 	    strcmp(reason, "UNKNOWN") == 0 ||
 	    strcmp(reason, "DEPARTED") == 0 ||
 	    strcmp(reason, "STOPPED") == 0)
 	{
 		/* This space left intentionally blank */
 	}
 #ifdef INET
 	else
 		dhcp = 1;
 #endif

 	/* When dumping the lease, we only want to report interface and
 	   reason - the other interface variables are meaningless */
 	if (ifp->ctx->options & DHCPCD_DUMPLEASE)
 		elen = 2;
 	else
 		elen = 13;

 #define EMALLOC(i, l) if ((env[(i)] = malloc((l))) == NULL) goto eexit;
 	/* Make our env + space for profile, wireless and debug */
 	env = calloc(1, sizeof(char *) * (elen + 3 + 1));
 	if (env == NULL)
 		goto eexit;
 	e = strlen("interface") + strlen(ifp->name) + 2;
 	EMALLOC(0, e);
 	snprintf(env[0], e, "interface=%s", ifp->name);
 	e = strlen("reason") + strlen(reason) + 2;
 	EMALLOC(1, e);
 	snprintf(env[1], e, "reason=%s", reason);
 	if (ifp->ctx->options & DHCPCD_DUMPLEASE)
 		goto dumplease;
 	e = 20;
 	EMALLOC(2, e);
 	snprintf(env[2], e, "pid=%d", getpid());
 	EMALLOC(3, e);
 	snprintf(env[3], e, "ifcarrier=%s",
 	    ifp->carrier == LINK_UNKNOWN ? "unknown" :
 	    ifp->carrier == LINK_UP ? "up" : "down");
 	EMALLOC(4, e);
 	snprintf(env[4], e, "ifmetric=%d", ifp->metric);
 	EMALLOC(5, e);
 	snprintf(env[5], e, "ifwireless=%d", ifp->wireless);
 	EMALLOC(6, e);
 	snprintf(env[6], e, "ifflags=%u", ifp->flags);
 	EMALLOC(7, e);
 	snprintf(env[7], e, "ifmtu=%d", if_getmtu(ifp->name));
 	l = e = strlen("interface_order=");
 	TAILQ_FOREACH(ifp2, ifp->ctx->ifaces, next) {
 		if (!(ifp2->options->options & DHCPCD_PFXDLGONLY))
 			e += strlen(ifp2->name) + 1;
 	}
 	EMALLOC(8, e);
 	p = env[8];
 	strlcpy(p, "interface_order=", e);
 	e -= l;
 	p += l;
 	TAILQ_FOREACH(ifp2, ifp->ctx->ifaces, next) {
 		if (!(ifp2->options->options & DHCPCD_PFXDLGONLY)) {
 			l = strlcpy(p, ifp2->name, e);
 			p += l;
 			e -= l;
 			*p++ = ' ';
 			e--;
 		}
 	}
 	*--p = '\0';
 	if (strcmp(reason, "STOPPED") == 0) {
 		env[9] = strdup("if_up=false");
 		if (ifo->options & DHCPCD_RELEASE)
 			env[10] = strdup("if_down=true");
 		else
 			env[10] = strdup("if_down=false");
 	} else if (strcmp(reason, "TEST") == 0 ||
 	    strcmp(reason, "PREINIT") == 0 ||
 	    strcmp(reason, "CARRIER") == 0 ||
 	    strcmp(reason, "UNKNOWN") == 0)
 	{
 		env[9] = strdup("if_up=false");
 		env[10] = strdup("if_down=false");
 	} else if (1 == 2 /* appease ifdefs */
 #ifdef INET
 	    || (dhcp && state && state->new)
 #endif
 #ifdef INET6
 	    || (dhcp6 && d6_state && d6_state->new)
 	    || (ra && ipv6nd_hasra(ifp))
 #endif
 	    )
 	{
 		env[9] = strdup("if_up=true");
 		env[10] = strdup("if_down=false");
 	} else {
 		env[9] = strdup("if_up=false");
 		env[10] = strdup("if_down=true");
 	}
 	if (env[9] == NULL || env[10] == NULL)
 		goto eexit;
 	if (dhcpcd_oneup(ifp->ctx))
 		env[11] = strdup("if_oneup=true");
 	else
 		env[11] = strdup("if_oneup=false");
 	if (env[11] == NULL)
 		goto eexit;
 	if (dhcpcd_ipwaited(ifp->ctx))
 		env[12] = strdup("if_ipwaited=true");
 	else
 		env[12] = strdup("if_ipwaited=false");
 	if (env[12] == NULL)
 		goto eexit;
 	if (ifo->options & DHCPCD_DEBUG) {
 		e = strlen("syslog_debug=true") + 1;
 		EMALLOC(elen, e);
 		snprintf(env[elen++], e, "syslog_debug=true");
 	}
 	if (*ifp->profile) {
 		e = strlen("profile=") + strlen(ifp->profile) + 1;
 		EMALLOC(elen, e);
 		snprintf(env[elen++], e, "profile=%s", ifp->profile);
 	}
 	if (ifp->wireless) {
 		static const char *pfx = "ifssid=";
 		size_t pfx_len;
 		ssize_t psl;

