diff --git a/include/net/tcp.h b/include/net/tcp.h
index a1449144848a..573166484413 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1413,7 +1413,8 @@ struct tcp_iter_state {
sa_family_t family;
enum tcp_seq_states state;
struct sock *syn_wait_sk;
- int bucket, sbucket, num, uid;
+ int bucket, offset, sbucket, num, uid;
+ loff_t last_pos;
};
extern int tcp_proc_register(struct net *net, struct tcp_seq_afinfo *afinfo);
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index acdc4c989853..7f976af27bf0 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1980,6 +1980,11 @@ static inline struct inet_timewait_sock *tw_next(struct inet_timewait_sock *tw)
hlist_nulls_entry(tw->tw_node.next, typeof(*tw), tw_node) : NULL;
}
+/*
+ * Get next listener socket follow cur. If cur is NULL, get first socket
+ * starting from bucket given in st->bucket; when st->bucket is zero the
+ * very first socket in the hash table is returned.
+ */
static void *listening_get_next(struct seq_file *seq, void *cur)
{
struct inet_connection_sock *icsk;
@@ -1990,14 +1995,15 @@ static void *listening_get_next(struct seq_file *seq, void *cur)
struct net *net = seq_file_net(seq);
if (!sk) {
- st->bucket = 0;
- ilb = &tcp_hashinfo.listening_hash[0];
+ ilb = &tcp_hashinfo.listening_hash[st->bucket];
spin_lock_bh(&ilb->lock);
sk = sk_nulls_head(&ilb->head);
+ st->offset = 0;
goto get_sk;
}
ilb = &tcp_hashinfo.listening_hash[st->bucket];
++st->num;
+ ++st->offset;
if (st->state == TCP_SEQ_STATE_OPENREQ) {
struct request_sock *req = cur;
@@ -2012,6 +2018,7 @@ static void *listening_get_next(struct seq_file *seq, void *cur)
}
req = req->dl_next;
}
+ st->offset = 0;
if (++st->sbucket >= icsk->icsk_accept_queue.listen_opt->nr_table_entries)
break;
get_req:
@@ -2047,6 +2054,7 @@ start_req:
read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
}
spin_unlock_bh(&ilb->lock);
+ st->offset = 0;
if (++st->bucket < INET_LHTABLE_SIZE) {
ilb = &tcp_hashinfo.listening_hash[st->bucket];
spin_lock_bh(&ilb->lock);
@@ -2060,7 +2068,12 @@ out:
static void *listening_get_idx(struct seq_file *seq, loff_t *pos)
{
- void *rc = listening_get_next(seq, NULL);
+ struct tcp_iter_state *st = seq->private;
+ void *rc;
+
+ st->bucket = 0;
+ st->offset = 0;
+ rc = listening_get_next(seq, NULL);
while (rc && *pos) {
rc = listening_get_next(seq, rc);
@@ -2075,13 +2088,18 @@ static inline int empty_bucket(struct tcp_iter_state *st)
hlist_nulls_empty(&tcp_hashinfo.ehash[st->bucket].twchain);
}
+/*
+ * Get first established socket starting from bucket given in st->bucket.
+ * If st->bucket is zero, the very first socket in the hash is returned.
+ */
static void *established_get_first(struct seq_file *seq)
{
struct tcp_iter_state *st = seq->private;
struct net *net = seq_file_net(seq);
void *rc = NULL;
- for (st->bucket = 0; st->bucket <= tcp_hashinfo.ehash_mask; ++st->bucket) {
+ st->offset = 0;
+ for (; st->bucket <= tcp_hashinfo.ehash_mask; ++st->bucket) {
struct sock *sk;
struct hlist_nulls_node *node;
struct inet_timewait_sock *tw;
@@ -2126,6 +2144,7 @@ static void *established_get_next(struct seq_file *seq, void *cur)
struct net *net = seq_file_net(seq);
++st->num;
+ ++st->offset;
if (st->state == TCP_SEQ_STATE_TIME_WAIT) {
tw = cur;
@@ -2142,6 +2161,7 @@ get_tw:
st->state = TCP_SEQ_STATE_ESTABLISHED;
/* Look for next non empty bucket */
+ st->offset = 0;
while (++st->bucket <= tcp_hashinfo.ehash_mask &&
empty_bucket(st))
;
@@ -2169,7 +2189,11 @@ out:
static void *established_get_idx(struct seq_file *seq, loff_t pos)
{
- void *rc = established_get_first(seq);
+ struct tcp_iter_state *st = seq->private;
+ void *rc;
+
+ st->bucket = 0;
+ rc = established_get_first(seq);
while (rc && pos) {
rc = established_get_next(seq, rc);
@@ -2194,24 +2218,72 @@ static void *tcp_get_idx(struct seq_file *seq, loff_t pos)
return rc;
}
+static void *tcp_seek_last_pos(struct seq_file *seq)
+{
+ struct tcp_iter_state *st = seq->private;
+ int offset = st->offset;
+ int orig_num = st->num;
+ void *rc = NULL;
+
+ switch (st->state) {
+ case TCP_SEQ_STATE_OPENREQ:
+ case TCP_SEQ_STATE_LISTENING:
+ if (st->bucket >= INET_LHTABLE_SIZE)
+ break;
+ st->state = TCP_SEQ_STATE_LISTENING;
+ rc = listening_get_next(seq, NULL);
+ while (offset-- && rc)
+ rc = listening_get_next(seq, rc);
+ if (rc)
+ break;
+ st->bucket = 0;
+ /* Fallthrough */
+ case TCP_SEQ_STATE_ESTABLISHED:
+ case TCP_SEQ_STATE_TIME_WAIT:
+ st->state = TCP_SEQ_STATE_ESTABLISHED;
+ if (st->bucket > tcp_hashinfo.ehash_mask)
+ break;
+ rc = established_get_first(seq);
+ while (offset-- && rc)
+ rc = established_get_next(seq, rc);
+ }
+
+ st->num = orig_num;
+
+ return rc;
+}
+
static void *tcp_seq_start(struct seq_file *seq, loff_t *pos)
{
struct tcp_iter_state *st = seq->private;
+ void *rc;
+
+ if (*pos && *pos == st->last_pos) {
+ rc = tcp_seek_last_pos(seq);
+ if (rc)
+ goto out;
+ }
+
st->state = TCP_SEQ_STATE_LISTENING;
st->num = 0;
- return *pos ? tcp_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
+ st->bucket = 0;
+ st->offset = 0;
+ rc = *pos ? tcp_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
+
+out:
+ st->last_pos = *pos;
+ return rc;
}
static void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
+ struct tcp_iter_state *st = seq->private;
void *rc = NULL;
- struct tcp_iter_state *st;
if (v == SEQ_START_TOKEN) {
rc = tcp_get_idx(seq, 0);
goto out;
}
- st = seq->private;
switch (st->state) {
case TCP_SEQ_STATE_OPENREQ:
@@ -2219,6 +2291,8 @@ static void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
rc = listening_get_next(seq, v);
if (!rc) {
st->state = TCP_SEQ_STATE_ESTABLISHED;
+ st->bucket = 0;
+ st->offset = 0;
rc = established_get_first(seq);
}
break;
@@ -2229,6 +2303,7 @@ static void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
}
out:
++*pos;
+ st->last_pos = *pos;
return rc;
}
@@ -2267,6 +2342,7 @@ static int tcp_seq_open(struct inode *inode, struct file *file)
s = ((struct seq_file *)file->private_data)->private;
s->family = afinfo->family;
+ s->last_pos = 0;
return 0;
}