/* script.c * * Functions to call the DHCP client notification scripts * * Russ Dill <Russ.Dill@asu.edu> July 2001 * * 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 * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */#include <string.h>#include <unistd.h>#include <stdio.h>#include <stdlib.h>#include <sys/socket.h>#include <netinet/in.h>#include <arpa/inet.h>#include <sys/types.h>#include <sys/wait.h>#include "options.h"#include "dhcpd.h"#include "dhcpc.h"#include "common.h"/* get a rough idea of how long an option will be (rounding up...) */static const int max_option_length[] = {	[OPTION_IP] =		sizeof("255.255.255.255 "),	[OPTION_IP_PAIR] =	sizeof("255.255.255.255 ") * 2,	[OPTION_STRING] =	1,	[OPTION_BOOLEAN] =	sizeof("yes "),	[OPTION_U8] =		sizeof("255 "),	[OPTION_U16] =		sizeof("65535 "),	[OPTION_S16] =		sizeof("-32768 "),	[OPTION_U32] =		sizeof("4294967295 "),	[OPTION_S32] =		sizeof("-2147483684 "),};static inline int upper_length(int length, int opt_index){	return max_option_length[opt_index] *		(length / option_lengths[opt_index]);}static int sprintip(char *dest, char *pre, uint8_t *ip){	return sprintf(dest, "%s%d.%d.%d.%d", pre, ip[0], ip[1], ip[2], ip[3]);}/* really simple implementation, just count the bits */static int mton(struct in_addr *mask){	int i;	unsigned long bits = ntohl(mask->s_addr);	/* too bad one can't check the carry bit, etc in c bit	 * shifting */	for (i = 0; i < 32 && !((bits >> i) & 1); i++);	return 32 - i;}/* Fill dest with the text of option 'option'. */static void fill_options(char *dest, uint8_t *option, struct dhcp_option *type_p){	int type, optlen;	uint16_t val_u16;	int16_t val_s16;	uint32_t val_u32;	int32_t val_s32;	int len = option[OPT_LEN - 2];	dest += sprintf(dest, "%s=", type_p->name);	type = type_p->flags & TYPE_MASK;	optlen = option_lengths[type];	for(;;) {		switch (type) {		case OPTION_IP_PAIR:			dest += sprintip(dest, "", option);			*(dest++) = '/';			option += 4;			optlen = 4;		case OPTION_IP:	/* Works regardless of host byte order. */			dest += sprintip(dest, "", option); 			break;		case OPTION_BOOLEAN:			dest += sprintf(dest, *option ? "yes" : "no");			break;		case OPTION_U8:			dest += sprintf(dest, "%u", *option);			break;		case OPTION_U16:			memcpy(&val_u16, option, 2);			dest += sprintf(dest, "%u", ntohs(val_u16));			break;		case OPTION_S16:			memcpy(&val_s16, option, 2);			dest += sprintf(dest, "%d", ntohs(val_s16));			break;		case OPTION_U32:			memcpy(&val_u32, option, 4);			dest += sprintf(dest, "%lu", (unsigned long) ntohl(val_u32));			break;		case OPTION_S32:			memcpy(&val_s32, option, 4);			dest += sprintf(dest, "%ld", (long) ntohl(val_s32));			break;		case OPTION_STRING:			memcpy(dest, option, len);			dest[len] = '\0';			return;	 /* Short circuit this case */		}		option += optlen;		len -= optlen;		if (len <= 0) break;		dest += sprintf(dest, " ");	}}/* put all the parameters into an environment */static char **fill_envp(struct dhcpMessage *packet){	int num_options = 0;	int i, j;	char **envp;	uint8_t *temp;	struct in_addr subnet;	char over = 0;	if (packet == NULL)		num_options = 0;	else {		for (i = 0; dhcp_options[i].code; i++)			if (get_option(packet, dhcp_options[i].code)) {				num_options++;				if (dhcp_options[i].code == DHCP_SUBNET)					num_options++; /* for mton */			}		if (packet->siaddr) num_options++;		if ((temp = get_option(packet, DHCP_OPTION_OVER)))			over = *temp;		if (!(over & FILE_FIELD) && packet->file[0]) num_options++;		if (!(over & SNAME_FIELD) && packet->sname[0]) num_options++;	}	envp = xcalloc(sizeof(char *), num_options + 5);	j = 0;	asprintf(&envp[j++], "interface=%s", client_config.interface);	asprintf(&envp[j++], "%s=%s", "PATH",		getenv("PATH") ? : "/bin:/usr/bin:/sbin:/usr/sbin");	asprintf(&envp[j++], "%s=%s", "HOME", getenv("HOME") ? : "/");	if (packet == NULL) return envp;	envp[j] = xmalloc(sizeof("ip=255.255.255.255"));	sprintip(envp[j++], "ip=", (uint8_t *) &packet->yiaddr);	for (i = 0; dhcp_options[i].code; i++) {		if (!(temp = get_option(packet, dhcp_options[i].code)))			continue;		envp[j] = xmalloc(upper_length(temp[OPT_LEN - 2],			dhcp_options[i].flags & TYPE_MASK) + strlen(dhcp_options[i].name) + 2);		fill_options(envp[j++], temp, &dhcp_options[i]);		/* Fill in a subnet bits option for things like /24 */		if (dhcp_options[i].code == DHCP_SUBNET) {			memcpy(&subnet, temp, 4);			asprintf(&envp[j++], "mask=%d", mton(&subnet));		}	}	if (packet->siaddr) {		envp[j] = xmalloc(sizeof("siaddr=255.255.255.255"));		sprintip(envp[j++], "siaddr=", (uint8_t *) &packet->siaddr);	}	if (!(over & FILE_FIELD) && packet->file[0]) {		/* watch out for invalid packets */		packet->file[sizeof(packet->file) - 1] = '\0';		asprintf(&envp[j++], "boot_file=%s", packet->file);	}	if (!(over & SNAME_FIELD) && packet->sname[0]) {		/* watch out for invalid packets */		packet->sname[sizeof(packet->sname) - 1] = '\0';		asprintf(&envp[j++], "sname=%s", packet->sname);	}	return envp;}/* Call a script with a par file and env vars */void run_script(struct dhcpMessage *packet, const char *name){	int pid;	char **envp, **curr;	if (client_config.script == NULL)		return;	DEBUG(LOG_INFO, "vforking and execle'ing %s", client_config.script);	envp = fill_envp(packet);	/* call script */	pid = vfork();	if (pid) {		waitpid(pid, NULL, 0);		for (curr = envp; *curr; curr++) free(*curr);		free(envp);		return;	} else if (pid == 0) {		/* close fd's? */		/* exec script */		execle(client_config.script, client_config.script,		       name, NULL, envp);		LOG(LOG_ERR, "script %s failed: %m", client_config.script);		exit(1);	}}