o tcpv4: convert /proc/net/tcp to seq_file

net/ipv4/af_inet.c

@@ -1165,7 +1165,8 @@ extern void fib_proc_exit(void);
 extern int  ip_misc_proc_init(void);
 extern int  raw_proc_init(void);
 extern void raw_proc_exit(void);
-extern int  tcp_get_info(char *buffer, char **start, off_t offset, int length);
+extern int  tcp_proc_init(void);
+extern void tcp_proc_exit(void);
 extern int  udp_proc_init(void);
 extern void udp_proc_exit(void);
 
@@ -1175,7 +1176,7 @@ int __init ipv4_proc_init(void)
 
 	if (raw_proc_init())
 		goto out_raw;
-	if (!proc_net_create("tcp", 0, tcp_get_info))
+	if (tcp_proc_init())
 		goto out_tcp;
 	if (udp_proc_init())
 		goto out_udp;
@@ -1190,7 +1191,7 @@ int __init ipv4_proc_init(void)
 out_fib:
 	udp_proc_exit();
 out_udp:
-	proc_net_remove("tcp");
+	tcp_proc_exit();
 out_tcp:
 	raw_proc_exit();
 out_raw:

net/ipv4/tcp_ipv4.c

@@ -69,6 +69,8 @@
 #include <linux/inet.h>
 #include <linux/ipv6.h>
 #include <linux/stddef.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
 
 extern int sysctl_ip_dynaddr;
 extern int sysctl_ip_default_ttl;
@@ -2131,7 +2133,295 @@ static int tcp_v4_destroy_sock(struct sock *sk)
 	return 0;
 }
 
