C++ sk_next函数代码示例

void raw_icmp_error(struct sk_buff *skb, int protocol, u32 info)
{
	int hash;
	struct sock *raw_sk;
	const struct iphdr *iph;
	struct net *net;

	hash = protocol & (RAW_HTABLE_SIZE - 1);

	read_lock(&raw_v4_hashinfo.lock);
	raw_sk = sk_head(&raw_v4_hashinfo.ht[hash]);
	if (raw_sk != NULL) {
		iph = (const struct iphdr *)skb->data;
		net = dev_net(skb->dev);

		while ((raw_sk = __raw_v4_lookup(net, raw_sk, protocol,
						iph->daddr, iph->saddr,
						skb->dev->ifindex)) != NULL) {
			raw_err(raw_sk, skb, info);
			raw_sk = sk_next(raw_sk);
			iph = (const struct iphdr *)skb->data;
		}
	}
	read_unlock(&raw_v4_hashinfo.lock);
}

/* IP input processing comes here for RAW socket delivery.
 * Caller owns SKB, so we must make clones.
 *
 * RFC 1122: SHOULD pass TOS value up to the transport layer.
 * -> It does. And not only TOS, but all IP header.
 */
void raw_v4_input(struct sk_buff *skb, struct iphdr *iph, int hash)
{
	struct sock *sk;
	struct hlist_head *head;

	read_lock(&raw_v4_lock);
	head = &raw_v4_htable[hash];
	if (hlist_empty(head))
		goto out;
	sk = __raw_v4_lookup(__sk_head(head), iph->protocol,
			     iph->saddr, iph->daddr,
			     skb->dev->ifindex);

	while (sk) {
		if (iph->protocol != IPPROTO_ICMP || !icmp_filter(sk, skb)) {
			struct sk_buff *clone = skb_clone(skb, GFP_ATOMIC);

			/* Not releasing hash table! */
			if (clone)
				raw_rcv(sk, clone);
		}
		sk = __raw_v4_lookup(sk_next(sk), iph->protocol,
				     iph->saddr, iph->daddr,
				     skb->dev->ifindex);
	}
out:
	read_unlock(&raw_v4_lock);
}

/* IP input processing comes here for RAW socket delivery.
 * Caller owns SKB, so we must make clones.
 *
 * RFC 1122: SHOULD pass TOS value up to the transport layer.
 * -> It does. And not only TOS, but all IP header.
 */
static int raw_v4_input(struct sk_buff *skb, const struct iphdr *iph, int hash)
{
	struct sock *sk;
	struct hlist_head *head;
	int delivered = 0;
	struct net *net;

	read_lock(&raw_v4_hashinfo.lock);
	head = &raw_v4_hashinfo.ht[hash];
	if (hlist_empty(head))
		goto out;

	net = dev_net(skb->dev);
	sk = __raw_v4_lookup(net, __sk_head(head), iph->protocol,
			     iph->saddr, iph->daddr,
			     skb->dev->ifindex);

	while (sk) {
		delivered = 1;
		if (iph->protocol != IPPROTO_ICMP || !icmp_filter(sk, skb)) {
			struct sk_buff *clone = skb_clone(skb, GFP_ATOMIC);

			/* Not releasing hash table! */
			if (clone)
				raw_rcv(sk, clone);
		}
		sk = __raw_v4_lookup(net, sk_next(sk), iph->protocol,
				     iph->saddr, iph->daddr,
				     skb->dev->ifindex);
	}
out:
	read_unlock(&raw_v4_hashinfo.lock);
	return delivered;
}

static int __vcc_walk(struct sock **sock, int family, int *bucket, loff_t l)
{
	struct sock *sk = *sock;

	if (sk == SEQ_START_TOKEN) {
		for (*bucket = 0; *bucket < VCC_HTABLE_SIZE; ++*bucket) {
			struct hlist_head *head = &vcc_hash[*bucket];

			sk = hlist_empty(head) ? NULL : __sk_head(head);
			if (sk)
				break;
		}
		l--;
	}
try_again:
	for (; sk; sk = sk_next(sk)) {
		l -= compare_family(sk, family);
		if (l < 0)
			goto out;
	}
	if (!sk && ++*bucket < VCC_HTABLE_SIZE) {
		sk = sk_head(&vcc_hash[*bucket]);
		goto try_again;
	}
	sk = SEQ_START_TOKEN;
out:
	*sock = sk;
	return (l < 0);
}