 		pfx_len = strlen(pfx);
 		psl = print_string(NULL, 0, ESCSTRING,
 		    (const uint8_t *)ifp->ssid, ifp->ssid_len);
 		if (psl != -1) {
 			EMALLOC(elen, pfx_len + (size_t)psl + 1);
 			memcpy(env[elen], pfx, pfx_len);
 			print_string(env[elen] + pfx_len, (size_t)psl + 1,
 			    ESCSTRING,
 			    (const uint8_t *)ifp->ssid, ifp->ssid_len);
 			elen++;
 		}
 	}
 #ifdef INET
 	if (dhcp && state && state->old) {
 		n = dhcp_env(NULL, NULL, state->old, ifp);
 		if (n == -1)
 			goto eexit;
 		if (n > 0) {
 			nenv = realloc(env, sizeof(char *) *
 			    (elen + (size_t)n + 1));
 			if (nenv == NULL)
 				goto eexit;
 			env = nenv;
 			n = dhcp_env(env + elen, "old", state->old, ifp);
 			if (n == -1)
 				goto eexit;
 			elen += (size_t)n;
 		}
 		if (append_config(ifp->ctx, &env, &elen, "old",
 		    (const char *const *)ifo->config) == -1)
 			goto eexit;
 	}
 #endif
 #ifdef INET6
 	if (dhcp6 && d6_state && ifo->options & DHCPCD_PFXDLGONLY) {
 		nenv = realloc(env, sizeof(char *) * (elen + 2));
 		if (nenv == NULL)
 			goto eexit;
 		env = nenv;
 		env[elen] = strdup("ifclass=pd");
 		if (env[elen] == NULL)
 			goto eexit;
 		elen++;
 	}
 	if (dhcp6 && d6_state && d6_state->old) {
 		n = dhcp6_env(NULL, NULL, ifp,
 		    d6_state->old, d6_state->old_len);
 		if (n > 0) {
 			nenv = realloc(env, sizeof(char *) *
 			    (elen + (size_t)n + 1));
 			if (nenv == NULL)
 				goto eexit;
 			env = nenv;
 			n = dhcp6_env(env + elen, "old", ifp,
 			    d6_state->old, d6_state->old_len);
 			if (n == -1)
 				goto eexit;
 			elen += (size_t)n;
 		}
 	}
 #endif

 dumplease:
 #ifdef INET
 	if (dhcp && state && state->new) {
 		n = dhcp_env(NULL, NULL, state->new, ifp);
 		if (n > 0) {
 			nenv = realloc(env, sizeof(char *) *
 			    (elen + (size_t)n + 1));
 			if (nenv == NULL)
 				goto eexit;
 			env = nenv;
 			n = dhcp_env(env + elen, "new",
 			    state->new, ifp);
 			if (n == -1)
 				goto eexit;
 			elen += (size_t)n;
 		}
 		if (append_config(ifp->ctx, &env, &elen, "new",
 		    (const char *const *)ifo->config) == -1)
 			goto eexit;
 	}
 #endif
 #ifdef INET6
 	if (dhcp6 && D6_STATE_RUNNING(ifp)) {
 		n = dhcp6_env(NULL, NULL, ifp,
 		    d6_state->new, d6_state->new_len);
 		if (n > 0) {
 			nenv = realloc(env, sizeof(char *) *
 			    (elen + (size_t)n + 1));
 			if (nenv == NULL)
 				goto eexit;
 			env = nenv;
 			n = dhcp6_env(env + elen, "new", ifp,
 			    d6_state->new, d6_state->new_len);
 			if (n == -1)
 				goto eexit;
 			elen += (size_t)n;
 		}
 	}
 	if (ra) {
 		n = ipv6nd_env(NULL, NULL, ifp);
 		if (n > 0) {
 			nenv = realloc(env, sizeof(char *) *
 			    (elen + (size_t)n + 1));
 			if (nenv == NULL)
 				goto eexit;
 			env = nenv;
 			n = ipv6nd_env(env + elen, NULL, ifp);
 			if (n == -1)
 				goto eexit;
 			elen += (size_t)n;
 		}
 	}
 #endif

