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/**
* Copyright (C) 2012-2013 Steven Barth <steven@midlink.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License v2 as published by
* the Free Software Foundation.
*
* 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.
*
*/
#include <stdio.h>
#include <resolv.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <signal.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include "odhcp6c.h"
static const char hexdigits[] = "0123456789abcdef";
static const int8_t hexvals[] = {
-1, -1, -1, -1, -1, -1, -1, -1, -1, -2, -2, -1, -1, -2, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1,
-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
};
static char *argv[4] = {NULL, NULL, NULL, NULL};
static volatile char *delayed_call = NULL;
int script_init(const char *path, const char *ifname)
{
argv[0] = (char*)path;
argv[1] = (char*)ifname;
return 0;
}
ssize_t script_unhexlify(uint8_t *dst, size_t len, const char *src)
{
size_t c;
for (c = 0; c < len && src[0] && src[1]; ++c) {
int8_t x = (int8_t)*src++;
int8_t y = (int8_t)*src++;
if (x < 0 || (x = hexvals[x]) < 0
|| y < 0 || (y = hexvals[y]) < 0)
return -1;
dst[c] = x << 4 | y;
while (((int8_t)*src) < 0 ||
(*src && hexvals[(uint8_t)*src] < 0))
src++;
}
return c;
}
static void script_hexlify(char *dst, const uint8_t *src, size_t len) {
for (size_t i = 0; i < len; ++i) {
*dst++ = hexdigits[src[i] >> 4];
*dst++ = hexdigits[src[i] & 0x0f];
}
*dst = 0;
}
static void ipv6_to_env(const char *name,
const struct in6_addr *addr, size_t cnt)
{
size_t buf_len = strlen(name);
char *buf = realloc(NULL, cnt * INET6_ADDRSTRLEN + buf_len + 2);
memcpy(buf, name, buf_len);
buf[buf_len++] = '=';
for (size_t i = 0; i < cnt; ++i) {
inet_ntop(AF_INET6, &addr[i], &buf[buf_len], INET6_ADDRSTRLEN);
buf_len += strlen(&buf[buf_len]);
buf[buf_len++] = ' ';
}
buf[buf_len - 1] = '\0';
putenv(buf);
}
static void fqdn_to_env(const char *name, const uint8_t *fqdn, size_t len)
{
size_t buf_len = strlen(name);
const uint8_t *fqdn_end = fqdn + len;
char *buf = realloc(NULL, len + buf_len + 2);
memcpy(buf, name, buf_len);
buf[buf_len++] = '=';
int l = 1;
while (l > 0 && fqdn < fqdn_end) {
l = dn_expand(fqdn, &fqdn[len], fqdn, &buf[buf_len], len);
fqdn += l;
buf_len += strlen(&buf[buf_len]);
buf[buf_len++] = ' ';
}
buf[buf_len - 1] = '\0';
putenv(buf);
}
static void bin_to_env(uint8_t *opts, size_t len)
{
uint8_t *oend = opts + len, *odata;
uint16_t otype, olen;
dhcpv6_for_each_option(opts, oend, otype, olen, odata) {
char *buf = realloc(NULL, 14 + (olen * 2));
size_t buf_len = 0;
snprintf(buf, 14, "OPTION_%hu=", otype);
buf_len += strlen(buf);
script_hexlify(&buf[buf_len], odata, olen);
putenv(buf);
}
}
enum entry_type {
ENTRY_ADDRESS,
ENTRY_HOST,
ENTRY_ROUTE,
ENTRY_PREFIX
};
static void entry_to_env(const char *name, const void *data, size_t len, enum entry_type type)
{
size_t buf_len = strlen(name);
const struct odhcp6c_entry *e = data;
char *buf = realloc(NULL, buf_len + 2 + (len / sizeof(*e)) * 144);
memcpy(buf, name, buf_len);
buf[buf_len++] = '=';
for (size_t i = 0; i < len / sizeof(*e); ++i) {
inet_ntop(AF_INET6, &e[i].target, &buf[buf_len], INET6_ADDRSTRLEN);
