linux/net/kcm/kcmproc.c
Tom Herbert 7ced95ef52 kcm: Add memory limit for receive message construction
Message assembly is performed on the TCP socket. This is logically
equivalent of an application that performs a peek on the socket to find
out how much memory is needed for a receive buffer. The receive socket
buffer also provides the maximum message size which is checked.

The receive algorithm is something like:

   1) Receive the first skbuf for a message (or skbufs if multiple are
      needed to determine message length).
   2) Check the message length against the number of bytes in the TCP
      receive queue (tcp_inq()).
	- If all the bytes of the message are in the queue (incluing the
	  skbuf received), then proceed with message assembly (it should
	  complete with the tcp_read_sock)
        - Else, mark the psock with the number of bytes needed to
	  complete the message.
   3) In TCP data ready function, if the psock indicates that we are
      waiting for the rest of the bytes of a messages, check the number
      of queued bytes against that.
        - If there are still not enough bytes for the message, just
	  return
        - Else, clear the waiting bytes and proceed to receive the
	  skbufs.  The message should now be received in one
	  tcp_read_sock

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-09 16:36:15 -05:00

425 lines
9.2 KiB
C

#include <linux/in.h>
#include <linux/inet.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/net.h>
#include <linux/proc_fs.h>
#include <linux/rculist.h>
#include <linux/seq_file.h>
#include <linux/socket.h>
#include <net/inet_sock.h>
#include <net/kcm.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <net/tcp.h>
#ifdef CONFIG_PROC_FS
struct kcm_seq_muxinfo {
char *name;
const struct file_operations *seq_fops;
const struct seq_operations seq_ops;
};
static struct kcm_mux *kcm_get_first(struct seq_file *seq)
{
struct net *net = seq_file_net(seq);
struct kcm_net *knet = net_generic(net, kcm_net_id);
return list_first_or_null_rcu(&knet->mux_list,
struct kcm_mux, kcm_mux_list);
}
static struct kcm_mux *kcm_get_next(struct kcm_mux *mux)
{
struct kcm_net *knet = mux->knet;
return list_next_or_null_rcu(&knet->mux_list, &mux->kcm_mux_list,
struct kcm_mux, kcm_mux_list);
}
static struct kcm_mux *kcm_get_idx(struct seq_file *seq, loff_t pos)
{
struct net *net = seq_file_net(seq);
struct kcm_net *knet = net_generic(net, kcm_net_id);
struct kcm_mux *m;
list_for_each_entry_rcu(m, &knet->mux_list, kcm_mux_list) {
if (!pos)
return m;
--pos;
}
return NULL;
}
static void *kcm_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
void *p;
if (v == SEQ_START_TOKEN)
p = kcm_get_first(seq);
else
p = kcm_get_next(v);
++*pos;
return p;
}
static void *kcm_seq_start(struct seq_file *seq, loff_t *pos)
__acquires(rcu)
{
rcu_read_lock();
if (!*pos)
return SEQ_START_TOKEN;
else
return kcm_get_idx(seq, *pos - 1);
}
static void kcm_seq_stop(struct seq_file *seq, void *v)
__releases(rcu)
{
rcu_read_unlock();
}
struct kcm_proc_mux_state {
struct seq_net_private p;
int idx;
};
static int kcm_seq_open(struct inode *inode, struct file *file)
{
struct kcm_seq_muxinfo *muxinfo = PDE_DATA(inode);
int err;
err = seq_open_net(inode, file, &muxinfo->seq_ops,
sizeof(struct kcm_proc_mux_state));
if (err < 0)
return err;
return err;
}
