diff options
Diffstat (limited to 'src/libsystemd-network/dhcp6-option.c')
| -rw-r--r-- | src/libsystemd-network/dhcp6-option.c | 414 |
1 files changed, 414 insertions, 0 deletions
diff --git a/src/libsystemd-network/dhcp6-option.c b/src/libsystemd-network/dhcp6-option.c new file mode 100644 index 0000000000..91d7f8a7da --- /dev/null +++ b/src/libsystemd-network/dhcp6-option.c @@ -0,0 +1,414 @@ +/*** + This file is part of systemd. + + Copyright (C) 2014-2015 Intel Corporation. All rights reserved. + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <errno.h> +#include <netinet/in.h> +#include <string.h> + +#include <systemd/sd-dhcp6-client.h> + +#include "alloc-util.h" +#include "dhcp6-internal.h" +#include "dhcp6-protocol.h" +#include "dns-domain.h" +#include "sparse-endian.h" +#include "strv.h" +#include "unaligned.h" +#include "util.h" + +#define DHCP6_OPTION_IA_NA_LEN 12 +#define DHCP6_OPTION_IA_TA_LEN 4 + +typedef struct DHCP6Option { + be16_t code; + be16_t len; + uint8_t data[]; +} _packed_ DHCP6Option; + +static int option_append_hdr(uint8_t **buf, size_t *buflen, uint16_t optcode, + size_t optlen) { + DHCP6Option *option = (DHCP6Option*) *buf; + + assert_return(buf, -EINVAL); + assert_return(*buf, -EINVAL); + assert_return(buflen, -EINVAL); + + if (optlen > 0xffff || *buflen < optlen + sizeof(DHCP6Option)) + return -ENOBUFS; + + option->code = htobe16(optcode); + option->len = htobe16(optlen); + + *buf += sizeof(DHCP6Option); + *buflen -= sizeof(DHCP6Option); + + return 0; +} + +int dhcp6_option_append(uint8_t **buf, size_t *buflen, uint16_t code, + size_t optlen, const void *optval) { + int r; + + assert_return(optval || optlen == 0, -EINVAL); + + r = option_append_hdr(buf, buflen, code, optlen); + if (r < 0) + return r; + + if (optval) + memcpy(*buf, optval, optlen); + + *buf += optlen; + *buflen -= optlen; + + return 0; +} + +int dhcp6_option_append_ia(uint8_t **buf, size_t *buflen, DHCP6IA *ia) { + uint16_t len; + uint8_t *ia_hdr; + size_t ia_buflen, ia_addrlen = 0; + DHCP6Address *addr; + int r; + + assert_return(buf && *buf && buflen && ia, -EINVAL); + + switch (ia->type) { + case SD_DHCP6_OPTION_IA_NA: + len = DHCP6_OPTION_IA_NA_LEN; + break; + + case SD_DHCP6_OPTION_IA_TA: + len = DHCP6_OPTION_IA_TA_LEN; + break; + + default: + return -EINVAL; + } + + if (*buflen < len) + return -ENOBUFS; + + ia_hdr = *buf; + ia_buflen = *buflen; + + *buf += sizeof(DHCP6Option); + *buflen -= sizeof(DHCP6Option); + + memcpy(*buf, &ia->id, len); + + *buf += len; + *buflen -= len; + + LIST_FOREACH(addresses, addr, ia->addresses) { + r = option_append_hdr(buf, buflen, SD_DHCP6_OPTION_IAADDR, + sizeof(addr->iaaddr)); + if (r < 0) + return r; + + memcpy(*buf, &addr->iaaddr, sizeof(addr->iaaddr)); + + *buf += sizeof(addr->iaaddr); + *buflen -= sizeof(addr->iaaddr); + + ia_addrlen += sizeof(DHCP6Option) + sizeof(addr->iaaddr); + } + + r = option_append_hdr(&ia_hdr, &ia_buflen, ia->type, len + ia_addrlen); + if (r < 0) + return r; + + return 0; +} + + +static int option_parse_hdr(uint8_t **buf, size_t *buflen, uint16_t *optcode, size_t *optlen) { + DHCP6Option *option = (DHCP6Option*) *buf; + uint16_t len; + + assert_return(buf, -EINVAL); + assert_return(optcode, -EINVAL); + assert_return(optlen, -EINVAL); + + if (*buflen < sizeof(DHCP6Option)) + return -ENOMSG; + + len = be16toh(option->len); + + if (len > *buflen) + return -ENOMSG; + + *optcode = be16toh(option->code); + *optlen = len; + + *buf += 4; + *buflen -= 4; + + return 0; +} + +int dhcp6_option_parse(uint8_t **buf, size_t *buflen, uint16_t *optcode, + size_t *optlen, uint8_t **optvalue) { + int r; + + assert_return(buf && buflen && optcode && optlen && optvalue, -EINVAL); + + r = option_parse_hdr(buf, buflen, optcode, optlen); + if (r < 0) + return r; + + if (*optlen > *buflen) + return -ENOBUFS; + + *optvalue = *buf; + *buflen -= *optlen; + *buf += *optlen; + + return 0; +} + +int dhcp6_option_parse_ia(uint8_t **buf, size_t *buflen, uint16_t iatype, + DHCP6IA *ia) { + int r; + uint16_t opt, status; + size_t optlen; + size_t iaaddr_offset; + DHCP6Address *addr; + uint32_t