diff options
Diffstat (limited to 'src/script.c')
| -rw-r--r-- | src/script.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/src/script.c b/src/script.c new file mode 100644 index 0000000..2a34ea0 --- /dev/null +++ b/src/script.c @@ -0,0 +1,184 @@ +/** + * Copyright (C) 2012 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 <unistd.h> +#include <arpa/inet.h> +#include <netinet/in.h> + +#include "odhcp6c.h" + +static const char hexdigits[] = "0123456789abcdef"; +static const char 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}; + + +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 (*src < 0 || (*src && hexvals[(uint8_t)*src] < 0)) + src++; + } + + return c; +} + + +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); + } +} + + +static void prefix_to_env(const char *name, const uint8_t *fqdn, size_t len) +{ + size_t buf_len = strlen(name); + struct dhcpv6_ia_prefix *p = NULL; + char *buf = realloc(NULL, buf_len + 2 + + (len / sizeof(*p)) * (INET6_ADDRSTRLEN + 32)); + memcpy(buf, name, buf_len); + buf[buf_len++] = '='; + + uint16_t otype, olen; + uint8_t *odata; + dhcpv6_for_each_option(fqdn, &fqdn[len], otype, olen, odata) { + if (otype != DHCPV6_OPT_IA_PREFIX || olen + 4U < sizeof(*p)) + continue; + + p = (struct dhcpv6_ia_prefix*)&odata[-4]; + inet_ntop(AF_INET6, &p->addr, &buf[buf_len], INET6_ADDRSTRLEN); + buf_len += strlen(&buf[buf_len]); + buf_len += snprintf(&buf[buf_len], 32, "/%hhu,%u,%u ", + p->prefix, ntohl(p->preferred), + ntohl(p->valid)); + } + buf[buf_len - 1] = '\0'; + putenv(buf); +} + + +void script_call(const char *status) +{ + size_t dns_len, search_len, custom_len; + 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); + + size_t prefix_len, lost_pd_len; + uint8_t *prefix = odhcp6c_get_state(STATE_IA_PD, &prefix_len); + uint8_t *lost_pd = odhcp6c_get_state(STATE_IA_PD_LOST, &lost_pd_len); + + // Don't set environment before forking, because env is leaky. + if (fork() == 0) { + ipv6_to_env("RDNSS", dns, dns_len / sizeof(*dns)); + fqdn_to_env("DOMAINS", search, search_len); + bin_to_env(custom, custom_len); + prefix_to_env("PREFIXES", prefix, prefix_len); + prefix_to_env("PREFIXES_LOST", lost_pd, lost_pd_len); + + argv[2] = (char*)status; + execv(argv[0], argv); + _exit(128); + } + + // Delete lost prefixes and user opts + odhcp6c_clear_state(STATE_IA_PD_LOST); + odhcp6c_clear_state(STATE_CUSTOM_OPTS); +} |