static void send_packet(void)
{
if (!buf)
buf = xmalloc(size + ICMP_HRD_SZ);
struct icmp *icmphdr = (struct icmp *)buf;
static int first = 1;
if (first) {
printf("PING "IPFMT" %d(%d) bytes of data\n",
ipfmt(ipaddr),
size,
size + ICMP_HRD_SZ + IP_HRD_SZ);
first = 0;
}
/* fill icmp data */
memset(icmphdr->icmp_data, 'x', size);
icmphdr->icmp_type = ICMP_T_ECHOREQ;
icmphdr->icmp_code = 0;
icmphdr->icmp_id = _htons(id);
icmphdr->icmp_seq = _htons(seq);
icmphdr->icmp_cksum = 0;
icmphdr->icmp_cksum = icmp_chksum((unsigned short *)icmphdr,
ICMP_HRD_SZ + size);
seq++;
/* socket apis */
_send(sock, buf, ICMP_HRD_SZ + size, &skaddr);
psend++;
}
void icmp_in(struct pkbuf *pkb)
{
struct ip *iphdr = pkb2ip(pkb);
struct icmp *icmphdr = ip2icmp(iphdr);
int icmplen, type;
/* sanity check */
icmplen = ipdlen(iphdr);
icmpdbg("%d bytes", icmplen);
if (icmplen < ICMP_HRD_SZ) {
icmpdbg("icmp header is too small");
goto drop_pkb;
}
if (icmp_chksum((unsigned short *)icmphdr, icmplen) != 0) {
icmpdbg("icmp checksum is error");
goto drop_pkb;
}
type = icmphdr->icmp_type;
if (type > ICMP_T_MAXNUM) {
icmpdbg("unknown icmp type %d code %d",
type, icmphdr->icmp_code);
goto drop_pkb;
}
/* handle icmp type */
icmp_table[type].handler(&icmp_table[type], pkb);
return;
drop_pkb:
free_pkb(pkb);
}
void icmp_send(FAR struct net_driver_s *dev, FAR in_addr_t *destaddr)
{
FAR struct icmp_iphdr_s *picmp = ICMPBUF;
if (dev->d_sndlen > 0)
{
IFF_SET_IPv4(dev->d_flags);
/* The total length to send is the size of the application data plus
* the IP and ICMP headers (and, eventually, the Ethernet header)
*/
dev->d_len = dev->d_sndlen + IPICMP_HDRLEN;
/* The total size of the data (for ICMP checksum calculation) includes
* the size of the ICMP header
*/
dev->d_sndlen += ICMP_HDRLEN;
/* Initialize the IP header. */
picmp->vhl = 0x45;
picmp->tos = 0;
picmp->len[0] = (dev->d_len >> 8);
picmp->len[1] = (dev->d_len & 0xff);
++g_ipid;
picmp->ipid[0] = g_ipid >> 8;
picmp->ipid[1] = g_ipid & 0xff;
picmp->ipoffset[0] = IP_FLAG_DONTFRAG >> 8;
picmp->ipoffset[1] = IP_FLAG_DONTFRAG & 0xff;
picmp->ttl = IP_TTL;
picmp->proto = IP_PROTO_ICMP;
net_ipv4addr_hdrcopy(picmp->srcipaddr, &dev->d_ipaddr);
net_ipv4addr_hdrcopy(picmp->destipaddr, destaddr);
/* Calculate IP checksum. */
picmp->ipchksum = 0;
picmp->ipchksum = ~(ipv4_chksum(dev));
/* Calculate the ICMP checksum. */
picmp->icmpchksum = 0;
picmp->icmpchksum = ~(icmp_chksum(dev, dev->d_sndlen));
if (picmp->icmpchksum == 0)
{
picmp->icmpchksum = 0xffff;
}
nllvdbg("Outgoing ICMP packet length: %d (%d)\n",
dev->d_len, (picmp->len[0] << 8) | picmp->len[1]);
#ifdef CONFIG_NET_STATISTICS
g_netstats.icmp.sent++;
g_netstats.ipv4.sent++;
#endif
}
/* NOTE: icmp dont drop @ipkb */
void icmp_send(unsigned char type, unsigned char code,
unsigned int data, struct pkbuf *pkb_in)
{
struct pkbuf *pkb;
struct ip *iphdr = pkb2ip(pkb_in);
struct icmp *icmphdr;
int paylen = _ntohs(iphdr->ip_len); /* icmp payload length */
if (paylen < iphlen(iphdr) + 8)
return;
/*
* RFC 1812 Section 4.3.2.7 for sanity check
* An ICMP error message MUST NOT be sent as the result of receiving:
* 1. A packet sent as a Link Layer broadcast or multicast
* 2. A packet destined to an IP broadcast or IP multicast address
*[3] A packet whose source address has a network prefix of zero or is an
* invalid source address (as defined in Section [5.3.7])
* 4. Any fragment of a datagram other then the first fragment (i.e., a
* packet for which the fragment offset in the IP header is nonzero).
