/**
* Same as ipaddr_ntoa, but reentrant since a user-supplied buffer is used.
*
* @param addr ip6 address in network order to convert
* @param buf target buffer where the string is stored
* @param buflen length of buf
* @return either pointer to buf which now holds the ASCII
* representation of addr or NULL if buf was too small
*/
char *
ip6addr_ntoa_r(const ip6_addr_t *addr, char *buf, int buflen)
{
u32_t current_block_index, current_block_value, next_block_value;
s32_t i;
u8_t zero_flag, empty_block_flag;
#if LWIP_IPV4
if (ip6_addr_isipv4mappedipv6(addr)) {
/* This is an IPv4 mapped address */
ip4_addr_t addr4;
char *ret;
#define IP4MAPPED_HEADER "::FFFF:"
char *buf_ip4 = buf + sizeof(IP4MAPPED_HEADER) - 1;
int buflen_ip4 = buflen - sizeof(IP4MAPPED_HEADER) + 1;
if (buflen < (int)sizeof(IP4MAPPED_HEADER)) {
return NULL;
}
memcpy(buf, IP4MAPPED_HEADER, sizeof(IP4MAPPED_HEADER));
addr4.addr = addr->addr[3];
ret = ip4addr_ntoa_r(&addr4, buf_ip4, buflen_ip4);
if (ret != buf_ip4) {
return NULL;
}
return buf;
}
#endif /* LWIP_IPV4 */
i = 0;
empty_block_flag = 0; /* used to indicate a zero chain for "::' */
for (current_block_index = 0; current_block_index < 8; current_block_index++) {
/* get the current 16-bit block */
current_block_value = lwip_htonl(addr->addr[current_block_index >> 1]);
if ((current_block_index & 0x1) == 0) {
current_block_value = current_block_value >> 16;
}
current_block_value &= 0xffff;
/* Check for empty block. */
if (current_block_value == 0) {
if (current_block_index == 7 && empty_block_flag == 1) {
/* special case, we must render a ':' for the last block. */
buf[i++] = ':';
if (i >= buflen) {
return NULL;
}
break;
}
if (empty_block_flag == 0) {
/* generate empty block "::", but only if more than one contiguous zero block,
* according to current formatting suggestions RFC 5952. */
next_block_value = lwip_htonl(addr->addr[(current_block_index + 1) >> 1]);
if ((current_block_index & 0x1) == 0x01) {
next_block_value = next_block_value >> 16;
}
next_block_value &= 0xffff;
if (next_block_value == 0) {
empty_block_flag = 1;
buf[i++] = ':';
if (i >= buflen) {
return NULL;
}
continue; /* move on to next block. */
}
} else if (empty_block_flag == 1) {
/**
* This function is called by the network interface device driver when
* an IPv6 packet is received. The function does the basic checks of the
* IP header such as packet size being at least larger than the header
* size etc. If the packet was not destined for us, the packet is
* forwarded (using ip6_forward).
*
* Finally, the packet is sent to the upper layer protocol input function.
*
* @param p the received IPv6 packet (p->payload points to IPv6 header)
* @param inp the netif on which this packet was received
* @return ERR_OK if the packet was processed (could return ERR_* if it wasn't
* processed, but currently always returns ERR_OK)
*/
err_t
ip6_input(struct pbuf *p, struct netif *inp)
{
struct ip6_hdr *ip6hdr;
struct netif *netif;
u8_t nexth;
u16_t hlen; /* the current header length */
u8_t i;
#if 0 /*IP_ACCEPT_LINK_LAYER_ADDRESSING*/
@todo
int check_ip_src=1;
#endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
IP6_STATS_INC(ip6.recv);
/* identify the IP header */
ip6hdr = (struct ip6_hdr *)p->payload;
if (IP6H_V(ip6hdr) != 6) {
LWIP_DEBUGF(IP6_DEBUG | LWIP_DBG_LEVEL_WARNING, ("IPv6 packet dropped due to bad version number %"U32_F"\n",
IP6H_V(ip6hdr)));
pbuf_free(p);
IP6_STATS_INC(ip6.err);
IP6_STATS_INC(ip6.drop);
return ERR_OK;
}
#ifdef LWIP_HOOK_IP6_INPUT
if (LWIP_HOOK_IP6_INPUT(p, inp)) {
/* the packet has been eaten */
return ERR_OK;
}
#endif
/* header length exceeds first pbuf length, or ip length exceeds total pbuf length? */
if ((IP6_HLEN > p->len) || ((IP6H_PLEN(ip6hdr) + IP6_HLEN) > p->tot_len)) {
if (IP6_HLEN > p->len) {
LWIP_DEBUGF(IP6_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
("IPv6 header (len %"U16_F") does not fit in first pbuf (len %"U16_F"), IP packet dropped.\n",
(u16_t)IP6_HLEN, p->len));
}
if ((IP6H_PLEN(ip6hdr) + IP6_HLEN) > p->tot_len) {
LWIP_DEBUGF(IP6_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
("IPv6 (plen %"U16_F") is longer than pbuf (len %"U16_F"), IP packet dropped.\n",
(u16_t)(IP6H_PLEN(ip6hdr) + IP6_HLEN), p->tot_len));
}
/* free (drop) packet pbufs */
pbuf_free(p);
IP6_STATS_INC(ip6.lenerr);
IP6_STATS_INC(ip6.drop);
return ERR_OK;
}
/* Trim pbuf. This should have been done at the netif layer,
* but we'll do it anyway just to be sure that its done. */
pbuf_realloc(p, IP6_HLEN + IP6H_PLEN(ip6hdr));
/* copy IP addresses to aligned ip6_addr_t */
ip_addr_copy_from_ip6(ip_data.current_iphdr_dest, ip6hdr->dest);
ip_addr_copy_from_ip6(ip_data.current_iphdr_src, ip6hdr->src);
/* Don't accept virtual IPv4 mapped IPv6 addresses.