 	/* Add our base environment */
 	if (ifo->environ) {
 		e = 0;
 		while (ifo->environ[e++])
 			;
 		nenv = realloc(env, sizeof(char *) * (elen + e + 1));
 		if (nenv == NULL)
 			goto eexit;
 		env = nenv;
 		e = 0;
 		while (ifo->environ[e]) {
 			env[elen + e] = strdup(ifo->environ[e]);
 			if (env[elen + e] == NULL)
 				goto eexit;
 			e++;
 		}
 		elen += e;
 	}
 	env[elen] = NULL;

 	*argv = env;
 	return (ssize_t)elen;

 eexit:
 	logger(ifp->ctx, LOG_ERR, "%s: %m", __func__);
 	if (env) {
 		nenv = env;
 		while (*nenv)
 			free(*nenv++);
 		free(env);
 	}
 	return -1;
 }

 static int
 send_interface1(struct fd_list *fd, const struct interface *iface,
     const char *reason)
 {
 	char **env, **ep, *s;
 	size_t elen;
 	int retval;

 	if (make_env(iface, reason, &env) == -1)
 		return -1;
 	s = NULL;
 	elen = (size_t)arraytostr((const char *const *)env, &s);
 	if ((ssize_t)elen == -1) {
 		free(s);
 		return -1;
 	}
 	retval = control_queue(fd, s, elen, 1);
 	ep = env;
 	while (*ep)
 		free(*ep++);
 	free(env);
 	return retval;
 }

 int
 send_interface(struct fd_list *fd, const struct interface *ifp)
 {
 	const char *reason;
 	int retval = 0;
 #ifdef INET
 	const struct dhcp_state *d;
 #endif
 #ifdef INET6
 	const struct dhcp6_state *d6;
 #endif

 	switch (ifp->carrier) {
 	case LINK_UP:
 		reason = "CARRIER";
 		break;
 	case LINK_DOWN:
 		reason = "NOCARRIER";
 		break;
 	default:
 		reason = "UNKNOWN";
 		break;
 	}
 	if (send_interface1(fd, ifp, reason) == -1)
 		retval = -1;
 #ifdef INET
 	if (D_STATE_RUNNING(ifp)) {
 		d = D_CSTATE(ifp);
 		if (send_interface1(fd, ifp, d->reason) == -1)
 			retval = -1;
 	}
 #endif

 #ifdef INET6
 	if (RS_STATE_RUNNING(ifp)) {
 		if (send_interface1(fd, ifp, "ROUTERADVERT") == -1)
 			retval = -1;
 	}
 	if (D6_STATE_RUNNING(ifp)) {
 		d6 = D6_CSTATE(ifp);
 		if (send_interface1(fd, ifp, d6->reason) == -1)
 			retval = -1;
 	}
 #endif

 	return retval;
 }

 int
 script_runreason(const struct interface *ifp, const char *reason)
 {
 	char *argv[2];
 	char **env = NULL, **ep;
 	char *svcname, *path, *bigenv;
 	size_t e, elen = 0;
 	pid_t pid;
 	int status = 0;
 	struct fd_list *fd;

 	if (ifp->options->script &&
 	    (ifp->options->script[0] == '\0' ||
 	    strcmp(ifp->options->script, "/dev/null") == 0))
 		return 0;

 	argv[0] = ifp->options->script ? ifp->options->script : UNCONST(SCRIPT);
 	argv[1] = NULL;
 	logger(ifp->ctx, LOG_DEBUG, "%s: executing `%s' %s",
 	    ifp->name, argv[0], reason);

 	/* Make our env */
 	elen = (size_t)make_env(ifp, reason, &env);
 	if (elen == (size_t)-1) {
 		logger(ifp->ctx, LOG_ERR, "%s: make_env: %m", ifp->name);
 		return -1;
 	}
 	/* Resize for PATH and RC_SVCNAME */
 	svcname = getenv(RC_SVCNAME);
 	ep = realloc(env, sizeof(char *) * (elen + 2 + (svcname ? 1 : 0)));
 	if (ep == NULL) {
 		elen = 0;
 		goto out;
 	}
 	env = ep;
 	/* Add path to it */
 	path = getenv("PATH");
 	if (path) {
 		e = strlen("PATH") + strlen(path) + 2;
 		env[elen] = malloc(e);
 		if (env[elen] == NULL) {
 			elen = 0;
 			goto out;
 		}
 		snprintf(env[elen], e, "PATH=%s", path);
 	} else {
 		env[elen] = strdup(DEFAULT_PATH);
 		if (env[elen] == NULL) {
 			elen = 0;
 			goto out;
 		}
 	}
 	if (svcname) {
 		e = strlen(RC_SVCNAME) + strlen(svcname) + 2;
 		env[++elen] = malloc(e);
 		if (env[elen] == NULL) {
 			elen = 0;
 			goto out;
 		}
 		snprintf(env[elen], e, "%s=%s", RC_SVCNAME, svcname);
 	}
 	env[++elen] = NULL;

