static void igmp_send_report(struct device *dev, unsigned long address, int type)
{
struct sk_buff *skb=alloc_skb(MAX_IGMP_SIZE, GFP_ATOMIC);
int tmp;
struct igmphdr *ih;
if(skb==NULL)
return;
if (type != IGMP_HOST_LEAVE_MESSAGE)
tmp=ip_build_header(skb, dev->pa_addr, address, &dev, IPPROTO_IGMP, NULL,
28 , 0, 1, NULL);
else
tmp=ip_build_header(skb, dev->pa_addr, IGMP_ALL_ROUTER, &dev, IPPROTO_IGMP, NULL,
28, 0, 1, NULL);
if(tmp<0)
{
kfree_skb(skb, FREE_WRITE);
return;
}
ih=(struct igmphdr *)skb_put(skb,sizeof(struct igmphdr));
ih->type=type;
ih->code=0;
ih->csum=0;
ih->group=address;
ih->csum=ip_compute_csum((void *)ih,sizeof(struct igmphdr)); /* Checksum fill */
ip_queue_xmit(NULL,dev,skb,1);
}
/* sends an icmp message in response to a packet. */
void
icmp_reply (struct sk_buff *skb_in, int type, int code, struct device *dev)
{
struct sk_buff *skb;
struct ip_header *iph;
int offset;
struct icmp_header *icmph;
int len;
/* get some memory for the replay. */
len = sizeof (*skb) + 8 /* amount of header to return. */ +
sizeof (struct icmp_header) +
64 /* enough for an ip header. */ +
dev->hard_header_len;
skb = malloc (len);
if (skb == NULL) return;
skb->mem_addr = skb;
skb->mem_len = len;
len -= sizeof (*skb);
/* find the ip header. */
iph = (struct ip_header *)(skb_in+1);
iph = (struct ip_header *)((unsigned char *)iph + dev->hard_header_len);
/* Build Layer 2-3 headers for message back to source */
offset = ip_build_header( skb, iph->daddr, iph->saddr,
&dev, IP_ICMP, NULL, len );
if (offset < 0)
{
skb->sk = NULL;
free_skb (skb, FREE_READ);
return;
}
/* Readjust length according to actual IP header size */
skb->len = offset + sizeof (struct icmp_header) + 8;
icmph = (struct icmp_header *)((unsigned char *)(skb+1) + offset);
icmph->type = type;
icmph->code = code;
icmph->checksum = 0; /* we don't need to compute this. */
icmph->un.gateway = 0; /* might as well 0 it. */
memcpy (icmph+1, iph+1, 8);
/* send it and free it. */
ip_queue_xmit (NULL, dev, skb, 1);
}
static void igmp_send_report(struct device *dev, unsigned long address, int type)
{
struct sk_buff *skb=alloc_skb(MAX_IGMP_SIZE, GFP_ATOMIC);
int tmp;
struct igmphdr *igh;
if(skb==NULL)
return;
tmp=ip_build_header(skb, INADDR_ANY, address, &dev, IPPROTO_IGMP, NULL,
skb->mem_len, 0, 1);
if(tmp<0)
{
kfree_skb(skb, FREE_WRITE);
return;
}
igh=(struct igmphdr *)(skb->data+tmp);
skb->len=tmp+sizeof(*igh);
igh->csum=0;
igh->unused=0;
igh->type=type;
igh->group=address;
igh->csum=ip_compute_csum((void *)igh,sizeof(*igh));
ip_queue_xmit(NULL,dev,skb,1);
}
int
icmp_rcv(struct sk_buff *skb1, struct device *dev, struct options *opt,
unsigned long daddr, unsigned short len,
unsigned long saddr, int redo, struct ip_protocol *protocol )
{
int size, offset;
struct icmp_header *icmph, *icmphr;
struct sk_buff *skb;
unsigned char *buff;
/* drop broadcast packets. */
if ((daddr & 0xff000000) == 0 || (daddr & 0xff000000) == 0xff000000)
{
skb1->sk = NULL;
free_skb (skb1, FREE_READ);
return (0);
}
buff = skb1->h.raw;
icmph = (struct icmp_header *)buff;