void raw_icmp_error(struct sk_buff *skb, int protocol, u32 info)
{
	int hash;
	struct sock *raw_sk;
	struct iphdr *iph;
	struct vrf *vrf;

	hash = protocol & (RAW_HTABLE_SIZE - 1);

	read_lock(&raw_v4_hashinfo.lock);
	raw_sk = sk_head(&raw_v4_hashinfo.ht[hash]);
	if (raw_sk != NULL) {
		iph = (struct iphdr *)skb->data;
		vrf = if_dev_vrf(skb->dev);

		while ((raw_sk = __raw_v4_lookup(vrf, skb->litevrf_id, raw_sk, protocol,
						iph->daddr, iph->saddr,
						skb->dev->ifindex,ip_hdr(skb))) != NULL) {
			raw_err(raw_sk, skb, info);
			raw_sk = sk_next(raw_sk);
			iph = (struct iphdr *)skb->data;
		}
	}
	read_unlock(&raw_v4_hashinfo.lock);
}

/* IP input processing comes here for RAW socket delivery.
 * Caller owns SKB, so we must make clones.
 *
 * RFC 1122: SHOULD pass TOS value up to the transport layer.
 * -> It does. And not only TOS, but all IP header.
 */
static int raw_v4_input(struct sk_buff *skb, struct iphdr *iph, int hash)
{
	struct sock *sk;
	struct hlist_head *head;
	int delivered = 0;
	struct net *net;

	read_lock(&raw_v4_hashinfo.lock);
	head = &raw_v4_hashinfo.ht[hash];
	if (hlist_empty(head))
		goto out;
	//head就是指向一个链表...该链表的结点都是protocol相同的struct sock...
	//然后遍历该链表来确定是否有哪个struct sock来处理该数据包啦..
	net = dev_net(skb->dev);
	sk = __raw_v4_lookup(net, __sk_head(head), iph->protocol, iph->saddr, iph->daddr, skb->dev->ifindex);

	while (sk) {
		//来到这里代表至少说有一个struct sock可以处理该数据包....因此设置返回值为1...
		delivered = 1;
		if (iph->protocol != IPPROTO_ICMP || !icmp_filter(sk, skb)) {
			struct sk_buff *clone = skb_clone(skb, GFP_ATOMIC);

			/* Not releasing hash table! */
			if (clone)
				raw_rcv(sk, clone);
		}
		//可能存在多个struct sock同时处理一个数据包啦...主要还是看匹配规则(lookup)..
		//这里看到只是匹配协议/源地址/目的地址.
		sk = __raw_v4_lookup(net, sk_next(sk), iph->protocol, iph->saddr, iph->daddr, skb->dev->ifindex);
	}
out:
	read_unlock(&raw_v4_hashinfo.lock);
	return delivered;
}

static void *atalk_seq_socket_next(struct seq_file *seq, void *v, loff_t *pos)
{
	struct sock *i;

	++*pos;
	if (v == SEQ_START_TOKEN) {
		i = sk_head(&atalk_sockets);
		goto out;
	}
	i = sk_next(v);
out:
	return i;
}

static struct sock *raw_get_next(struct seq_file *seq, struct sock *sk)
{
	struct raw_iter_state *state = raw_seq_private(seq);

	do {
		sk = sk_next(sk);
try_again:
		;
	} while (sk && sock_net(sk) != seq_file_net(seq));

	if (!sk && ++state->bucket < RAW_HTABLE_SIZE) {
		sk = sk_head(&state->h->ht[state->bucket]);
		goto try_again;
	}
	return sk;
}

void raw_icmp_error(struct sk_buff *skb, int protocol, u32 info)
{
	int hash;
	struct sock *raw_sk;
	struct iphdr *iph;

	hash = protocol & (RAWV4_HTABLE_SIZE - 1);

	read_lock(&raw_v4_lock);
	raw_sk = sk_head(&raw_v4_htable[hash]);
	if (raw_sk != NULL) {
		iph = (struct iphdr *)skb->data;
		while ((raw_sk = __raw_v4_lookup(raw_sk, protocol, iph->daddr,
						iph->saddr,
						skb->dev->ifindex)) != NULL) {
			raw_err(raw_sk, skb, info);
			raw_sk = sk_next(raw_sk);
			iph = (struct iphdr *)skb->data;
		}
	}
	read_unlock(&raw_v4_lock);
}