 	pid = exec_script(ifp->ctx, argv, env);
 	if (pid == -1)
 		logger(ifp->ctx, LOG_ERR, "%s: %s: %m", __func__, argv[0]);
 	else if (pid != 0) {
 		/* Wait for the script to finish */
 		while (waitpid(pid, &status, 0) == -1) {
 			if (errno != EINTR) {
 				logger(ifp->ctx, LOG_ERR, "waitpid: %m");
 				status = 0;
 				break;
 			}
 		}
 		if (WIFEXITED(status)) {
 			if (WEXITSTATUS(status))
 				logger(ifp->ctx, LOG_ERR,
 				    "%s: %s: WEXITSTATUS %d",
 				    __func__, argv[0], WEXITSTATUS(status));
 		} else if (WIFSIGNALED(status))
 			logger(ifp->ctx, LOG_ERR, "%s: %s: %s",
 			    __func__, argv[0], strsignal(WTERMSIG(status)));
 	}

 	/* Send to our listeners */
 	bigenv = NULL;
 	status = 0;
 	TAILQ_FOREACH(fd, &ifp->ctx->control_fds, next) {
 		if (!(fd->flags & FD_LISTEN))
 			continue;
 		if (bigenv == NULL) {
 			elen = (size_t)arraytostr((const char *const *)env,
 			    &bigenv);
 			if ((ssize_t)elen == -1) {
 				logger(ifp->ctx, LOG_ERR, "%s: arraytostr: %m",
 				    ifp->name);
 				    break;
 			}
 		}
 		if (control_queue(fd, bigenv, elen, 1) == -1)
 			logger(ifp->ctx, LOG_ERR,
 			    "%s: control_queue: %m", __func__);
 		else
 			status = 1;
 	}
 	if (!status)
 		free(bigenv);

 out:
 	/* Cleanup */
 	ep = env;
 	while (*ep)
 		free(*ep++);
 	free(env);
 	if (elen == 0)
 		return -1;
 	return WEXITSTATUS(status);
 }
	/*
	* dhcpcd - DHCP client daemon
	* Copyright (c) 2006-2015 Roy Marples <[email protected]>
	* 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/uio.h>
	#include <sys/wait.h>

	#include <netinet/in.h>
	#include <arpa/inet.h>

	#include <ctype.h>
	#include <errno.h>
	#include <signal.h>
	/* We can't include spawn.h here because it may not exist.
	* config.h will pull it in, or our compat one. */
	#include <stdlib.h>
	#include <string.h>
	#include <unistd.h>

	#include "config.h"
	#include "common.h"
	#include "dhcp.h"
	#include "dhcp6.h"
	#include "if.h"
	#include "if-options.h"
	#include "ipv6nd.h"
	#include "script.h"

	#ifdef HAVE_SPAWN_H
	#include <spawn.h>
	#else
	#include "compat/posix_spawn.h"
	#endif

	/* Allow the OS to define another script env var name */
	#ifndef RC_SVCNAME
	#define RC_SVCNAME "RC_SVCNAME"
	#endif

	#define DEFAULT_PATH "PATH=/usr/bin:/usr/sbin:/bin:/sbin"

	static const char * const if_params[] = {
	"interface",
	"reason",
	"pid",
	"ifcarrier",
	"ifmetric",
	"ifwireless",
	"ifflags",
	"ssid",
	"profile",
	"interface_order",
	NULL
	};

	void
	if_printoptions(void)
	{
	const char * const *p;

	for (p = if_params; *p; p++)
	printf(" - %s\n", *p);
	}

	static int
	exec_script(const struct dhcpcd_ctx ctx, char const argv, char const *env)
	{
	pid_t pid;
	posix_spawnattr_t attr;
	int i;
	#ifdef USE_SIGNALS
	short flags;
	sigset_t defsigs;
	#else
	UNUSED(ctx);
	#endif

	/* posix_spawn is a safe way of executing another image
	* and changing signals back to how they should be. */
	if (posix_spawnattr_init(&attr) == -1)
	return -1;
	#ifdef USE_SIGNALS
	flags = POSIX_SPAWN_SETSIGMASK \| POSIX_SPAWN_SETSIGDEF;
	posix_spawnattr_setflags(&attr, flags);
	sigemptyset(&defsigs);
	for (i = 0; dhcpcd_handlesigs[i]; i++)
	sigaddset(&defsigs, dhcpcd_handlesigs[i]);
	posix_spawnattr_setsigdefault(&attr, &defsigs);
	posix_spawnattr_setsigmask(&attr, &ctx->sigset);
	#endif
	errno = 0;
	i = posix_spawn(&pid, argv[0], NULL, &attr, argv, env);
	if (i) {
	errno = i;
	return -1;
	}
	return pid;
	}