+#ifdef CONFIG_PROC_FS
 /* Proc filesystem TCP sock list dumping. */
+
+enum tcp_seq_states {
+	TCP_SEQ_STATE_LISTENING,
+	TCP_SEQ_STATE_OPENREQ,
+	TCP_SEQ_STATE_ESTABLISHED,
+	TCP_SEQ_STATE_TIME_WAIT,
+};
+
+struct tcp_iter_state {
+	enum tcp_seq_states state;
+	struct sock	   *syn_wait_sk;
+	int		    bucket, sbucket, num, uid;
+};
+
+static void *listening_get_first(struct seq_file *seq)
+{
+	struct tcp_iter_state* st = seq->private;
+	void *rc = NULL;
+
+	for (st->bucket = 0; st->bucket < TCP_LHTABLE_SIZE; ++st->bucket) {
+		struct open_request *req;
+		struct tcp_opt *tp;
+		struct sock *sk = tcp_listening_hash[st->bucket];
+
+		if (!sk)
+			continue;
+		++st->num;
+		if (TCP_INET_FAMILY(sk->family)) {
+			rc = sk;
+			goto out;
+		}
+	       	tp = tcp_sk(sk);
+		read_lock_bh(&tp->syn_wait_lock);
+		if (tp->listen_opt && tp->listen_opt->qlen) {
+			st->uid		= sock_i_uid(sk);
+			st->syn_wait_sk = sk;
+			st->state	= TCP_SEQ_STATE_OPENREQ;
+			for (st->sbucket = 0; st->sbucket < TCP_SYNQ_HSIZE;
+			     ++st->sbucket) {
+				for (req = tp->listen_opt->syn_table[st->sbucket];
+				     req; req = req->dl_next, ++st->num) {
+					if (!TCP_INET_FAMILY(req->class->family))
+						continue;
+					rc = req;
+					goto out;
+				}
+			}
+			st->state = TCP_SEQ_STATE_LISTENING;
+		}
+		read_unlock_bh(&tp->syn_wait_lock);
+	}
+out:
+	return rc;
+}
+
+static void *listening_get_next(struct seq_file *seq, void *cur)
+{
+	struct tcp_opt *tp;
+	struct sock *sk = cur;
+	struct tcp_iter_state* st = seq->private;
+
+	if (st->state == TCP_SEQ_STATE_OPENREQ) {
+		struct open_request *req = cur;
+
+	       	tp = tcp_sk(st->syn_wait_sk);
+		req = req->dl_next;
+		while (1) {
+			while (req) {
+				++st->num;
+				if (TCP_INET_FAMILY(req->class->family)) {
+					cur = req;
+					goto out;
+				}
+				req = req->dl_next;
+			}
+			if (++st->sbucket >= TCP_SYNQ_HSIZE)
+				break;
+get_req:
+			req = tp->listen_opt->syn_table[st->sbucket];
+		}
+		sk	  = st->syn_wait_sk->next;
+		st->state = TCP_SEQ_STATE_LISTENING;
+		read_unlock_bh(&tp->syn_wait_lock);
+	} else
+		sk = sk->next;
+get_sk:
+	while (sk) {
+		if (TCP_INET_FAMILY(sk->family)) {
+			cur = sk;
+			goto out;
+		}
+	       	tp = tcp_sk(sk);
+		read_lock_bh(&tp->syn_wait_lock);
+		if (tp->listen_opt && tp->listen_opt->qlen) {
+			st->uid		= sock_i_uid(sk);
+			st->syn_wait_sk = sk;
+			st->state	= TCP_SEQ_STATE_OPENREQ;
+			st->sbucket	= 0;
+			goto get_req;
+		}
+		read_unlock_bh(&tp->syn_wait_lock);
+	}
+	if (++st->bucket < TCP_LHTABLE_SIZE) {
+		sk = tcp_listening_hash[st->bucket];
+		goto get_sk;
+	}
+	cur = NULL;
+out:
+	return cur;
+}
+
+static void *listening_get_idx(struct seq_file *seq, loff_t *pos)
+{
+	void *rc = listening_get_first(seq);
+
+	if (rc)
+		while (*pos && (rc = listening_get_next(seq, rc)))
+			--*pos;
+	return *pos ? NULL : rc;
+}
+
+static void *established_get_first(struct seq_file *seq)
+{
+	struct tcp_iter_state* st = seq->private;
+	void *rc = NULL;
+
+	for (st->bucket = 0; st->bucket < tcp_ehash_size; ++st->bucket) {
+		struct sock *sk;
+		struct tcp_tw_bucket *tw;
+	       
+		read_lock(&tcp_ehash[st->bucket].lock);
+		for (sk = tcp_ehash[st->bucket].chain; sk;
+		     sk = sk->next, ++st->num) {
+			if (!TCP_INET_FAMILY(sk->family))
+				continue;
+			rc = sk;
+			goto out;
+		}
+		st->state = TCP_SEQ_STATE_TIME_WAIT;
+		for (tw = (struct tcp_tw_bucket *)
+				tcp_ehash[st->bucket + tcp_ehash_size].chain;
+		     tw; tw = (struct tcp_tw_bucket *)tw->next, ++st->num) {
+			if (!TCP_INET_FAMILY(tw->family))
+				continue;
+			rc = tw;
+			goto out;
+		}
+		read_unlock(&tcp_ehash[st->bucket].lock);
+		st->state = TCP_SEQ_STATE_ESTABLISHED;
+	}
+out:
+	return rc;
+}
+
+static void *established_get_next(struct seq_file *seq, void *cur)
+{
+	struct sock *sk = cur;
+	struct tcp_tw_bucket *tw;
+	struct tcp_iter_state* st = seq->private;
+
+	if (st->state == TCP_SEQ_STATE_TIME_WAIT) {
+		tw = cur;
+		tw = (struct tcp_tw_bucket *)tw->next;
+get_tw:
+		while (tw && !TCP_INET_FAMILY(tw->family)) {
+			++st->num;
+			tw = (struct tcp_tw_bucket *)tw->next;
+		}
+		if (tw) {
+			cur = tw;
+			goto out;
+		}
+		read_unlock(&tcp_ehash[st->bucket].lock);
+		st->state = TCP_SEQ_STATE_ESTABLISHED;
+		if (++st->bucket < tcp_ehash_size) {
+			read_lock(&tcp_ehash[st->bucket].lock);
+			sk = tcp_ehash[st->bucket].chain;
+		} else {
+			cur = NULL;
+			goto out;
+		}
+	} else
+		sk = sk->next;
+
+	while (sk && !TCP_INET_FAMILY(sk->family)) {
+		++st->num;
+		sk = sk->next;
+	}
+	if (!sk) {
+		st->state = TCP_SEQ_STATE_TIME_WAIT;
+		tw = (struct tcp_tw_bucket *)
+				tcp_ehash[st->bucket + tcp_ehash_size].chain;
+		goto get_tw;
+	}
+	cur = sk;
+out:
+	return cur;
+}
+
+static void *established_get_idx(struct seq_file *seq, loff_t pos)
+{
+	void *rc = established_get_first(seq);
+
+	if (rc)
+		while (pos && (rc = established_get_next(seq, rc)))
+			--pos;
+	return pos ? NULL : rc;
+}
+
+static void *tcp_get_idx(struct seq_file *seq, loff_t pos)
+{
+	void *rc;
+	struct tcp_iter_state* st = seq->private;
+
+	tcp_listen_lock();
+	st->state = TCP_SEQ_STATE_LISTENING;
+	rc	  = listening_get_idx(seq, &pos);
+
+	if (!rc) {
+		tcp_listen_unlock();
+		local_bh_disable();
+		st->state = TCP_SEQ_STATE_ESTABLISHED;
+		rc	  = established_get_idx(seq, pos);
+	}
+
+	return rc;
+}
+
+static void *tcp_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	return *pos ? tcp_get_idx(seq, *pos - 1) : (void *)1;
+}
+
+static void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	void *rc = NULL;
+	struct tcp_iter_state* st;
+
+	if (v == (void *)1) {
+		rc = tcp_get_idx(seq, 0);
+		goto out;
+	}
+	st = seq->private;
+
+	switch (st->state) {
+	case TCP_SEQ_STATE_OPENREQ:
+	case TCP_SEQ_STATE_LISTENING:
+		rc = listening_get_next(seq, v);
+		if (!rc) {
+			tcp_listen_unlock();
+			local_bh_disable();
+			st->state = TCP_SEQ_STATE_ESTABLISHED;
+			rc	  = established_get_first(seq);
+		}
+		break;
+	case TCP_SEQ_STATE_ESTABLISHED:
+	case TCP_SEQ_STATE_TIME_WAIT:
+		rc = established_get_next(seq, v);
+		break;
+	}
+out:
+	++*pos;
+	return rc;
+}
+
+static void tcp_seq_stop(struct seq_file *seq, void *v)
+{
+	struct tcp_iter_state* st = seq->private;
+
+	switch (st->state) {
+	case TCP_SEQ_STATE_OPENREQ:
+		if (v) {
+			struct tcp_opt *tp = tcp_sk(st->syn_wait_sk);
+			read_unlock_bh(&tp->syn_wait_lock);
+		}
+	case TCP_SEQ_STATE_LISTENING:
+		tcp_listen_unlock();
+		break;
+	case TCP_SEQ_STATE_TIME_WAIT:
+	case TCP_SEQ_STATE_ESTABLISHED:
+		if (v)
+			read_unlock(&tcp_ehash[st->bucket].lock);
+		local_bh_enable();
+		break;
+	}
+}
+
 static void get_openreq(struct sock *sk, struct open_request *req,
 			char *tmpbuf, int i, int uid)
 {
@@ -2219,137 +2509,89 @@ static void get_timewait_sock(struct tcp_tw_bucket *tw, char *tmpbuf, int i)
 