* 5. An ICMP error message
*/
if (pkb_in->pk_type != PKT_LOCALHOST)
return;
if (MULTICAST(iphdr->ip_dst) || BROADCAST(iphdr->ip_dst))
return;
if (iphdr->ip_fragoff & _htons(IP_FRAG_OFF))
return;
if (icmp_type_error(type) && iphdr->ip_pro == IP_P_ICMP) {
icmphdr = ip2icmp(iphdr);
if (icmphdr->icmp_type > ICMP_T_MAXNUM || icmp_error(icmphdr))
return;
}
/* build icmp packet and send */
/* ip packet size must be smaller than 576 bytes */
if (IP_HRD_SZ + ICMP_HRD_SZ + paylen > 576)
paylen = 576 - IP_HRD_SZ - ICMP_HRD_SZ;
pkb = alloc_pkb(ETH_HRD_SZ + IP_HRD_SZ + ICMP_HRD_SZ + paylen);
icmphdr = (struct icmp *)(pkb2ip(pkb)->ip_data);
icmphdr->icmp_type = type;
icmphdr->icmp_code = code;
icmphdr->icmp_cksum = 0;
icmphdr->icmp_undata = data;
memcpy(icmphdr->icmp_data, (unsigned char *)iphdr, paylen);
icmphdr->icmp_cksum =
icmp_chksum((unsigned short *)icmphdr, ICMP_HRD_SZ + paylen);
icmpdbg("to "IPFMT"(payload %d) [type %d code %d]\n",
ipfmt(iphdr->ip_src), paylen, type, code);
ip_send_info(pkb, 0, IP_HRD_SZ + ICMP_HRD_SZ + paylen,
0, IP_P_ICMP, iphdr->ip_src);
}
static void icmp_echo_request(FAR struct net_driver_s *dev,
FAR in_addr_t *destaddr)
{
FAR struct icmp_iphdr_s *picmp = ICMPBUF;
FAR uint8_t *ptr;
size_t sendlen;
size_t icmplen;
size_t pktlen;
int i;
/* The total length to send is the size of the application data plus the
* IPv4 and ICMP headers (and, eventually, the Ethernet header)
*/
pktlen = IPv4_PAYLOAD_SIZE + IPICMP_HDRLEN;
/* The total size of the data (for ICMP checksum calculation) includes the
* size of the ICMP header
*/
icmplen = IPv4_PAYLOAD_SIZE + ICMP_HDRLEN;
/* Initialize the IP header. */
picmp->vhl = 0x45;
picmp->tos = 0;
picmp->len[0] = (pktlen >> 8);
picmp->len[1] = (pktlen & 0xff);
++g_ipid;
picmp->ipid[0] = g_ipid >> 8;
picmp->ipid[1] = g_ipid & 0xff;
picmp->ipoffset[0] = IP_FLAG_DONTFRAG >> 8;
picmp->ipoffset[1] = IP_FLAG_DONTFRAG & 0xff;
picmp->ttl = IP_TTL;
picmp->proto = IP_PROTO_ICMP;
net_ipv4addr_hdrcopy(picmp->srcipaddr, &dev->d_ipaddr);
net_ipv4addr_hdrcopy(picmp->destipaddr, destaddr);
/* Format the ICMP ECHO request packet */
picmp->type = ICMP_ECHO_REQUEST;
picmp->icode = 0;
picmp->id = htons(pstate->png_id);
picmp->seqno = htons(pstate->png_seqno);
/* Insert some recognizable data into the packet */
for (i = 0, ptr = ICMPDAT; i < ICMP_DATALEN; i++)
{
*ptr++ = i;
}
/* Calculate IP checksum. */
picmp->ipchksum = 0;
picmp->ipchksum = ~(ipv4_chksum(dev));
/* Calculate the ICMP checksum. */
picmp->icmpchksum = 0;
picmp->icmpchksum = ~(icmp_chksum(dev, icmplen));
if (picmp->icmpchksum == 0)
{
picmp->icmpchksum = 0xffff;
}
}