* Don't accept multicast source addresses. */
if (ip6_addr_isipv4mappedipv6(ip_2_ip6(&ip_data.current_iphdr_dest)) ||
ip6_addr_isipv4mappedipv6(ip_2_ip6(&ip_data.current_iphdr_src)) ||
ip6_addr_ismulticast(ip_2_ip6(&ip_data.current_iphdr_src))) {
IP6_STATS_INC(ip6.err);
IP6_STATS_INC(ip6.drop);
return ERR_OK;
}
/* current header pointer. */
ip_data.current_ip6_header = ip6hdr;
/* In netif, used in case we need to send ICMPv6 packets back. */
ip_data.current_netif = inp;
ip_data.current_input_netif = inp;
/* match packet against an interface, i.e. is this packet for us? */
if (ip6_addr_ismulticast(ip6_current_dest_addr())) {
/* Always joined to multicast if-local and link-local all-nodes group. */
if (ip6_addr_isallnodes_iflocal(ip6_current_dest_addr()) ||
ip6_addr_isallnodes_linklocal(ip6_current_dest_addr())) {
netif = inp;
}
#if LWIP_IPV6_MLD
else if (mld6_lookfor_group(inp, ip6_current_dest_addr())) {
netif = inp;
}
#else /* LWIP_IPV6_MLD */
else if (ip6_addr_issolicitednode(ip6_current_dest_addr())) {
/* Filter solicited node packets when MLD is not enabled
* (for Neighbor discovery). */
netif = NULL;
for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++) {
if (ip6_addr_isvalid(netif_ip6_addr_state(inp, i)) &&
ip6_addr_cmp_solicitednode(ip6_current_dest_addr(), netif_ip6_addr(inp, i))) {
netif = inp;
LWIP_DEBUGF(IP6_DEBUG, ("ip6_input: solicited node packet accepted on interface %c%c\n",
netif->name[0], netif->name[1]));
break;
}
}
}
#endif /* LWIP_IPV6_MLD */
else {
netif = NULL;
}
} else {
/* start trying with inp. if that's not acceptable, start walking the
list of configured netifs.
'first' is used as a boolean to mark whether we started walking the list */
int first = 1;
netif = inp;
do {
/* interface is up? */
if (netif_is_up(netif)) {
/* unicast to this interface address? address configured? */
for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++) {
if (ip6_addr_isvalid(netif_ip6_addr_state(netif, i)) &&
ip6_addr_cmp(ip6_current_dest_addr(), netif_ip6_addr(netif, i))) {
/* exit outer loop */
goto netif_found;
}
}
}
if (first) {
if (ip6_addr_islinklocal(ip6_current_dest_addr())
#if !LWIP_NETIF_LOOPBACK || LWIP_HAVE_LOOPIF
|| ip6_addr_isloopback(ip6_current_dest_addr())
#endif /* !LWIP_NETIF_LOOPBACK || LWIP_HAVE_LOOPIF */
) {
/* Do not match link-local addresses to other netifs. The loopback
* address is to be considered link-local and packets to it should be
* dropped on other interfaces, as per RFC 4291 Sec. 2.5.3. This
* requirement cannot be implemented in the case that loopback
* traffic is sent across a non-loopback interface, however.