static void kcm_format_mux_header(struct seq_file *seq)
{
struct net *net = seq_file_net(seq);
struct kcm_net *knet = net_generic(net, kcm_net_id);
seq_printf(seq,
"*** KCM statistics (%d MUX) ****\n",
knet->count);
seq_printf(seq,
"%-14s %-10s %-16s %-10s %-16s %-8s %-8s %-8s %-8s %s",
"Object",
"RX-Msgs",
"RX-Bytes",
"TX-Msgs",
"TX-Bytes",
"Recv-Q",
"Rmem",
"Send-Q",
"Smem",
"Status");
/* XXX: pdsts header stuff here */
seq_puts(seq, "\n");
}
static void kcm_format_sock(struct kcm_sock *kcm, struct seq_file *seq,
int i, int *len)
{
seq_printf(seq,
" kcm-%-7u %-10llu %-16llu %-10llu %-16llu %-8d %-8d %-8d %-8s ",
kcm->index,
kcm->stats.rx_msgs,
kcm->stats.rx_bytes,
kcm->stats.tx_msgs,
kcm->stats.tx_bytes,
kcm->sk.sk_receive_queue.qlen,
sk_rmem_alloc_get(&kcm->sk),
kcm->sk.sk_write_queue.qlen,
"-");
if (kcm->tx_psock)
seq_printf(seq, "Psck-%u ", kcm->tx_psock->index);
if (kcm->tx_wait)
seq_puts(seq, "TxWait ");
if (kcm->tx_wait_more)
seq_puts(seq, "WMore ");
if (kcm->rx_wait)
seq_puts(seq, "RxWait ");
seq_puts(seq, "\n");
}
static void kcm_format_psock(struct kcm_psock *psock, struct seq_file *seq,
int i, int *len)
{
seq_printf(seq,
" psock-%-5u %-10llu %-16llu %-10llu %-16llu %-8d %-8d %-8d %-8d ",
psock->index,
psock->stats.rx_msgs,
psock->stats.rx_bytes,
psock->stats.tx_msgs,
psock->stats.tx_bytes,
psock->sk->sk_receive_queue.qlen,
atomic_read(&psock->sk->sk_rmem_alloc),
psock->sk->sk_write_queue.qlen,
atomic_read(&psock->sk->sk_wmem_alloc));
if (psock->done)
seq_puts(seq, "Done ");
if (psock->tx_stopped)
seq_puts(seq, "TxStop ");
if (psock->rx_stopped)
seq_puts(seq, "RxStop ");
if (psock->tx_kcm)
seq_printf(seq, "Rsvd-%d ", psock->tx_kcm->index);
if (psock->ready_rx_msg)
seq_puts(seq, "RdyRx ");
seq_puts(seq, "\n");
}
static void
kcm_format_mux(struct kcm_mux *mux, loff_t idx, struct seq_file *seq)
{
int i, len;
struct kcm_sock *kcm;
struct kcm_psock *psock;
/* mux information */
seq_printf(seq,
"%-6s%-8s %-10llu %-16llu %-10llu %-16llu %-8s %-8s %-8s %-8s ",
"mux", "",
mux->stats.rx_msgs,
mux->stats.rx_bytes,
mux->stats.tx_msgs,
mux->stats.tx_bytes,
"-", "-", "-", "-");
seq_printf(seq, "KCMs: %d, Psocks %d\n",
mux->kcm_socks_cnt, mux->psocks_cnt);
/* kcm sock information */
i = 0;
spin_lock_bh(&mux->lock);
list_for_each_entry(kcm, &mux->kcm_socks, kcm_sock_list) {
kcm_format_sock(kcm, seq, i, &len);
i++;
}
i = 0;
list_for_each_entry(psock, &mux->psocks, psock_list) {
kcm_format_psock(psock, seq, i, &len);
i++;
}
spin_unlock_bh(&mux->lock);
}
static int kcm_seq_show(struct seq_file *seq, void *v)
{
struct kcm_proc_mux_state *mux_state;
mux_state = seq->private;
if (v == SEQ_START_TOKEN) {
mux_state->idx = 0;
kcm_format_mux_header(seq);
} else {
kcm_format_mux(v, mux_state->idx, seq);
mux_state->idx++;
}
return 0;
}
static const struct file_operations kcm_seq_fops = {
.owner = THIS_MODULE,
.open = kcm_seq_open,
.read = seq_read,
.llseek = seq_lseek,
};
static struct kcm_seq_muxinfo kcm_seq_muxinfo = {
.name = "kcm",
.seq_fops = &kcm_seq_fops,
.seq_ops = {
.show = kcm_seq_show,
.start = kcm_seq_start,
.next = kcm_seq_next,
.stop = kcm_seq_stop,
}
};
static int kcm_proc_register(struct net *net, struct kcm_seq_muxinfo *muxinfo)
{
struct proc_dir_entry *p;
int rc = 0;
p = proc_create_data(muxinfo->name, S_IRUGO, net->proc_net,
muxinfo->seq_fops, muxinfo);
if (!p)
rc = -ENOMEM;
