| /* SPDX-License-Identifier: LGPL-2.1+ */ |
| /*** |
| Copyright © 2014-2015 Intel Corporation. All rights reserved. |
| ***/ |
| |
| #include <errno.h> |
| #include <netinet/in.h> |
| #include <string.h> |
| |
| #include "sd-dhcp6-client.h" |
| |
| #include "alloc-util.h" |
| #include "dhcp6-internal.h" |
| #include "dhcp6-lease-internal.h" |
| #include "dhcp6-protocol.h" |
| #include "dns-domain.h" |
| #include "memory-util.h" |
| #include "sparse-endian.h" |
| #include "strv.h" |
| #include "unaligned.h" |
| |
| typedef struct DHCP6StatusOption { |
| struct DHCP6Option option; |
| be16_t status; |
| char msg[]; |
| } _packed_ DHCP6StatusOption; |
| |
| typedef struct DHCP6AddressOption { |
| struct DHCP6Option option; |
| struct iaaddr iaaddr; |
| uint8_t options[]; |
| } _packed_ DHCP6AddressOption; |
| |
| typedef struct DHCP6PDPrefixOption { |
| struct DHCP6Option option; |
| struct iapdprefix iapdprefix; |
| uint8_t options[]; |
| } _packed_ DHCP6PDPrefixOption; |
| |
| #define DHCP6_OPTION_IA_NA_LEN (sizeof(struct ia_na)) |
| #define DHCP6_OPTION_IA_PD_LEN (sizeof(struct ia_pd)) |
| #define DHCP6_OPTION_IA_TA_LEN (sizeof(struct ia_ta)) |
| |
| 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 + offsetof(DHCP6Option, data)) |
| return -ENOBUFS; |
| |
| option->code = htobe16(optcode); |
| option->len = htobe16(optlen); |
| |
| *buf += offsetof(DHCP6Option, data); |
| *buflen -= offsetof(DHCP6Option, data); |
| |
| 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; |
| |
| memcpy_safe(*buf, optval, optlen); |
| |
| *buf += optlen; |
| *buflen -= optlen; |
| |
| return 0; |
| } |
| |
| int dhcp6_option_append_ia(uint8_t **buf, size_t *buflen, const DHCP6IA *ia) { |
| uint16_t len; |
| uint8_t *ia_hdr; |
| size_t iaid_offset, ia_buflen, ia_addrlen = 0; |
| DHCP6Address *addr; |
| int r; |
| |
| assert_return(buf, -EINVAL); |
| assert_return(*buf, -EINVAL); |
| assert_return(buflen, -EINVAL); |
| assert_return(ia, -EINVAL); |
| |
| switch (ia->type) { |
| case SD_DHCP6_OPTION_IA_NA: |
| len = DHCP6_OPTION_IA_NA_LEN; |
| iaid_offset = offsetof(DHCP6IA, ia_na); |
| break; |
| |
| case SD_DHCP6_OPTION_IA_TA: |
| len = DHCP6_OPTION_IA_TA_LEN; |
| iaid_offset = offsetof(DHCP6IA, ia_ta); |
| break; |
| |
| default: |
| return -EINVAL; |
| } |
| |
| if (*buflen < offsetof(DHCP6Option, data) + len) |
| return -ENOBUFS; |
| |
| ia_hdr = *buf; |
| ia_buflen = *buflen; |
| |
| *buf += offsetof(DHCP6Option, data); |
| *buflen -= offsetof(DHCP6Option, data); |
| |
| memcpy(*buf, (char*) ia + iaid_offset, 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 += offsetof(DHCP6Option, data) + sizeof(addr->iaaddr); |
| } |
| |
| r = option_append_hdr(&ia_hdr, &ia_buflen, ia->type, len + ia_addrlen); |
| if (r < 0) |
| return r; |
| |
| return 0; |
| } |
| |
| int dhcp6_option_append_fqdn(uint8_t **buf, size_t *buflen, const char *fqdn) { |
| uint8_t buffer[1 + DNS_WIRE_FORMAT_HOSTNAME_MAX]; |
| int r; |
| |
| assert_return(buf && *buf && buflen && fqdn, -EINVAL); |
| |
| buffer[0] = DHCP6_FQDN_FLAG_S; /* Request server to perform AAAA RR DNS updates */ |
| |
| /* Store domain name after flags field */ |