*/
netif = NULL;
break;
}
first = 0;
netif = netif_list;
} else {
netif = netif->next;
}
if (netif == inp) {
netif = netif->next;
}
} while (netif != NULL);
netif_found:
LWIP_DEBUGF(IP6_DEBUG, ("ip6_input: packet accepted on interface %c%c\n",
netif ? netif->name[0] : 'X', netif? netif->name[1] : 'X'));
}
/* "::" packet source address? (used in duplicate address detection) */
if (ip6_addr_isany(ip6_current_src_addr()) &&
(!ip6_addr_issolicitednode(ip6_current_dest_addr()))) {
/* packet source is not valid */
/* free (drop) packet pbufs */
LWIP_DEBUGF(IP6_DEBUG, ("ip6_input: packet with src ANY_ADDRESS dropped\n"));
pbuf_free(p);
IP6_STATS_INC(ip6.drop);
goto ip6_input_cleanup;
}
/* packet not for us? */
if (netif == NULL) {
/* packet not for us, route or discard */
LWIP_DEBUGF(IP6_DEBUG | LWIP_DBG_TRACE, ("ip6_input: packet not for us.\n"));
#if LWIP_IPV6_FORWARD
/* non-multicast packet? */
if (!ip6_addr_ismulticast(ip6_current_dest_addr())) {
/* try to forward IP packet on (other) interfaces */
ip6_forward(p, ip6hdr, inp);
}
#endif /* LWIP_IPV6_FORWARD */
pbuf_free(p);
goto ip6_input_cleanup;
}
/* current netif pointer. */
ip_data.current_netif = netif;
/* Save next header type. */
nexth = IP6H_NEXTH(ip6hdr);
/* Init header length. */
hlen = ip_data.current_ip_header_tot_len = IP6_HLEN;
/* Move to payload. */
pbuf_header(p, -IP6_HLEN);
/* Process known option extension headers, if present. */
while (nexth != IP6_NEXTH_NONE)
{
switch (nexth) {
case IP6_NEXTH_HOPBYHOP:
LWIP_DEBUGF(IP6_DEBUG, ("ip6_input: packet with Hop-by-Hop options header\n"));
/* Get next header type. */
nexth = *((u8_t *)p->payload);
/* Get the header length. */
hlen = 8 * (1 + *((u8_t *)p->payload + 1));
ip_data.current_ip_header_tot_len += hlen;
/* Skip over this header. */
if (hlen > p->len) {
LWIP_DEBUGF(IP6_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
("IPv6 options header (hlen %"U16_F") does not fit in first pbuf (len %"U16_F"), IPv6 packet dropped.\n",
hlen, p->len));
/* free (drop) packet pbufs */
pbuf_free(p);
IP6_STATS_INC(ip6.lenerr);
IP6_STATS_INC(ip6.drop);
goto ip6_input_cleanup;
}
pbuf_header(p, -(s16_t)hlen);
break;
case IP6_NEXTH_DESTOPTS:
LWIP_DEBUGF(IP6_DEBUG, ("ip6_input: packet with Destination options header\n"));
/* Get next header type. */
nexth = *((u8_t *)p->payload);
/* Get the header length. */
hlen = 8 * (1 + *((u8_t *)p->payload + 1));
ip_data.current_ip_header_tot_len += hlen;
/* Skip over this header. */
if (hlen > p->len) {
LWIP_DEBUGF(IP6_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
("IPv6 options header (hlen %"U16_F") does not fit in first pbuf (len %"U16_F"), IPv6 packet dropped.\n",
hlen, p->len));
/* free (drop) packet pbufs */
pbuf_free(p);
IP6_STATS_INC(ip6.lenerr);
IP6_STATS_INC(ip6.drop);
goto ip6_input_cleanup;
}
pbuf_header(p, -(s16_t)hlen);
break;
case IP6_NEXTH_ROUTING:
LWIP_DEBUGF(IP6_DEBUG, ("ip6_input: packet with Routing header\n"));
/* Get next header type. */
nexth = *((u8_t *)p->payload);
/* Get the header length. */
hlen = 8 * (1 + *((u8_t *)p->payload + 1));
ip_data.current_ip_header_tot_len += hlen;
/* Skip over this header. */
if (hlen > p->len) {
LWIP_DEBUGF(IP6_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
("IPv6 options header (hlen %"U16_F") does not fit in first pbuf (len %"U16_F"), IPv6 packet dropped.\n",
hlen, p->len));
/* free (drop) packet pbufs */
pbuf_free(p);
IP6_STATS_INC(ip6.lenerr);
IP6_STATS_INC(ip6.drop);
goto ip6_input_cleanup;
}
pbuf_header(p, -(s16_t)hlen);
break;
case IP6_NEXTH_FRAGMENT:
{
struct ip6_frag_hdr *frag_hdr;
LWIP_DEBUGF(IP6_DEBUG, ("ip6_input: packet with Fragment header\n"));
frag_hdr = (struct ip6_frag_hdr *)p->payload;
/* Get next header type. */
nexth = frag_hdr->_nexth;
/* Fragment Header length. */
hlen = 8;
ip_data.current_ip_header_tot_len += hlen;
/* Make sure this header fits in current pbuf. */
if (hlen > p->len) {
LWIP_DEBUGF(IP6_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
("IPv6 options header (hlen %"U16_F") does not fit in first pbuf (len %"U16_F"), IPv6 packet dropped.\n",
hlen, p->len));
/* free (drop) packet pbufs */
pbuf_free(p);
IP6_FRAG_STATS_INC(ip6_frag.lenerr);
IP6_FRAG_STATS_INC(ip6_frag.drop);
goto ip6_input_cleanup;
}
/* Offset == 0 and more_fragments == 0? */
if ((frag_hdr->_fragment_offset &
PP_HTONS(IP6_FRAG_OFFSET_MASK | IP6_FRAG_MORE_FLAG)) == 0) {
/* This is a 1-fragment packet, usually a packet that we have
* already reassembled. Skip this header anc continue. */
pbuf_header(p, -(s16_t)hlen);
} else {
#if LWIP_IPV6_REASS
/* reassemble the packet */
p = ip6_reass(p);
/* packet not fully reassembled yet? */
if (p == NULL) {
goto ip6_input_cleanup;
}
/* Returned p point to IPv6 header.