 #define TMPSZ 150
 
-int tcp_get_info(char *buffer, char **start, off_t offset, int length)
+static int tcp_seq_show(struct seq_file *seq, void *v)
 {
-	int len = 0, num = 0, i;
-	off_t begin, pos = 0;
+	struct tcp_iter_state* st;
 	char tmpbuf[TMPSZ + 1];
 
-	if (offset < TMPSZ)
-		len += sprintf(buffer, "%-*s\n", TMPSZ - 1,
-			       "  sl  local_address rem_address   st tx_queue "
-			       "rx_queue tr tm->when retrnsmt   uid  timeout "
-			       "inode");
-
-	pos = TMPSZ;
-
-	/* First, walk listening socket table. */
-	tcp_listen_lock();
-	for (i = 0; i < TCP_LHTABLE_SIZE; i++) {
-		struct sock *sk;
-		struct tcp_listen_opt *lopt;
-		int k;
-
-		for (sk = tcp_listening_hash[i]; sk; sk = sk->next, num++) {
-			struct open_request *req;
-			int uid;
-			struct tcp_opt *tp = tcp_sk(sk);
-
-			if (!TCP_INET_FAMILY(sk->family))
-				goto skip_listen;
-
-			pos += TMPSZ;
-			if (pos >= offset) {
-				get_tcp_sock(sk, tmpbuf, num);
-				len += sprintf(buffer + len, "%-*s\n",
-					       TMPSZ - 1, tmpbuf);
-				if (pos >= offset + length) {
-					tcp_listen_unlock();
-					goto out_no_bh;
-				}
-			}
-
-skip_listen:
-			uid = sock_i_uid(sk);
-			read_lock_bh(&tp->syn_wait_lock);
-			lopt = tp->listen_opt;
-			if (lopt && lopt->qlen) {
-				for (k = 0; k < TCP_SYNQ_HSIZE; k++) {
-					for (req = lopt->syn_table[k];
-					     req; req = req->dl_next, num++) {
-						if (!TCP_INET_FAMILY(req->class->family))
-							continue;
-
-						pos += TMPSZ;
-						if (pos <= offset)
-							continue;
-						get_openreq(sk, req, tmpbuf,
-							    num, uid);
-						len += sprintf(buffer + len,
-							       "%-*s\n",
-							       TMPSZ - 1,
-							       tmpbuf);
-						if (pos >= offset + length) {
-							read_unlock_bh(&tp->syn_wait_lock);
-							tcp_listen_unlock();
-							goto out_no_bh;
-						}
-					}
-				}
-			}
-			read_unlock_bh(&tp->syn_wait_lock);
-
-			/* Completed requests are in normal socket hash table */
-		}
+	if (v == (void *)1) {
+		seq_printf(seq, "%-*s\n", TMPSZ - 1,
+			   "  sl  local_address rem_address   st tx_queue "
+			   "rx_queue tr tm->when retrnsmt   uid  timeout "
+			   "inode");
+		goto out;
 	}
-	tcp_listen_unlock();
+	st = seq->private;
 