| r = dns_name_to_wire_format(fqdn, buffer + 1, sizeof(buffer) - 1, false); |
| if (r <= 0) |
| return r; |
| |
| /* |
| * According to RFC 4704, chapter 4.2 only add terminating zero-length |
| * label in case a FQDN is provided. Since dns_name_to_wire_format |
| * always adds terminating zero-length label remove if only a hostname |
| * is provided. |
| */ |
| if (dns_name_is_single_label(fqdn)) |
| r--; |
| |
| r = dhcp6_option_append(buf, buflen, SD_DHCP6_OPTION_FQDN, 1 + r, buffer); |
| |
| return r; |
| } |
| |
| int dhcp6_option_append_pd(uint8_t *buf, size_t len, const DHCP6IA *pd) { |
| DHCP6Option *option = (DHCP6Option *)buf; |
| size_t i = sizeof(*option) + sizeof(pd->ia_pd); |
| DHCP6Address *prefix; |
| |
| assert_return(buf, -EINVAL); |
| assert_return(pd, -EINVAL); |
| assert_return(pd->type == SD_DHCP6_OPTION_IA_PD, -EINVAL); |
| |
| if (len < i) |
| return -ENOBUFS; |
| |
| option->code = htobe16(SD_DHCP6_OPTION_IA_PD); |
| |
| memcpy(&option->data, &pd->ia_pd, sizeof(pd->ia_pd)); |
| |
| LIST_FOREACH(addresses, prefix, pd->addresses) { |
| DHCP6PDPrefixOption *prefix_opt; |
| |
| if (len < i + sizeof(*prefix_opt)) |
| return -ENOBUFS; |
| |
| prefix_opt = (DHCP6PDPrefixOption *)&buf[i]; |
| prefix_opt->option.code = htobe16(SD_DHCP6_OPTION_IA_PD_PREFIX); |
| prefix_opt->option.len = htobe16(sizeof(prefix_opt->iapdprefix)); |
| |
| memcpy(&prefix_opt->iapdprefix, &prefix->iapdprefix, |
| sizeof(struct iapdprefix)); |
| |
| i += sizeof(*prefix_opt); |
| } |
| |
| option->len = htobe16(i - sizeof(*option)); |
| |
| return i; |
| } |
| |
| 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 < offsetof(DHCP6Option, data)) |
| 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_status(DHCP6Option *option, size_t len) { |
| DHCP6StatusOption *statusopt = (DHCP6StatusOption *)option; |
| |
| if (len < sizeof(DHCP6StatusOption) || |
| be16toh(option->len) + offsetof(DHCP6Option, data) < sizeof(DHCP6StatusOption)) |
| return -ENOBUFS; |
| |
| return be16toh(statusopt->status); |
| } |
| |
| static int dhcp6_option_parse_address(DHCP6Option *option, DHCP6IA *ia, |
| uint32_t *lifetime_valid) { |
| DHCP6AddressOption *addr_option = (DHCP6AddressOption *)option; |
| DHCP6Address *addr; |
| uint32_t lt_valid, lt_pref; |
| int r; |
| |
| if (be16toh(option->len) + offsetof(DHCP6Option, data) < sizeof(*addr_option)) |
| return -ENOBUFS; |
| |
| lt_valid = be32toh(addr_option->iaaddr.lifetime_valid); |
| lt_pref = be32toh(addr_option->iaaddr.lifetime_preferred); |
| |
| if (lt_valid == 0 || lt_pref > lt_valid) { |
| log_dhcp6_client(client, "Valid lifetime of an IA address is zero or preferred lifetime %d > valid lifetime %d", |
| lt_pref, lt_valid); |
| |
| return 0; |
| } |
| |
| if (be16toh(option->len) + offsetof(DHCP6Option, data) > sizeof(*addr_option)) { |
| r = dhcp6_option_parse_status((DHCP6Option *)addr_option->options, be16toh(option->len) + offsetof(DHCP6Option, data) - sizeof(*addr_option)); |
| if (r != 0) |
| return r < 0 ? r: 0; |
| } |
| |
| addr = new0(DHCP6Address, 1); |
| if (!addr) |
| return -ENOMEM; |
| |
| LIST_INIT(addresses, addr); |