* Update all our variables and pointers and continue. */
ip6hdr = (struct ip6_hdr *)p->payload;
nexth = IP6H_NEXTH(ip6hdr);
hlen = ip_data.current_ip_header_tot_len = IP6_HLEN;
pbuf_header(p, -IP6_HLEN);
#else /* LWIP_IPV6_REASS */
/* free (drop) packet pbufs */
LWIP_DEBUGF(IP6_DEBUG, ("ip6_input: packet with Fragment header dropped (with LWIP_IPV6_REASS==0)\n"));
pbuf_free(p);
IP6_STATS_INC(ip6.opterr);
IP6_STATS_INC(ip6.drop);
goto ip6_input_cleanup;
#endif /* LWIP_IPV6_REASS */
}
break;
}
default:
goto options_done;
break;
}
}
options_done:
/* p points to IPv6 header again. */
pbuf_header_force(p, (s16_t)ip_data.current_ip_header_tot_len);
/* send to upper layers */
LWIP_DEBUGF(IP6_DEBUG, ("ip6_input: \n"));
ip6_debug_print(p);
LWIP_DEBUGF(IP6_DEBUG, ("ip6_input: p->len %"U16_F" p->tot_len %"U16_F"\n", p->len, p->tot_len));
#if LWIP_RAW
/* raw input did not eat the packet? */
if (raw_input(p, inp) == 0)
#endif /* LWIP_RAW */
{
switch (nexth) {
case IP6_NEXTH_NONE:
pbuf_free(p);
break;
#if LWIP_UDP
case IP6_NEXTH_UDP:
#if LWIP_UDPLITE
case IP6_NEXTH_UDPLITE:
#endif /* LWIP_UDPLITE */
/* Point to payload. */
pbuf_header(p, -(s16_t)ip_data.current_ip_header_tot_len);
udp_input(p, inp);
break;
#endif /* LWIP_UDP */
#if LWIP_TCP
case IP6_NEXTH_TCP:
/* Point to payload. */
pbuf_header(p, -(s16_t)ip_data.current_ip_header_tot_len);
tcp_input(p, inp);
break;
#endif /* LWIP_TCP */
#if LWIP_ICMP6
case IP6_NEXTH_ICMP6:
/* Point to payload. */
pbuf_header(p, -(s16_t)ip_data.current_ip_header_tot_len);
icmp6_input(p, inp);
break;
#endif /* LWIP_ICMP */
default:
#if LWIP_ICMP6
/* send ICMP parameter problem unless it was a multicast or ICMPv6 */
if ((!ip6_addr_ismulticast(ip6_current_dest_addr())) &&
(IP6H_NEXTH(ip6hdr) != IP6_NEXTH_ICMP6)) {
icmp6_param_problem(p, ICMP6_PP_HEADER, ip_data.current_ip_header_tot_len - hlen);
}
#endif /* LWIP_ICMP */
LWIP_DEBUGF(IP6_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip6_input: Unsupported transport protocol %"U16_F"\n", (u16_t)IP6H_NEXTH(ip6hdr)));
pbuf_free(p);
IP6_STATS_INC(ip6.proterr);
IP6_STATS_INC(ip6.drop);
break;
}
}
ip6_input_cleanup:
ip_data.current_netif = NULL;
ip_data.current_input_netif = NULL;
ip_data.current_ip6_header = NULL;
ip_data.current_ip_header_tot_len = 0;
ip6_addr_set_zero(ip6_current_src_addr());
ip6_addr_set_zero(ip6_current_dest_addr());
return ERR_OK;
}