return rc;
}
EXPORT_SYMBOL(kcm_proc_register);
static void kcm_proc_unregister(struct net *net,
struct kcm_seq_muxinfo *muxinfo)
{
remove_proc_entry(muxinfo->name, net->proc_net);
}
EXPORT_SYMBOL(kcm_proc_unregister);
static int kcm_stats_seq_show(struct seq_file *seq, void *v)
{
struct kcm_psock_stats psock_stats;
struct kcm_mux_stats mux_stats;
struct kcm_mux *mux;
struct kcm_psock *psock;
struct net *net = seq->private;
struct kcm_net *knet = net_generic(net, kcm_net_id);
memset(&mux_stats, 0, sizeof(mux_stats));
memset(&psock_stats, 0, sizeof(psock_stats));
mutex_lock(&knet->mutex);
aggregate_mux_stats(&knet->aggregate_mux_stats, &mux_stats);
aggregate_psock_stats(&knet->aggregate_psock_stats,
&psock_stats);
list_for_each_entry_rcu(mux, &knet->mux_list, kcm_mux_list) {
spin_lock_bh(&mux->lock);
aggregate_mux_stats(&mux->stats, &mux_stats);
aggregate_psock_stats(&mux->aggregate_psock_stats,
&psock_stats);
list_for_each_entry(psock, &mux->psocks, psock_list)
aggregate_psock_stats(&psock->stats, &psock_stats);
spin_unlock_bh(&mux->lock);
}
mutex_unlock(&knet->mutex);
seq_printf(seq,
"%-8s %-10s %-16s %-10s %-16s %-10s %-10s %-10s %-10s %-10s\n",
"MUX",
"RX-Msgs",
"RX-Bytes",
"TX-Msgs",
"TX-Bytes",
"TX-Retries",
"Attach",
"Unattach",
"UnattchRsvd",
"RX-RdyDrops");
seq_printf(seq,
"%-8s %-10llu %-16llu %-10llu %-16llu %-10u %-10u %-10u %-10u %-10u\n",
"",
mux_stats.rx_msgs,
mux_stats.rx_bytes,
mux_stats.tx_msgs,
mux_stats.tx_bytes,
mux_stats.tx_retries,
mux_stats.psock_attach,
mux_stats.psock_unattach_rsvd,
mux_stats.psock_unattach,
mux_stats.rx_ready_drops);
seq_printf(seq,
"%-8s %-10s %-16s %-10s %-16s %-10s %-10s %-10s %-10s %-10s %-10s %-10s %-10s\n",
"Psock",
"RX-Msgs",
"RX-Bytes",
"TX-Msgs",
"TX-Bytes",
"Reserved",
"Unreserved",
"RX-Aborts",
"RX-MemFail",
"RX-NeedMor",
"RX-BadLen",
"RX-TooBig",
"TX-Aborts");
seq_printf(seq,
"%-8s %-10llu %-16llu %-10llu %-16llu %-10llu %-10llu %-10u %-10u %-10u %-10u %-10u %-10u\n",
"",
psock_stats.rx_msgs,
psock_stats.rx_bytes,
psock_stats.tx_msgs,
psock_stats.tx_bytes,
psock_stats.reserved,
psock_stats.unreserved,
psock_stats.rx_aborts,
psock_stats.rx_mem_fail,
psock_stats.rx_need_more_hdr,
psock_stats.rx_bad_hdr_len,
psock_stats.rx_msg_too_big,
psock_stats.tx_aborts);
return 0;
}
static int kcm_stats_seq_open(struct inode *inode, struct file *file)
{
return single_open_net(inode, file, kcm_stats_seq_show);
}
static const struct file_operations kcm_stats_seq_fops = {
.owner = THIS_MODULE,
.open = kcm_stats_seq_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release_net,
};
static int kcm_proc_init_net(struct net *net)
{
int err;
if (!proc_create("kcm_stats", S_IRUGO, net->proc_net,
&kcm_stats_seq_fops)) {
err = -ENOMEM;
goto out_kcm_stats;
}
err = kcm_proc_register(net, &kcm_seq_muxinfo);
if (err)
goto out_kcm;
return 0;
out_kcm:
remove_proc_entry("kcm_stats", net->proc_net);
out_kcm_stats:
return err;
}
static void kcm_proc_exit_net(struct net *net)
{
kcm_proc_unregister(net, &kcm_seq_muxinfo);
remove_proc_entry("kcm_stats", net->proc_net);
}
static struct pernet_operations kcm_net_ops = {
.init = kcm_proc_init_net,
.exit = kcm_proc_exit_net,
};
int __init kcm_proc_init(void)
{
return register_pernet_subsys(&kcm_net_ops);
}
void __exit kcm_proc_exit(void)
{
unregister_pernet_subsys(&kcm_net_ops);
}
#endif /* CONFIG_PROC_FS */