| memcpy(&addr->iaaddr, option->data, sizeof(addr->iaaddr)); |
| |
| LIST_PREPEND(addresses, ia->addresses, addr); |
| |
| *lifetime_valid = be32toh(addr->iaaddr.lifetime_valid); |
| |
| return 0; |
| } |
| |
| static int dhcp6_option_parse_pdprefix(DHCP6Option *option, DHCP6IA *ia, |
| uint32_t *lifetime_valid) { |
| DHCP6PDPrefixOption *pdprefix_option = (DHCP6PDPrefixOption *)option; |
| DHCP6Address *prefix; |
| uint32_t lt_valid, lt_pref; |
| int r; |
| |
| if (be16toh(option->len) + offsetof(DHCP6Option, data) < sizeof(*pdprefix_option)) |
| return -ENOBUFS; |
| |
| lt_valid = be32toh(pdprefix_option->iapdprefix.lifetime_valid); |
| lt_pref = be32toh(pdprefix_option->iapdprefix.lifetime_preferred); |
| |
| if (lt_valid == 0 || lt_pref > lt_valid) { |
| log_dhcp6_client(client, "Valid lifetieme of a PD prefix is zero or preferred lifetime %d > valid lifetime %d", |
| lt_pref, lt_valid); |
| |
| return 0; |
| } |
| |
| if (be16toh(option->len) + offsetof(DHCP6Option, data) > sizeof(*pdprefix_option)) { |
| r = dhcp6_option_parse_status((DHCP6Option *)pdprefix_option->options, be16toh(option->len) + offsetof(DHCP6Option, data) - sizeof(*pdprefix_option)); |
| if (r != 0) |
| return r < 0 ? r: 0; |
| } |
| |
| prefix = new0(DHCP6Address, 1); |
| if (!prefix) |
| return -ENOMEM; |
| |
| LIST_INIT(addresses, prefix); |
| memcpy(&prefix->iapdprefix, option->data, sizeof(prefix->iapdprefix)); |
| |
| LIST_PREPEND(addresses, ia->addresses, prefix); |
| |
| *lifetime_valid = be32toh(prefix->iapdprefix.lifetime_valid); |
| |
| return 0; |
| } |
| |
| int dhcp6_option_parse_ia(DHCP6Option *iaoption, DHCP6IA *ia) { |
| uint16_t iatype, optlen; |
| size_t i, len; |
| int r = 0, status; |
| uint16_t opt; |
| size_t iaaddr_offset; |
| uint32_t lt_t1, lt_t2, lt_valid = 0, lt_min = UINT32_MAX; |
| |
| assert_return(ia, -EINVAL); |
| assert_return(!ia->addresses, -EINVAL); |
| |
| iatype = be16toh(iaoption->code); |
| len = be16toh(iaoption->len); |
| |
| switch (iatype) { |
| case SD_DHCP6_OPTION_IA_NA: |
| |
| if (len < DHCP6_OPTION_IA_NA_LEN) |
| return -ENOBUFS; |
| |
| iaaddr_offset = DHCP6_OPTION_IA_NA_LEN; |
| memcpy(&ia->ia_na, iaoption->data, sizeof(ia->ia_na)); |
| |
| lt_t1 = be32toh(ia->ia_na.lifetime_t1); |
| lt_t2 = be32toh(ia->ia_na.lifetime_t2); |
| |
| if (lt_t1 && lt_t2 && lt_t1 > lt_t2) { |
| log_dhcp6_client(client, "IA NA T1 %ds > T2 %ds", |
| lt_t1, lt_t2); |
| return -EINVAL; |
| } |
| |
| break; |
| |
| case SD_DHCP6_OPTION_IA_PD: |
| |
| if (len < sizeof(ia->ia_pd)) |
| return -ENOBUFS; |
| |
| iaaddr_offset = sizeof(ia->ia_pd); |
| memcpy(&ia->ia_pd, iaoption->data, sizeof(ia->ia_pd)); |
| |
| lt_t1 = be32toh(ia->ia_pd.lifetime_t1); |
| lt_t2 = be32toh(ia->ia_pd.lifetime_t2); |
| |
| if (lt_t1 && lt_t2 && lt_t1 > lt_t2) { |
| log_dhcp6_client(client, "IA PD T1 %ds > T2 %ds", |
| lt_t1, lt_t2); |
| return -EINVAL; |
| } |
| |
| break; |
| |
| case SD_DHCP6_OPTION_IA_TA: |
| if (len < DHCP6_OPTION_IA_TA_LEN) |
| return -ENOBUFS; |
| |
| iaaddr_offset = DHCP6_OPTION_IA_TA_LEN; |
| memcpy(&ia->ia_ta.id, iaoption->data, sizeof(ia->ia_ta)); |
| |
| break; |
| |
| default: |
| return -ENOMSG; |
| } |
| |
