From d7ff226ceb6044445788c403686f5a4262d4ebae Mon Sep 17 00:00:00 2001 From: Beniamino Galvani Date: Thu, 6 Aug 2020 10:49:07 +0200 Subject: [PATCH] systemd: dhcp6: parse the FQDN option Parse option 39 (Client Fully Qualified Domain Name, RFC 4704) from the DHCP reply, which specifies the FQDN assigned by the server to the client. https://github.com/systemd/systemd/commit/c43eea9f2effbb066901a61eafef473558d37b0f (cherry picked from commit 813fb7d64ee4cb0f935a3a15b9f5b8f5771655da) (cherry picked from commit 504a3486ed05f1d1a50fb3338f0617f7386a9359) --- .../src/libsystemd-network/dhcp6-internal.h | 5 +- .../libsystemd-network/dhcp6-lease-internal.h | 2 + .../src/libsystemd-network/dhcp6-option.c | 130 ++++++++++++------ .../src/libsystemd-network/sd-dhcp6-client.c | 7 + .../src/libsystemd-network/sd-dhcp6-lease.c | 39 +++++- src/systemd/src/systemd/sd-dhcp6-lease.h | 1 + 6 files changed, 135 insertions(+), 49 deletions(-) diff --git a/src/systemd/src/libsystemd-network/dhcp6-internal.h b/src/systemd/src/libsystemd-network/dhcp6-internal.h index 517e357d3d..a32599387e 100644 --- a/src/systemd/src/libsystemd-network/dhcp6-internal.h +++ b/src/systemd/src/libsystemd-network/dhcp6-internal.h @@ -94,8 +94,9 @@ int dhcp6_option_parse_ia(DHCP6Option *iaoption, DHCP6IA *ia); int dhcp6_option_parse_ip6addrs(uint8_t *optval, uint16_t optlen, struct in6_addr **addrs, size_t count, size_t *allocated); -int dhcp6_option_parse_domainname(const uint8_t *optval, uint16_t optlen, - char ***str_arr); +int dhcp6_option_parse_domainname_list(const uint8_t *optval, uint16_t optlen, + char ***str_arr); +int dhcp6_option_parse_domainname(const uint8_t *optval, uint16_t optlen, char **str); int dhcp6_network_bind_udp_socket(int index, struct in6_addr *address); int dhcp6_network_send_udp_socket(int s, struct in6_addr *address, diff --git a/src/systemd/src/libsystemd-network/dhcp6-lease-internal.h b/src/systemd/src/libsystemd-network/dhcp6-lease-internal.h index e004f48b4e..df6c95e0b3 100644 --- a/src/systemd/src/libsystemd-network/dhcp6-lease-internal.h +++ b/src/systemd/src/libsystemd-network/dhcp6-lease-internal.h @@ -35,6 +35,7 @@ struct sd_dhcp6_lease { size_t ntp_allocated; char **ntp_fqdn; size_t ntp_fqdn_count; + char *fqdn; }; int dhcp6_lease_ia_rebind_expire(const DHCP6IA *ia, uint32_t *expire); @@ -57,5 +58,6 @@ int dhcp6_lease_set_domains(sd_dhcp6_lease *lease, uint8_t *optval, int dhcp6_lease_set_ntp(sd_dhcp6_lease *lease, uint8_t *optval, size_t optlen); int dhcp6_lease_set_sntp(sd_dhcp6_lease *lease, uint8_t *optval, size_t optlen) ; +int dhcp6_lease_set_fqdn(sd_dhcp6_lease *lease, const uint8_t *optval, size_t optlen); int dhcp6_lease_new(sd_dhcp6_lease **ret); diff --git a/src/systemd/src/libsystemd-network/dhcp6-option.c b/src/systemd/src/libsystemd-network/dhcp6-option.c index 72cd9a4c80..55cdb0e00f 100644 --- a/src/systemd/src/libsystemd-network/dhcp6-option.c +++ b/src/systemd/src/libsystemd-network/dhcp6-option.c @@ -534,8 +534,87 @@ int dhcp6_option_parse_ip6addrs(uint8_t *optval, uint16_t optlen, return count; } -int dhcp6_option_parse_domainname(const uint8_t *optval, uint16_t optlen, char ***str_arr) { - size_t pos = 0, idx = 0; +static int parse_domain(const uint8_t **data, uint16_t *len, char **out_domain) { + _cleanup_free_ char *ret = NULL; + size_t n = 0, allocated = 0; + const uint8_t *optval = *data; + uint16_t optlen = *len; + bool first = true; + int r; + + if (optlen <= 1) + return -ENODATA; + + for (;;) { + const char *label; + uint8_t c; + + if (optlen == 0) + break; + + c = *optval; + optval++; + optlen--; + + if (c == 0) + /* End label */ + break; + if (c > 63) + return -EBADMSG; + if (c > optlen) + return -EMSGSIZE; + + /* Literal label */ + label = (const char *)optval; + optval += c; + optlen -= c; + + 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) { + if (!GREEDY_REALLOC(ret, allocated, n + 1)) + return -ENOMEM; + ret[n] = 0; + } + + *out_domain = TAKE_PTR(ret); + *data = optval; + *len = optlen; + + return n; +} + +int dhcp6_option_parse_domainname(const