buf_len += strlen(&buf[buf_len]);
if (type != ENTRY_HOST) {
buf_len += snprintf(&buf[buf_len], 6, "/%hhu", e[i].length);
if (type == ENTRY_ROUTE) {
buf[buf_len++] = ',';
if (!IN6_IS_ADDR_UNSPECIFIED(&e[i].router)) {
inet_ntop(AF_INET6, &e[i].router, &buf[buf_len], INET6_ADDRSTRLEN);
buf_len += strlen(&buf[buf_len]);
}
buf_len += snprintf(&buf[buf_len], 24, ",%u", e[i].valid);
buf_len += snprintf(&buf[buf_len], 12, ",%u", e[i].priority);
} else {
buf_len += snprintf(&buf[buf_len], 24, ",%u,%u", e[i].preferred, e[i].valid);
}
if (type == ENTRY_PREFIX && e[i].priority) {
// priority and router are abused for prefix exclusion
buf[buf_len++] = ',';
inet_ntop(AF_INET6, &e[i].router, &buf[buf_len], INET6_ADDRSTRLEN);
buf_len += strlen(&buf[buf_len]);
buf_len += snprintf(&buf[buf_len], 24, "/%u", e[i].priority);
}
}
buf[buf_len++] = ' ';
}
buf[buf_len - 1] = '\0';
putenv(buf);
}
static void script_call_delayed(int signal __attribute__((unused)))
{
if (delayed_call)
script_call((char*)delayed_call);
}
void script_delay_call(const char *status, int timeout)
{
if (!delayed_call) {
delayed_call = strdup(status);
signal(SIGALRM, script_call_delayed);
alarm(timeout);
}
}
void script_call(const char *status)
{
size_t dns_len, search_len, custom_len, sntp_ip_len, sntp_dns_len;
size_t sip_ip_len, sip_fqdn_len;
odhcp6c_expire();
if (delayed_call)
alarm(0);
struct in6_addr *dns = odhcp6c_get_state(STATE_DNS, &dns_len);
uint8_t *search = odhcp6c_get_state(STATE_SEARCH, &search_len);
uint8_t *custom = odhcp6c_get_state(STATE_CUSTOM_OPTS, &custom_len);
struct in6_addr *sntp = odhcp6c_get_state(STATE_SNTP_IP, &sntp_ip_len);
uint8_t *sntp_dns = odhcp6c_get_state(STATE_SNTP_FQDN, &sntp_dns_len);
struct in6_addr *sip = odhcp6c_get_state(STATE_SIP_IP, &sip_ip_len);
uint8_t *sip_fqdn = odhcp6c_get_state(STATE_SIP_FQDN, &sip_fqdn_len);
size_t prefix_len, address_len, ra_pref_len, ra_route_len, ra_dns_len;
uint8_t *prefix = odhcp6c_get_state(STATE_IA_PD, &prefix_len);
uint8_t *address = odhcp6c_get_state(STATE_IA_NA, &address_len);
uint8_t *ra_pref = odhcp6c_get_state(STATE_RA_PREFIX, &ra_pref_len);
uint8_t *ra_route = odhcp6c_get_state(STATE_RA_ROUTE, &ra_route_len);
uint8_t *ra_dns = odhcp6c_get_state(STATE_RA_DNS, &ra_dns_len);
// Don't set environment before forking, because env is leaky.
if (fork() == 0) {
ipv6_to_env("RDNSS", dns, dns_len / sizeof(*dns));
ipv6_to_env("SNTP_IP", sntp, sntp_ip_len / sizeof(*sntp));
ipv6_to_env("SIP_IP", sip, sip_ip_len / sizeof(*sip));
fqdn_to_env("DOMAINS", search, search_len);
fqdn_to_env("SNTP_FQDN", sntp_dns, sntp_dns_len);
fqdn_to_env("SIP_DOMAIN", sip_fqdn, sip_fqdn_len);
bin_to_env(custom, custom_len);
entry_to_env("PREFIXES", prefix, prefix_len, ENTRY_PREFIX);
entry_to_env("ADDRESSES", address, address_len, ENTRY_ADDRESS);
entry_to_env("RA_ADDRESSES", ra_pref, ra_pref_len, ENTRY_ADDRESS);
entry_to_env("RA_ROUTES", ra_route, ra_route_len, ENTRY_ROUTE);
entry_to_env("RA_DNS", ra_dns, ra_dns_len, ENTRY_HOST);
argv[2] = (char*)status;
execv(argv[0], argv);
_exit(128);
}
// Delete lost prefixes and user opts
odhcp6c_clear_state(STATE_CUSTOM_OPTS);
}
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