-	local_bh_disable();
+	switch (st->state) {
+	case TCP_SEQ_STATE_LISTENING:
+	case TCP_SEQ_STATE_ESTABLISHED:
+		get_tcp_sock(v, tmpbuf, st->num);
+		break;
+	case TCP_SEQ_STATE_OPENREQ:
+		get_openreq(st->syn_wait_sk, v, tmpbuf, st->num, st->uid);
+		break;
+	case TCP_SEQ_STATE_TIME_WAIT:
+		get_timewait_sock(v, tmpbuf, st->num);
+		break;
+	}
+	seq_printf(seq, "%-*s\n", TMPSZ - 1, tmpbuf);
+out:
+	return 0;
+}
 
-	/* Next, walk established hash chain. */
-	for (i = 0; i < tcp_ehash_size; i++) {
-		struct tcp_ehash_bucket *head = &tcp_ehash[i];
-		struct sock *sk;
-		struct tcp_tw_bucket *tw;
+static struct seq_operations tcp_seq_ops = {
+	.start  = tcp_seq_start,
+	.next   = tcp_seq_next,
+	.stop   = tcp_seq_stop,
+	.show   = tcp_seq_show,
+};
 
-		read_lock(&head->lock);
-		for (sk = head->chain; sk; sk = sk->next, num++) {
-			if (!TCP_INET_FAMILY(sk->family))
-				continue;
-			pos += TMPSZ;
-			if (pos <= offset)
-				continue;
-			get_tcp_sock(sk, tmpbuf, num);
-			len += sprintf(buffer + len, "%-*s\n",
-				       TMPSZ - 1, tmpbuf);
-			if (pos >= offset + length) {
-				read_unlock(&head->lock);
-				goto out;
-			}
-		}
-		for (tw = (struct tcp_tw_bucket *)tcp_ehash[i +
-							  tcp_ehash_size].chain;
-		     tw;
-		     tw = (struct tcp_tw_bucket *)tw->next, num++) {
-			if (!TCP_INET_FAMILY(tw->family))
-				continue;
-			pos += TMPSZ;
-			if (pos <= offset)
-				continue;
-			get_timewait_sock(tw, tmpbuf, num);
-			len += sprintf(buffer + len, "%-*s\n",
-				       TMPSZ - 1, tmpbuf);
-			if (pos >= offset + length) {
-				read_unlock(&head->lock);
-				goto out;
-			}
-		}
-		read_unlock(&head->lock);
-	}
+static int tcp_seq_open(struct inode *inode, struct file *file)
+{
+	struct seq_file *seq;
+	int rc = -ENOMEM;
+	struct tcp_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL);
 
+	if (!s)
+		goto out;
+	rc = seq_open(file, &tcp_seq_ops);
+	if (rc)
+		goto out_kfree;
+	seq	     = file->private_data;
+	seq->private = s;
+	memset(s, 0, sizeof(*s));
 out:
-	local_bh_enable();
-out_no_bh:
+	return rc;
+out_kfree:
+	kfree(s);
+	goto out;
+}
+
+static struct file_operations tcp_seq_fops = {
+	.open           = tcp_seq_open,
+	.read           = seq_read,
+	.llseek         = seq_lseek,
+	.release	= ip_seq_release,
+};
 
-	begin = len - (pos - offset);
-	*start = buffer + begin;
-	len -= begin;
-	if (len > length)
-		len = length;
-	if (len < 0)
-		len = 0;
-	return len;
+int __init tcp_proc_init(void)
+{
+	int rc = 0;
+	struct proc_dir_entry *p = create_proc_entry("tcp", S_IRUGO, proc_net);
+
+	if (p)
+		p->proc_fops = &tcp_seq_fops;
+	else
+		rc = -ENOMEM;
+	return rc;
+}
+
+void __init tcp_proc_exit(void)
+{
+	remove_proc_entry("tcp", proc_net);
 }
+#endif /* CONFIG_PROC_FS */
 
 struct proto tcp_prot = {
 	.name =		"TCP",