nd6: add support for RDNSS option (as per RFC 6106)

This commit is contained in:
sg 2016-12-14 22:12:14 +01:00
parent 4e3cf61571
commit 6b1950ec24
4 changed files with 67 additions and 0 deletions

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@ -6,6 +6,9 @@ HISTORY
++ New features:
2016-12-14: Jan Breuer:
opt.h, ndc.h/.c: add support for RDNSS option (as per RFC 6106)
2016-12-14: David van Moolenbroek
* opt.h, nd6.c: Added LWIP_HOOK_ND6_GET_GW()

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@ -60,6 +60,7 @@
#include "lwip/mld6.h"
#include "lwip/ip.h"
#include "lwip/stats.h"
#include "lwip/dns.h"
#include <string.h>
@ -394,6 +395,10 @@ nd6_input(struct pbuf *p, struct netif *inp)
struct ra_header *ra_hdr;
u8_t *buffer; /* Used to copy options. */
u16_t offset;
#ifdef LWIP_ND6_RDNSS_MAX_DNS_SERVERS
/* There can by multiple RDNSS options per RA */
u8_t rdnss_server_idx = 0;
#endif /* LWIP_ND6_RDNSS_MAX_DNS_SERVERS */
/* Check that RA header fits in packet. */
if (p->len < sizeof(struct ra_header)) {
@ -538,6 +543,34 @@ nd6_input(struct pbuf *p, struct netif *inp)
route_opt = (struct route_option *)buffer;*/
break;
#if LWIP_ND6_RDNSS_MAX_DNS_SERVERS
case ND6_OPTION_TYPE_RDNSS:
{
u8_t num, n;
struct rdnss_option * rdnss_opt;
rdnss_opt = (struct rdnss_option *)buffer;
num = (rdnss_opt->length - 1) / 2;
for (n = 0; (rdnss_server_idx < DNS_MAX_SERVERS) && (n < num); n++) {
/* Get a memory-aligned copy of the prefix. */
ip6_addr_set(ip6_current_dest_addr(), &(rdnss_opt->rdnss_address[n]));
if (htonl(rdnss_opt->lifetime) > 0) {
/* TODO implement Lifetime > 0 */
dns_setserver(rdnss_server_idx++, ip_current_dest_addr());
} else {
/* TODO implement DNS removal in dns.c */
u8_t s;
for (s = 0; s < DNS_MAX_SERVERS; s++) {
const ip_addr_t *addr = dns_getserver(s);
if(ip_addr_cmp(addr, ip_current_dest_addr())) {
dns_setserver(s, NULL);
}
}
}
}
break;
}
#endif /* LWIP_ND6_RDNSS_MAX_DNS_SERVERS */
default:
/* Unrecognized option, abort. */
ND6_STATS_INC(nd6.proterr);

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@ -2378,6 +2378,14 @@
#define LWIP_ND6_TCP_REACHABILITY_HINTS 1
#endif
/**
* LWIP_ND6_RDNSS_MAX_DNS_SERVERS > 0: Use IPv6 Router Advertisement Recursive
* DNS Server Option (as per RFC 6106) to copy a defined maximum number of DNS
* servers to the DNS module.
*/
#if !defined LWIP_ND6_RDNSS_MAX_DNS_SERVERS || defined __DOXYGEN__
#define LWIP_ND6_RDNSS_MAX_DNS_SERVERS 0
#endif
/**
* @}
*/

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@ -247,6 +247,29 @@ PACK_STRUCT_END
# include "arch/epstruct.h"
#endif
/** Recursive DNS Server Option. */
#if LWIP_ND6_RDNSS_MAX_DNS_SERVERS
#define LWIP_RDNSS_OPTION_MAX_SERVERS LWIP_ND6_RDNSS_MAX_DNS_SERVERS
#else
#define LWIP_RDNSS_OPTION_MAX_SERVERS 1
#endif
#define ND6_OPTION_TYPE_RDNSS (25)
#ifdef PACK_STRUCT_USE_INCLUDES
# include "arch/bpstruct.h"
#endif
PACK_STRUCT_BEGIN
struct rdnss_option {
PACK_STRUCT_FLD_8(u8_t type);
PACK_STRUCT_FLD_8(u8_t length);
PACK_STRUCT_FIELD(u16_t reserved);
PACK_STRUCT_FIELD(u32_t lifetime);
PACK_STRUCT_FLD_S(ip6_addr_p_t rdnss_address[LWIP_RDNSS_OPTION_MAX_SERVERS]);
} PACK_STRUCT_STRUCT;
PACK_STRUCT_END
#ifdef PACK_STRUCT_USE_INCLUDES
# include "arch/epstruct.h"
#endif
#ifdef __cplusplus
}
#endif