| ia->type = iatype; |
| i = iaaddr_offset; |
| |
| while (i < len) { |
| DHCP6Option *option = (DHCP6Option *)&iaoption->data[i]; |
| |
| if (len < i + sizeof(*option) || len < i + sizeof(*option) + be16toh(option->len)) |
| return -ENOBUFS; |
| |
| opt = be16toh(option->code); |
| optlen = be16toh(option->len); |
| |
| switch (opt) { |
| case SD_DHCP6_OPTION_IAADDR: |
| |
| if (!IN_SET(ia->type, SD_DHCP6_OPTION_IA_NA, SD_DHCP6_OPTION_IA_TA)) { |
| log_dhcp6_client(client, "IA Address option not in IA NA or TA option"); |
| return -EINVAL; |
| } |
| |
| r = dhcp6_option_parse_address(option, ia, <_valid); |
| if (r < 0) |
| return r; |
| |
| if (lt_valid < lt_min) |
| lt_min = lt_valid; |
| |
| break; |
| |
| case SD_DHCP6_OPTION_IA_PD_PREFIX: |
| |
| if (!IN_SET(ia->type, SD_DHCP6_OPTION_IA_PD)) { |
| log_dhcp6_client(client, "IA PD Prefix option not in IA PD option"); |
| return -EINVAL; |
| } |
| |
| r = dhcp6_option_parse_pdprefix(option, ia, <_valid); |
| if (r < 0) |
| return r; |
| |
| if (lt_valid < lt_min) |
| lt_min = lt_valid; |
| |
| break; |
| |
| case SD_DHCP6_OPTION_STATUS_CODE: |
| |
| status = dhcp6_option_parse_status(option, optlen + offsetof(DHCP6Option, data)); |
| if (status < 0) |
| return status; |
| if (status > 0) { |
| log_dhcp6_client(client, "IA status %d", |
| status); |
| |
| return -EINVAL; |
| } |
| |
| break; |
| |
| default: |
| log_dhcp6_client(client, "Unknown IA option %d", opt); |
| break; |
| } |
| |
| i += sizeof(*option) + optlen; |
| } |
| |
| switch(iatype) { |
| case SD_DHCP6_OPTION_IA_NA: |
| if (!ia->ia_na.lifetime_t1 && !ia->ia_na.lifetime_t2) { |
| lt_t1 = lt_min / 2; |
| lt_t2 = lt_min / 10 * 8; |
| ia->ia_na.lifetime_t1 = htobe32(lt_t1); |
| ia->ia_na.lifetime_t2 = htobe32(lt_t2); |
| |
| log_dhcp6_client(client, "Computed IA NA T1 %ds and T2 %ds as both were zero", |
| lt_t1, lt_t2); |
| } |
| |
| break; |
| |
| case SD_DHCP6_OPTION_IA_PD: |
| if (!ia->ia_pd.lifetime_t1 && !ia->ia_pd.lifetime_t2) { |
| lt_t1 = lt_min / 2; |
| lt_t2 = lt_min / 10 * 8; |
| ia->ia_pd.lifetime_t1 = htobe32(lt_t1); |
| ia->ia_pd.lifetime_t2 = htobe32(lt_t2); |
| |
| log_dhcp6_client(client, "Computed IA PD T1 %ds and T2 %ds as both were zero", |
| lt_t1, lt_t2); |
| } |
| |
| break; |
| |
| default: |
| break; |
| } |
| |
| return 0; |
| } |
| |
| 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_strv_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 (;;) { |
| const char *label; |
| uint8_t c; |
| |
| c = optval[pos++]; |
| |
| if (c == 0) |
| /* End of name */ |
| break; |
| if (c > 63) |
| return -EBADMSG; |
| |
| /* 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)) |
| return -ENOMEM; |
| |
| if (first) |
| first = false; |
| else |
| ret[n++] = '.'; |
| |
| r = dns_label_escape(label, c, ret + n, DNS_LABEL_ESCAPED_MAX); |
| if (r < 0) |
| return r; |
| |
| n += r; |
| } |
| |
| if (n == 0) |
| continue; |
| |
| if (!GREEDY_REALLOC(ret, allocated, n + 1)) |
| return -ENOMEM; |
| |
| ret[n] = 0; |
| |
| r = strv_extend(&names, ret); |
| if (r < 0) |
| return r; |
| |
| idx++; |
| } |
| |
| *str_arr = TAKE_PTR(names); |
| |
| return idx; |
| } |