	#ifdef INET
	static char *
	make_var(struct dhcpcd_ctx ctx, const char prefix, const char *var)
	{
	size_t len;
	char *v;

	len = strlen(prefix) + strlen(var) + 2;
	v = malloc(len);
	if (v == NULL) {
	logger(ctx, LOG_ERR, "%s: %m", __func__);
	return NULL;
	}
	snprintf(v, len, "%s_%s", prefix, var);
	return v;
	}


	static int
	append_config(struct dhcpcd_ctx ctx, char *env, size_t len,
	const char prefix, const char const *config)
	{
	size_t i, j, e1;
	char *ne, eq, *nep, p;
	int ret;

	if (config == NULL)
	return 0;

	ne = *env;
	ret = 0;
	for (i = 0; config[i] != NULL; i++) {
	eq = strchr(config[i], '=');
	e1 = (size_t)(eq - config[i] + 1);
	for (j = 0; j < *len; j++) {
	if (strncmp(ne[j] + strlen(prefix) + 1,
	config[i], e1) == 0)
	{
	p = make_var(ctx, prefix, config[i]);
	if (p == NULL) {
	ret = -1;
	break;
	}
	free(ne[j]);
	ne[j] = p;
	break;
	}
	}
	if (j == *len) {
	j++;
	p = make_var(ctx, prefix, config[i]);
	if (p == NULL) {
	ret = -1;
	break;
	}
	nep = realloc(ne, sizeof(char ) (j + 1));
	if (nep == NULL) {
	logger(ctx, LOG_ERR, "%s: %m", __func__);
	free(p);
	ret = -1;
	break;
	}
	ne = nep;
	ne[j - 1] = p;
	*len = j;
	}
	}
	*env = ne;
	return ret;
	}
	#endif

	static ssize_t
	arraytostr(const char const argv, char **s)
	{
	const char const ap;
	char *p;
	size_t len, l;

	if (*argv == NULL)
	return 0;
	len = 0;
	ap = argv;
	while (*ap)
	len += strlen(*ap++) + 1;
	*s = p = malloc(len);
	if (p == NULL)
	return -1;
	ap = argv;
	while (*ap) {
	l = strlen(*ap) + 1;
	memcpy(p, *ap, l);
	p += l;
	ap++;
	}
	return (ssize_t)len;
	}

	static ssize_t
	make_env(const struct interface ifp, const char reason, char ***argv)
	{
	char env, nenv, *p;
	size_t e, elen, l;
	#if defined(INET) \|\| defined(INET6)
	ssize_t n;
	#endif
	const struct if_options *ifo = ifp->options;
	const struct interface *ifp2;
	#ifdef INET
	int dhcp;
	const struct dhcp_state *state;
	#endif
	#ifdef INET6
	const struct dhcp6_state *d6_state;
	int dhcp6, ra;
	#endif

	#ifdef INET
	dhcp = 0;
	state = D_STATE(ifp);
	#endif
	#ifdef INET6
	dhcp6 = ra = 0;
	d6_state = D6_CSTATE(ifp);
	#endif
	if (strcmp(reason, "TEST") == 0) {
	if (1 == 2) {}
	#ifdef INET6
	else if (d6_state && d6_state->new)
	dhcp6 = 1;
	else if (ipv6nd_hasra(ifp))
	ra = 1;
	#endif
	#ifdef INET
	else
	dhcp = 1;
	#endif
	}
	#ifdef INET6
	else if (reason[strlen(reason) - 1] == '6')
	dhcp6 = 1;
	else if (strcmp(reason, "ROUTERADVERT") == 0)
	ra = 1;
	#endif
	else if (strcmp(reason, "PREINIT") == 0 \|\|
	strcmp(reason, "CARRIER") == 0 \|\|
	strcmp(reason, "NOCARRIER") == 0 \|\|
	strcmp(reason, "UNKNOWN") == 0 \|\|
	strcmp(reason, "DEPARTED") == 0 \|\|
	strcmp(reason, "STOPPED") == 0)
	{
	/* This space left intentionally blank */
	}
	#ifdef INET
	else
	dhcp = 1;
	#endif

	/* When dumping the lease, we only want to report interface and
	reason - the other interface variables are meaningless */
	if (ifp->ctx->options & DHCPCD_DUMPLEASE)
	elen = 2;
	else
	elen = 13;