lt_t1, lt_t2, lt_valid, lt_pref, lt_min = ~0; + + assert_return(ia, -EINVAL); + assert_return(!ia->addresses, -EINVAL); + + switch (iatype) { + case SD_DHCP6_OPTION_IA_NA: + + if (*buflen < DHCP6_OPTION_IA_NA_LEN + sizeof(DHCP6Option) + + sizeof(addr->iaaddr)) { + r = -ENOBUFS; + goto error; + } + + iaaddr_offset = DHCP6_OPTION_IA_NA_LEN; + memcpy(&ia->id, *buf, iaaddr_offset); + + lt_t1 = be32toh(ia->lifetime_t1); + lt_t2 = be32toh(ia->lifetime_t2); + + if (lt_t1 && lt_t2 && lt_t1 > lt_t2) { + log_dhcp6_client(client, "IA T1 %ds > T2 %ds", + lt_t1, lt_t2); + r = -EINVAL; + goto error; + } + + break; + + case SD_DHCP6_OPTION_IA_TA: + if (*buflen < DHCP6_OPTION_IA_TA_LEN + sizeof(DHCP6Option) + + sizeof(addr->iaaddr)) { + r = -ENOBUFS; + goto error; + } + + iaaddr_offset = DHCP6_OPTION_IA_TA_LEN; + memcpy(&ia->id, *buf, iaaddr_offset); + + ia->lifetime_t1 = 0; + ia->lifetime_t2 = 0; + + break; + + default: + r = -ENOMSG; + goto error; + } + + ia->type = iatype; + + *buflen -= iaaddr_offset; + *buf += iaaddr_offset; + + while ((r = option_parse_hdr(buf, buflen, &opt, &optlen)) >= 0) { + + switch (opt) { + case SD_DHCP6_OPTION_IAADDR: + + addr = new0(DHCP6Address, 1); + if (!addr) { + r = -ENOMEM; + goto error; + } + + LIST_INIT(addresses, addr); + + memcpy(&addr->iaaddr, *buf, sizeof(addr->iaaddr)); + + lt_valid = be32toh(addr->iaaddr.lifetime_valid); + lt_pref = be32toh(addr->iaaddr.lifetime_valid); + + if (!lt_valid || lt_pref > lt_valid) { + log_dhcp6_client(client, "IA preferred %ds > valid %ds", + lt_pref, lt_valid); + free(addr); + } else { + LIST_PREPEND(addresses, ia->addresses, addr); + if (lt_valid < lt_min) + lt_min = lt_valid; + } + + break; + + case SD_DHCP6_OPTION_STATUS_CODE: + if (optlen < sizeof(status)) + break; + + status = (*buf)[0] << 8 | (*buf)[1]; + if (status) { + log_dhcp6_client(client, "IA status %d", + status); + r = -EINVAL; + goto error; + } + + break; + + default: + log_dhcp6_client(client, "Unknown IA option %d", opt); + break; + } + + *buflen -= optlen; + *buf += optlen; + } + + if (r == -ENOMSG) + r = 0; + + if (!ia->lifetime_t1 && !ia->lifetime_t2) { + lt_t1 = lt_min / 2; + lt_t2 = lt_min / 10 * 8; + ia->lifetime_t1 = htobe32(lt_t1); + ia->lifetime_t2 = htobe32(lt_t2); + + log_dhcp6_client(client, "Computed IA T1 %ds and T2 %ds as both were zero", + lt_t1, lt_t2); + } + + if (*buflen) + r = -ENOMSG; + +error: + *buf += *buflen; + *buflen = 0; + + return r; +} + +int dhcp6_option_parse_ip6addrs(uint8_t *optval, uint16_t optlen, + struct in6_addr **addrs, size_t count, + size_t *allocated) { + + if (optlen == 0 || optlen % sizeof(struct in6_addr) != 0) + return -EINVAL; + + if (!GREEDY_REALLOC(*addrs, *allocated, + count * sizeof(struct in6_addr) + optlen)) + return -ENOMEM; + + memcpy(*addrs + count, optval, optlen); + + count += optlen / sizeof(struct in6_addr); + + return count; +} + +int dhcp6_option_parse_domainname(const uint8_t *optval, uint16_t optlen, char ***str_arr) { + size_t pos = 0, idx = 0; + _cleanup_free_ char **names = NULL; + int r; + + assert_return(optlen > 1, -ENODATA); + assert_return(optval[optlen - 1] == '\0', -EINVAL); + + while (pos < optlen) { + _cleanup_free_ char *ret = NULL; + size_t n = 0, allocated = 0; + bool first = true; + + for (;;) { + uint8_t c; + + c = optval[pos++]; + + if (c == 0) + /* End of name */ + break; + else if (c <= 63) { + const char *label; + + /* Literal label */ + label = (const char *)&optval[pos]; + pos += c; + if (pos > optlen) + return -EMSGSIZE; + + if (!GREEDY_REALLOC(ret, allocated, n + !first + DNS_LABEL_ESCAPED_MAX)) { + r = -ENOMEM; + goto fail; + } + + if (first) + first = false; + else + ret[n++] = '.'; + + r = dns_label_escape(label, c, ret + n, DNS_LABEL_ESCAPED_MAX); + if (r < 0) + goto fail; + + n += r; + continue; + } else { + r = -EBADMSG; + goto fail; + } + } + + if (!GREEDY_REALLOC(ret, allocated, n + 1)) { + r = -ENOMEM; + goto fail; + } + + ret[n] = 0; + + r = strv_extend(&names, ret); + if (r < 0) + goto fail; + + idx++; + } + + *str_arr = names; + names = NULL; + + return idx; + +fail: + return r; +} |