diff options
Diffstat (limited to 'dhcpv6.c')
| -rw-r--r-- | dhcpv6.c | 99 |
1 files changed, 84 insertions, 15 deletions
@@ -48,6 +48,7 @@ struct opt_hdr { # define STATUS_NOTONLINK htons_constant(4) # define OPT_DNS_SERVERS htons_constant(23) # define OPT_DNS_SEARCH htons_constant(24) +# define OPT_CLIENT_FQDN htons_constant(39) #define STR_NOTONLINK "Prefix not appropriate for link." uint16_t l; @@ -58,6 +59,9 @@ struct opt_hdr { sizeof(struct opt_hdr)) #define OPT_VSIZE(x) (sizeof(struct opt_##x) - \ sizeof(struct opt_hdr)) +#define OPT_MAX_SIZE IPV6_MIN_MTU - (sizeof(struct ipv6hdr) + \ + sizeof(struct udphdr) + \ + sizeof(struct msg_hdr)) /** * struct opt_client_id - DHCPv6 Client Identifier option @@ -164,6 +168,18 @@ struct opt_dns_search { } __attribute__((packed)); /** + * struct opt_client_fqdn - Client FQDN option (RFC 4704) + * @hdr: Option header + * @flags: Flags described by RFC 4704 + * @domain_name: Client FQDN + */ +struct opt_client_fqdn { + struct opt_hdr hdr; + uint8_t flags; + char domain_name[PASST_MAXDNAME]; +} __attribute__((packed)); + +/** * struct msg_hdr - DHCPv6 client/server message header * @type: DHCP message type * @xid: Transaction ID for message exchange @@ -193,6 +209,7 @@ struct msg_hdr { * @client_id: Client Identifier, variable length * @dns_servers: DNS Recursive Name Server, here just for storage size * @dns_search: Domain Search List, here just for storage size + * @client_fqdn: Client FQDN, variable length */ static struct resp_t { struct msg_hdr hdr; @@ -203,6 +220,7 @@ static struct resp_t { struct opt_client_id client_id; struct opt_dns_servers dns_servers; struct opt_dns_search dns_search; + struct opt_client_fqdn client_fqdn; } __attribute__((__packed__)) resp = { { 0 }, SERVER_ID, @@ -228,6 +246,10 @@ static struct resp_t { { { OPT_DNS_SEARCH, 0, }, { 0 }, }, + + { { OPT_CLIENT_FQDN, 0, }, + 0, { 0 }, + }, }; static const struct opt_status_code sc_not_on_link = { @@ -346,7 +368,6 @@ static size_t dhcpv6_dns_fill(const struct ctx *c, char *buf, int offset) { struct opt_dns_servers *srv = NULL; struct opt_dns_search *srch = NULL; - char *p = NULL; int i; if (c->no_dhcp_dns) @@ -383,35 +404,82 @@ search: if (!name_len) continue; + name_len += 2; /* Length byte for first label, and terminator */ + if (name_len > + NS_MAXDNAME + 1 /* Length byte for first label */ || + name_len > 255) { + debug("DHCP: DNS search name '%s' too long, skipping", + c->dns_search[i].n); + continue; + } + if (!srch) { srch = (struct opt_dns_search *)(buf + offset); offset += sizeof(struct opt_hdr); srch->hdr.t = OPT_DNS_SEARCH; srch->hdr.l = 0; - p = srch->list; } - *p = '.'; - p = stpncpy(p + 1, c->dns_search[i].n, name_len); - p++; - srch->hdr.l += name_len + 2; - offset += name_len + 2; + encode_domain_name(buf + offset, c->dns_search[i].n); + + srch->hdr.l += name_len; + offset += name_len; + } - if (srch) { - for (i = 0; i < srch->hdr.l; i++) { - if (srch->list[i] == '.') { - srch->list[i] = strcspn(srch->list + i + 1, - "."); - } - } + if (srch) srch->hdr.l = htons(srch->hdr.l); - } return offset; } /** + * dhcpv6_client_fqdn_fill() - Fill in client FQDN option + * @c: Execution context + * @buf: Response message buffer where options will be appended + * @offset: Offset in message buffer for new options + * + * Return: updated length of response message buffer. + */ +static size_t dhcpv6_client_fqdn_fill(const struct pool *p, const struct ctx *c, + char *buf, int offset) + +{ + struct opt_client_fqdn const *req_opt; + struct opt_client_fqdn *o; + size_t opt_len; + + opt_len = strlen(c->fqdn); + if (opt_len == 0) { + return offset; + } + + opt_len += 2; /* Length byte for first label, and terminator */ + if (opt_len > OPT_MAX_SIZE - (offset + + sizeof(struct opt_hdr) + + 1 /* flags */ )) { + debug("DHCPv6: client FQDN option doesn't fit, skipping"); + return offset; + } + + o = (struct opt_client_fqdn *)(buf + offset); + encode_domain_name(o->domain_name, c->fqdn); + req_opt = (struct opt_client_fqdn *)dhcpv6_opt(p, &(size_t){ 0 }, + OPT_CLIENT_FQDN); + if (req_opt && req_opt->flags & 0x01 /* S flag */) + o->flags = 0x02 /* O flag */; + else + o->flags = 0x00; + + opt_len++; + + o->hdr.t = OPT_CLIENT_FQDN; + o->hdr.l = htons(opt_len); + + return offset + sizeof(struct opt_hdr) + opt_len; +} + +/** * dhcpv6() - Check if this is a DHCPv6 message, reply as needed * @c: Execution context * @p: Packet pool, single packet starting from UDP header @@ -544,6 +612,7 @@ int dhcpv6(struct ctx *c, const struct pool *p, n = offsetof(struct resp_t, client_id) + sizeof(struct opt_hdr) + ntohs(client_id->l); n = dhcpv6_dns_fill(c, (char *)&resp, n); + n = dhcpv6_client_fqdn_fill(p, c, (char *)&resp, n); resp.hdr.xid = mh->xid; |