	#define EMALLOC(i, l) if ((env[(i)] = malloc((l))) == NULL) goto eexit;
	/* Make our env + space for profile, wireless and debug */
	env = calloc(1, sizeof(char ) (elen + 3 + 1));
	if (env == NULL)
	goto eexit;
	e = strlen("interface") + strlen(ifp->name) + 2;
	EMALLOC(0, e);
	snprintf(env[0], e, "interface=%s", ifp->name);
	e = strlen("reason") + strlen(reason) + 2;
	EMALLOC(1, e);
	snprintf(env[1], e, "reason=%s", reason);
	if (ifp->ctx->options & DHCPCD_DUMPLEASE)
	goto dumplease;
	e = 20;
	EMALLOC(2, e);
	snprintf(env[2], e, "pid=%d", getpid());
	EMALLOC(3, e);
	snprintf(env[3], e, "ifcarrier=%s",
	ifp->carrier == LINK_UNKNOWN ? "unknown" :
	ifp->carrier == LINK_UP ? "up" : "down");
	EMALLOC(4, e);
	snprintf(env[4], e, "ifmetric=%d", ifp->metric);
	EMALLOC(5, e);
	snprintf(env[5], e, "ifwireless=%d", ifp->wireless);
	EMALLOC(6, e);
	snprintf(env[6], e, "ifflags=%u", ifp->flags);
	EMALLOC(7, e);
	snprintf(env[7], e, "ifmtu=%d", if_getmtu(ifp->name));
	l = e = strlen("interface_order=");
	TAILQ_FOREACH(ifp2, ifp->ctx->ifaces, next) {
	if (!(ifp2->options->options & DHCPCD_PFXDLGONLY))
	e += strlen(ifp2->name) + 1;
	}
	EMALLOC(8, e);
	p = env[8];
	strlcpy(p, "interface_order=", e);
	e -= l;
	p += l;
	TAILQ_FOREACH(ifp2, ifp->ctx->ifaces, next) {
	if (!(ifp2->options->options & DHCPCD_PFXDLGONLY)) {
	l = strlcpy(p, ifp2->name, e);
	p += l;
	e -= l;
	*p++ = ' ';
	e--;
	}
	}
	*--p = '\0';
	if (strcmp(reason, "STOPPED") == 0) {
	env[9] = strdup("if_up=false");
	if (ifo->options & DHCPCD_RELEASE)
	env[10] = strdup("if_down=true");
	else
	env[10] = strdup("if_down=false");
	} else if (strcmp(reason, "TEST") == 0 \|\|
	strcmp(reason, "PREINIT") == 0 \|\|
	strcmp(reason, "CARRIER") == 0 \|\|
	strcmp(reason, "UNKNOWN") == 0)
	{
	env[9] = strdup("if_up=false");
	env[10] = strdup("if_down=false");
	} else if (1 == 2 /* appease ifdefs */
	#ifdef INET
	\|\| (dhcp && state && state->new)
	#endif
	#ifdef INET6
	\|\| (dhcp6 && d6_state && d6_state->new)
	\|\| (ra && ipv6nd_hasra(ifp))
	#endif
	)
	{
	env[9] = strdup("if_up=true");
	env[10] = strdup("if_down=false");
	} else {
	env[9] = strdup("if_up=false");
	env[10] = strdup("if_down=true");
	}
	if (env[9] == NULL \|\| env[10] == NULL)
	goto eexit;
	if (dhcpcd_oneup(ifp->ctx))
	env[11] = strdup("if_oneup=true");
	else
	env[11] = strdup("if_oneup=false");
	if (env[11] == NULL)
	goto eexit;
	if (dhcpcd_ipwaited(ifp->ctx))
	env[12] = strdup("if_ipwaited=true");
	else
	env[12] = strdup("if_ipwaited=false");
	if (env[12] == NULL)
	goto eexit;
	if (ifo->options & DHCPCD_DEBUG) {
	e = strlen("syslog_debug=true") + 1;
	EMALLOC(elen, e);
	snprintf(env[elen++], e, "syslog_debug=true");
	}
	if (*ifp->profile) {
	e = strlen("profile=") + strlen(ifp->profile) + 1;
	EMALLOC(elen, e);
	snprintf(env[elen++], e, "profile=%s", ifp->profile);
	}
	if (ifp->wireless) {
	static const char *pfx = "ifssid=";
	size_t pfx_len;
	ssize_t psl;

