mirror of
https://github.com/sheumann/hush.git
synced 2024-08-14 11:28:58 +00:00
225 lines
5.7 KiB
C
225 lines
5.7 KiB
C
/* vi: set sw=4 ts=4: */
|
|
/* script.c
|
|
*
|
|
* Functions to call the DHCP client notification scripts
|
|
*
|
|
* Russ Dill <Russ.Dill@asu.edu> July 2001
|
|
*
|
|
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
|
|
*/
|
|
|
|
#include "common.h"
|
|
#include "dhcpd.h"
|
|
#include "dhcpc.h"
|
|
#include "options.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,
|
|
#if ENABLE_FEATURE_RFC3397
|
|
[OPTION_STR1035] = 1,
|
|
#endif
|
|
[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, const char *pre, const 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;
|
|
}
|
|
|
|
|
|
/* Allocate and fill with the text of option 'option'. */
|
|
static char *alloc_fill_opts(uint8_t *option, const struct dhcp_option *type_p)
|
|
{
|
|
int len, type, optlen;
|
|
uint16_t val_u16;
|
|
int16_t val_s16;
|
|
uint32_t val_u32;
|
|
int32_t val_s32;
|
|
char *dest, *ret;
|
|
|
|
len = option[OPT_LEN - 2];
|
|
type = type_p->flags & TYPE_MASK;
|
|
optlen = option_lengths[type];
|
|
|
|
dest = ret = xmalloc(upper_length(len, type) + strlen(type_p->name) + 2);
|
|
dest += sprintf(ret, "%s=", type_p->name);
|
|
|
|
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 ret; /* Short circuit this case */
|
|
#if ENABLE_FEATURE_RFC3397
|
|
case OPTION_STR1035:
|
|
/* unpack option into dest; use ret for prefix (i.e., "optname=") */
|
|
dest = dname_dec(option, len, ret);
|
|
free(ret);
|
|
return dest;
|
|
#endif
|
|
}
|
|
option += optlen;
|
|
len -= optlen;
|
|
if (len <= 0) break;
|
|
dest += sprintf(dest, " ");
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
|
|
/* 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 = xzalloc(sizeof(char *) * (num_options + 5));
|
|
j = 0;
|
|
envp[j++] = xasprintf("interface=%s", client_config.interface);
|
|
envp[j++] = xasprintf("PATH=%s",
|
|
getenv("PATH") ? : "/bin:/usr/bin:/sbin:/usr/sbin");
|
|
envp[j++] = xasprintf("HOME=%s", 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++) {
|
|
temp = get_option(packet, dhcp_options[i].code);
|
|
if (!temp)
|
|
continue;
|
|
envp[j++] = alloc_fill_opts(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);
|
|
envp[j++] = xasprintf("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';
|
|
envp[j++] = xasprintf("boot_file=%s", packet->file);
|
|
}
|
|
if (!(over & SNAME_FIELD) && packet->sname[0]) {
|
|
/* watch out for invalid packets */
|
|
packet->sname[sizeof(packet->sname) - 1] = '\0';
|
|
envp[j++] = xasprintf("sname=%s", packet->sname);
|
|
}
|
|
return envp;
|
|
}
|
|
|
|
|
|
/* Call a script with a par file and env vars */
|
|
void udhcp_run_script(struct dhcpMessage *packet, const char *name)
|
|
{
|
|
int pid;
|
|
char **envp, **curr;
|
|
|
|
if (client_config.script == NULL)
|
|
return;
|
|
|
|
DEBUG("vfork'ing 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);
|
|
bb_perror_msg("script %s failed", client_config.script);
|
|
exit(1);
|
|
}
|
|
}
|