/* Validate the packet first */
if( icmph->checksum )
{ /* Checksums Enabled? */
if( ip_compute_csum( (unsigned char *)icmph, len ) )
{
/* Failed checksum! */
PRINTK("\nICMP ECHO failed checksum!");
skb1->sk = NULL;
free_skb (skb1, FREE_READ);
return (0);
}
}
print_icmph(icmph);
/* Parse the ICMP message */
switch( icmph->type )
{
case ICMP_DEST_UNREACH:
case ICMP_SOURCE_QUENCH:
{
struct ip_header *iph;
struct ip_protocol *ipprot;
unsigned char hash;
int err;
err = icmph->type << 8 | icmph->code;
/* we need to cause the socket to be closed and the error message
to be set appropriately. */
iph = (struct ip_header *)(icmph+1);
/* get the protocol(s) */
hash = iph->protocol & (MAX_IP_PROTOS -1 );
for (ipprot = ip_protos[hash]; ipprot != NULL; ipprot=ipprot->next)
{
/* pass it off to everyone who wants it. */
ipprot->err_handler (err, (unsigned char *)iph+4*iph->ihl,
iph->daddr, iph->saddr, ipprot);
}
skb1->sk = NULL;
free_skb (skb1, FREE_READ);
return (0);
}
case ICMP_REDIRECT:
{
/* we need to put a new route in the routing table. */
struct rtable *rt; /* we will add a new route. */
struct ip_header *iph;
iph = (struct ip_header *)(icmph+1);
rt = malloc (sizeof (*rt));
if (rt != NULL)
{
rt->net = iph->daddr;
/* assume class C network. Technically this is incorrect,
but will give it a try. */
if ((icmph->code & 1) == 0) rt->net &= 0x00ffffff;
rt->dev = dev;
rt->router = icmph->un.gateway;
add_route (rt);
}
skb1->sk = NULL;
free_skb (skb1, FREE_READ);
return (0);
}
case ICMP_ECHO:
/* Allocate an sk_buff response buffer (assume 64 byte IP header) */
size = sizeof( struct sk_buff ) + dev->hard_header_len + 64 + len;
skb = malloc( size );
if (skb == NULL)
{
skb1->sk = NULL;
free_skb (skb1, FREE_READ);
return (0);
}
skb->sk = NULL;
skb->mem_addr = skb;
skb->mem_len = size;
/* Build Layer 2-3 headers for message back to source */
offset = ip_build_header( skb, daddr, saddr, &dev, IP_ICMP, opt, len );
if (offset < 0)
{
/* Problems building header */
PRINTK("\nCould not build IP Header for ICMP ECHO Response");
free_s (skb->mem_addr, skb->mem_len);
skb1->sk = NULL;
free_skb (skb1, FREE_READ);
return( 0 ); /* just toss the received packet */
}
/* Readjust length according to actual IP header size */
skb->len = offset + len;
/* Build ICMP_ECHO Response message */
icmphr = (struct icmp_header *)( (char *)( skb + 1 ) + offset );
memcpy( (char *)icmphr, (char *)icmph, len );
icmphr->type = ICMP_ECHOREPLY;
icmphr->code = 0;
icmphr->checksum = 0;
if( icmph->checksum )
{ /* Calculate Checksum */
icmphr->checksum = ip_compute_csum( (void *)icmphr, len );
}
/* Ship it out - free it when done */
ip_queue_xmit( (volatile struct sock *)NULL, dev, skb, 1 );
skb1->sk = NULL;
free_skb (skb1, FREE_READ);
return( 0 );
default:
PRINTK("\nUnsupported ICMP type = x%x", icmph->type );
skb1->sk = NULL;
free_skb (skb1, FREE_READ);
return( 0 ); /* just toss the packet */
}
/* should be unecessary, but just in case. */
skb1->sk = NULL;
free_skb (skb1, FREE_READ);
return( 0 ); /* just toss the packet */
}