	pfx_len = strlen(pfx);
	psl = print_string(NULL, 0, ESCSTRING,
	(const uint8_t *)ifp->ssid, ifp->ssid_len);
	if (psl != -1) {
	EMALLOC(elen, pfx_len + (size_t)psl + 1);
	memcpy(env[elen], pfx, pfx_len);
	print_string(env[elen] + pfx_len, (size_t)psl + 1,
	ESCSTRING,
	(const uint8_t *)ifp->ssid, ifp->ssid_len);
	elen++;
	}
	}
	#ifdef INET
	if (dhcp && state && state->old) {
	n = dhcp_env(NULL, NULL, state->old, ifp);
	if (n == -1)
	goto eexit;
	if (n > 0) {
	nenv = realloc(env, sizeof(char )
	(elen + (size_t)n + 1));
	if (nenv == NULL)
	goto eexit;
	env = nenv;
	n = dhcp_env(env + elen, "old", state->old, ifp);
	if (n == -1)
	goto eexit;
	elen += (size_t)n;
	}
	if (append_config(ifp->ctx, &env, &elen, "old",
	(const char const )ifo->config) == -1)
	goto eexit;
	}
	#endif
	#ifdef INET6
	if (dhcp6 && d6_state && ifo->options & DHCPCD_PFXDLGONLY) {
	nenv = realloc(env, sizeof(char ) (elen + 2));
	if (nenv == NULL)
	goto eexit;
	env = nenv;
	env[elen] = strdup("ifclass=pd");
	if (env[elen] == NULL)
	goto eexit;
	elen++;
	}
	if (dhcp6 && d6_state && d6_state->old) {
	n = dhcp6_env(NULL, NULL, ifp,
	d6_state->old, d6_state->old_len);
	if (n > 0) {
	nenv = realloc(env, sizeof(char )
	(elen + (size_t)n + 1));
	if (nenv == NULL)
	goto eexit;
	env = nenv;
	n = dhcp6_env(env + elen, "old", ifp,
	d6_state->old, d6_state->old_len);
	if (n == -1)
	goto eexit;
	elen += (size_t)n;
	}
	}
	#endif

	dumplease:
	#ifdef INET
	if (dhcp && state && state->new) {
	n = dhcp_env(NULL, NULL, state->new, ifp);
	if (n > 0) {
	nenv = realloc(env, sizeof(char )
	(elen + (size_t)n + 1));
	if (nenv == NULL)
	goto eexit;
	env = nenv;
	n = dhcp_env(env + elen, "new",
	state->new, ifp);
	if (n == -1)
	goto eexit;
	elen += (size_t)n;
	}
	if (append_config(ifp->ctx, &env, &elen, "new",
	(const char const )ifo->config) == -1)
	goto eexit;
	}
	#endif
	#ifdef INET6
	if (dhcp6 && D6_STATE_RUNNING(ifp)) {
	n = dhcp6_env(NULL, NULL, ifp,
	d6_state->new, d6_state->new_len);
	if (n > 0) {
	nenv = realloc(env, sizeof(char )
	(elen + (size_t)n + 1));
	if (nenv == NULL)
	goto eexit;
	env = nenv;
	n = dhcp6_env(env + elen, "new", ifp,
	d6_state->new, d6_state->new_len);
	if (n == -1)
	goto eexit;
	elen += (size_t)n;
	}
	}
	if (ra) {
	n = ipv6nd_env(NULL, NULL, ifp);
	if (n > 0) {
	nenv = realloc(env, sizeof(char )
	(elen + (size_t)n + 1));
	if (nenv == NULL)
	goto eexit;
	env = nenv;
	n = ipv6nd_env(env + elen, NULL, ifp);
	if (n == -1)
	goto eexit;
	elen += (size_t)n;
	}
	}
	#endif

	/* Add our base environment */
	if (ifo->environ) {
	e = 0;
	while (ifo->environ[e++])
	;
	nenv = realloc(env, sizeof(char ) (elen + e + 1));
	if (nenv == NULL)
	goto eexit;
	env = nenv;
	e = 0;
	while (ifo->environ[e]) {
	env[elen + e] = strdup(ifo->environ[e]);
	if (env[elen + e] == NULL)
	goto eexit;
	e++;
	}
	elen += e;
	}
	env[elen] = NULL;

	*argv = env;
	return (ssize_t)elen;

	eexit:
	logger(ifp->ctx, LOG_ERR, "%s: %m", __func__);
	if (env) {
	nenv = env;
	while (*nenv)
	free(*nenv++);
	free(env);
	}
	return -1;
	}

	static int
	send_interface1(struct fd_list fd, const struct interface iface,
	const char *reason)
	{
	char env, ep, *s;
	size_t elen;
	int retval;

	if (make_env(iface, reason, &env) == -1)
	return -1;
	s = NULL;
	elen = (size_t)arraytostr((const char const )env, &s);
	if ((ssize_t)elen == -1) {
	free(s);
	return -1;
	}
	retval = control_queue(fd, s, elen, 1);
	ep = env;
	while (*ep)
	free(*ep++);
	free(env);
	return retval;
	}

	int
	send_interface(struct fd_list fd, const struct interface ifp)
	{
	const char *reason;
	int retval = 0;
	#ifdef INET
	const struct dhcp_state *d;
	#endif
	#ifdef INET6
	const struct dhcp6_state *d6;
	#endif

	switch (ifp->carrier) {
	case LINK_UP:
	reason = "CARRIER";
	break;
	case LINK_DOWN:
	reason = "NOCARRIER";
	break;
	default:
	reason = "UNKNOWN";
	break;
	}
	if (send_interface1(fd, ifp, reason) == -1)
	retval = -1;
	#ifdef INET
	if (D_STATE_RUNNING(ifp)) {
	d = D_CSTATE(ifp);
	if (send_interface1(fd, ifp, d->reason) == -1)
	retval = -1;
	}
	#endif