uint8_t *optval, uint16_t optlen, char **str) { + _cleanup_free_ char *domain = NULL; + int r; + + r = parse_domain(&optval, &optlen, &domain); + if (r < 0) + return r; + if (r == 0) + return -ENODATA; + if (optlen != 0) + return -EINVAL; + + *str = TAKE_PTR(domain); + return 0; +} + +int dhcp6_option_parse_domainname_list(const uint8_t *optval, uint16_t optlen, char ***str_arr) { + size_t idx = 0; _cleanup_strv_free_ char **names = NULL; int r; @@ -544,52 +623,15 @@ int dhcp6_option_parse_domainname(const uint8_t *optval, uint16_t optlen, char * if (optval[optlen - 1] != '\0') return -EINVAL; - while (pos < optlen) { + while (optlen > 0) { _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) + r = parse_domain(&optval, &optlen, &ret); + if (r < 0) + return r; + if (r == 0) continue; - if (!GREEDY_REALLOC(ret, allocated, n + 1)) - return -ENOMEM; - - ret[n] = 0; - r = strv_extend(&names, ret); if (r < 0) return r; diff --git a/src/systemd/src/libsystemd-network/sd-dhcp6-client.c b/src/systemd/src/libsystemd-network/sd-dhcp6-client.c index e1150f9806..948e72f523 100644 --- a/src/systemd/src/libsystemd-network/sd-dhcp6-client.c +++ b/src/systemd/src/libsystemd-network/sd-dhcp6-client.c @@ -1023,6 +1023,13 @@ static int client_parse_message( break; + case SD_DHCP6_OPTION_FQDN: + r = dhcp6_lease_set_fqdn(lease, optval, optlen); + if (r < 0) + return r; + + break; + case SD_DHCP6_OPTION_INFORMATION_REFRESH_TIME: if (optlen != 4) return -EINVAL; diff --git a/src/systemd/src/libsystemd-network/sd-dhcp6-lease.c b/src/systemd/src/libsystemd-network/sd-dhcp6-lease.c index 35caec7a23..061f8853d2 100644 --- a/src/systemd/src/libsystemd-network/sd-dhcp6-lease.c +++ b/src/systemd/src/libsystemd-network/sd-dhcp6-lease.c @@ -238,7 +238,7 @@ int dhcp6_lease_set_domains(sd_dhcp6_lease *lease, uint8_t *optval, if (!optlen) return 0; - r = dhcp6_option_parse_domainname(optval, optlen, &domains); + r = dhcp6_option_parse_domainname_list(optval, optlen, &domains); if (r < 0) return 0; @@ -296,8 +296,8 @@ int dhcp6_lease_set_ntp(sd_dhcp6_lease *lease, uint8_t *optval, size_t optlen) { break; case DHCP6_NTP_SUBOPTION_SRV_FQDN: - r = dhcp6_option_parse_domainname(subval, sublen, - &servers); + r = dhcp6_option_parse_domainname_list(subval, sublen, + &servers); if (r < 0) return 0; @@ -367,6 +367,38 @@ int sd_dhcp6_lease_get_ntp_fqdn(sd_dhcp6_lease *lease, char ***ntp_fqdn) { return -ENOENT; } +int dhcp6_lease_set_fqdn(sd_dhcp6_lease *lease, const uint8_t *optval, + size_t optlen) { + int r; + char *fqdn; + + assert_return(lease, -EINVAL); + assert_return(optval, -EINVAL); + + if (optlen < 2) + return -ENODATA; + + /* Ignore the flags field, it doesn't carry any useful + information for clients. */ + r = dhcp6_option_parse_domainname(optval + 1, optlen - 1, &fqdn); + if (r < 0) + return r; + + return free_and_replace(lease->fqdn, fqdn); +} + +int sd_dhcp6_lease_get_fqdn(sd_dhcp6_lease *lease, const char **fqdn) { + assert_return(lease, -EINVAL); + assert_return(fqdn, -EINVAL); + + if (lease->fqdn) { + *fqdn = lease->fqdn; + return 0; + } + + return -ENOENT; +} + static sd_dhcp6_lease *dhcp6_lease_free(sd_dhcp6_lease *lease) { assert(lease); @@ -375,6 +407,7 @@ static sd_dhcp6_lease *dhcp6_lease_free(sd_dhcp6_lease *lease) { dhcp6_lease_free_ia(&lease->pd); free(lease->dns); + free(lease->fqdn); lease->domains = strv_free(lease->domains); diff --git a/src/systemd/src/systemd/sd-dhcp6-lease.h b/src/systemd/src/systemd/sd-dhcp6-lease.h index 33a32a6dc5..2ef2ab7aee 100644 --- a/src/systemd/src/systemd/sd-dhcp6-lease.h +++ b/src/systemd/src/systemd/sd-dhcp6-lease.h @@ -44,6 +44,7 @@ int sd_dhcp6_lease_get_domains(sd_dhcp6_lease *lease, char ***domains); int sd_dhcp6_lease_get_ntp_addrs(sd_dhcp6_lease *lease, struct in6_addr **addrs); int sd_dhcp6_lease_get_ntp_fqdn(sd_dhcp6_lease *lease, char ***ntp_fqdn); +int sd_dhcp6_lease_get_fqdn(sd_dhcp6_lease *lease, const char **fqdn); sd_dhcp6_lease *sd_dhcp6_lease_ref(sd_dhcp6_lease *lease); sd_dhcp6_lease *sd_dhcp6_lease_unref(sd_dhcp6_lease *lease);