	#ifdef INET6
	if (RS_STATE_RUNNING(ifp)) {
	if (send_interface1(fd, ifp, "ROUTERADVERT") == -1)
	retval = -1;
	}
	if (D6_STATE_RUNNING(ifp)) {
	d6 = D6_CSTATE(ifp);
	if (send_interface1(fd, ifp, d6->reason) == -1)
	retval = -1;
	}
	#endif

	return retval;
	}

	int
	script_runreason(const struct interface ifp, const char reason)
	{
	char *argv[2];
	char env = NULL, ep;
	char svcname, path, *bigenv;
	size_t e, elen = 0;
	pid_t pid;
	int status = 0;
	struct fd_list *fd;

	if (ifp->options->script &&
	(ifp->options->script[0] == '\0' \|\|
	strcmp(ifp->options->script, "/dev/null") == 0))
	return 0;

	argv[0] = ifp->options->script ? ifp->options->script : UNCONST(SCRIPT);
	argv[1] = NULL;
	logger(ifp->ctx, LOG_DEBUG, "%s: executing `%s' %s",
	ifp->name, argv[0], reason);

	/* Make our env */
	elen = (size_t)make_env(ifp, reason, &env);
	if (elen == (size_t)-1) {
	logger(ifp->ctx, LOG_ERR, "%s: make_env: %m", ifp->name);
	return -1;
	}
	/* Resize for PATH and RC_SVCNAME */
	svcname = getenv(RC_SVCNAME);
	ep = realloc(env, sizeof(char ) (elen + 2 + (svcname ? 1 : 0)));
	if (ep == NULL) {
	elen = 0;
	goto out;
	}
	env = ep;
	/* Add path to it */
	path = getenv("PATH");
	if (path) {
	e = strlen("PATH") + strlen(path) + 2;
	env[elen] = malloc(e);
	if (env[elen] == NULL) {
	elen = 0;
	goto out;
	}
	snprintf(env[elen], e, "PATH=%s", path);
	} else {
	env[elen] = strdup(DEFAULT_PATH);
	if (env[elen] == NULL) {
	elen = 0;
	goto out;
	}
	}
	if (svcname) {
	e = strlen(RC_SVCNAME) + strlen(svcname) + 2;
	env[++elen] = malloc(e);
	if (env[elen] == NULL) {
	elen = 0;
	goto out;
	}
	snprintf(env[elen], e, "%s=%s", RC_SVCNAME, svcname);
	}
	env[++elen] = NULL;

	pid = exec_script(ifp->ctx, argv, env);
	if (pid == -1)
	logger(ifp->ctx, LOG_ERR, "%s: %s: %m", __func__, argv[0]);
	else if (pid != 0) {
	/* Wait for the script to finish */
	while (waitpid(pid, &status, 0) == -1) {
	if (errno != EINTR) {
	logger(ifp->ctx, LOG_ERR, "waitpid: %m");
	status = 0;
	break;
	}
	}
	if (WIFEXITED(status)) {
	if (WEXITSTATUS(status))
	logger(ifp->ctx, LOG_ERR,
	"%s: %s: WEXITSTATUS %d",
	__func__, argv[0], WEXITSTATUS(status));
	} else if (WIFSIGNALED(status))
	logger(ifp->ctx, LOG_ERR, "%s: %s: %s",
	__func__, argv[0], strsignal(WTERMSIG(status)));
	}

	/* Send to our listeners */
	bigenv = NULL;
	status = 0;
	TAILQ_FOREACH(fd, &ifp->ctx->control_fds, next) {
	if (!(fd->flags & FD_LISTEN))
	continue;
	if (bigenv == NULL) {
	elen = (size_t)arraytostr((const char const )env,
	&bigenv);
	if ((ssize_t)elen == -1) {
	logger(ifp->ctx, LOG_ERR, "%s: arraytostr: %m",
	ifp->name);
	break;
	}
	}
	if (control_queue(fd, bigenv, elen, 1) == -1)
	logger(ifp->ctx, LOG_ERR,
	"%s: control_queue: %m", __func__);
	else
	status = 1;
	}
	if (!status)
	free(bigenv);

	out:
	/* Cleanup */
	ep = env;
	while (*ep)
	free(*ep++);
	free(env);
	if (elen == 0)
	return -1;
	return WEXITSTATUS(status);
	}