linux/net/sctp/proc.c
Tom Herbert 97a6ec4ac0 rhashtable: Change rhashtable_walk_start to return void
Most callers of rhashtable_walk_start don't care about a resize event
which is indicated by a return value of -EAGAIN. So calls to
rhashtable_walk_start are wrapped wih code to ignore -EAGAIN. Something
like this is common:

       ret = rhashtable_walk_start(rhiter);
       if (ret && ret != -EAGAIN)
               goto out;

Since zero and -EAGAIN are the only possible return values from the
function this check is pointless. The condition never evaluates to true.

This patch changes rhashtable_walk_start to return void. This simplifies
code for the callers that ignore -EAGAIN. For the few cases where the
caller cares about the resize event, particularly where the table can be
walked in mulitple parts for netlink or seq file dump, the function
rhashtable_walk_start_check has been added that returns -EAGAIN on a
resize event.

Signed-off-by: Tom Herbert <tom@quantonium.net>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-11 09:58:38 -05:00

521 lines
14 KiB
C

/* SCTP kernel implementation
* Copyright (c) 2003 International Business Machines, Corp.
*
* This file is part of the SCTP kernel implementation
*
* This SCTP implementation is free software;
* you can redistribute it and/or modify it under the terms of
* the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This SCTP implementation is distributed in the hope that it
* will be useful, but WITHOUT ANY WARRANTY; without even the implied
* ************************
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU CC; see the file COPYING. If not, see
* <http://www.gnu.org/licenses/>.
*
* Please send any bug reports or fixes you make to the
* email address(es):
* lksctp developers <linux-sctp@vger.kernel.org>
*
* Written or modified by:
* Sridhar Samudrala <sri@us.ibm.com>
*/
#include <linux/types.h>
#include <linux/seq_file.h>
#include <linux/init.h>
#include <linux/export.h>
#include <net/sctp/sctp.h>
#include <net/ip.h> /* for snmp_fold_field */
static const struct snmp_mib sctp_snmp_list[] = {
SNMP_MIB_ITEM("SctpCurrEstab", SCTP_MIB_CURRESTAB),
SNMP_MIB_ITEM("SctpActiveEstabs", SCTP_MIB_ACTIVEESTABS),
SNMP_MIB_ITEM("SctpPassiveEstabs", SCTP_MIB_PASSIVEESTABS),
SNMP_MIB_ITEM("SctpAborteds", SCTP_MIB_ABORTEDS),
SNMP_MIB_ITEM("SctpShutdowns", SCTP_MIB_SHUTDOWNS),
SNMP_MIB_ITEM("SctpOutOfBlues", SCTP_MIB_OUTOFBLUES),
SNMP_MIB_ITEM("SctpChecksumErrors", SCTP_MIB_CHECKSUMERRORS),
SNMP_MIB_ITEM("SctpOutCtrlChunks", SCTP_MIB_OUTCTRLCHUNKS),
SNMP_MIB_ITEM("SctpOutOrderChunks", SCTP_MIB_OUTORDERCHUNKS),
SNMP_MIB_ITEM("SctpOutUnorderChunks", SCTP_MIB_OUTUNORDERCHUNKS),
SNMP_MIB_ITEM("SctpInCtrlChunks", SCTP_MIB_INCTRLCHUNKS),
SNMP_MIB_ITEM("SctpInOrderChunks", SCTP_MIB_INORDERCHUNKS),
SNMP_MIB_ITEM("SctpInUnorderChunks", SCTP_MIB_INUNORDERCHUNKS),
SNMP_MIB_ITEM("SctpFragUsrMsgs", SCTP_MIB_FRAGUSRMSGS),
SNMP_MIB_ITEM("SctpReasmUsrMsgs", SCTP_MIB_REASMUSRMSGS),
SNMP_MIB_ITEM("SctpOutSCTPPacks", SCTP_MIB_OUTSCTPPACKS),
SNMP_MIB_ITEM("SctpInSCTPPacks", SCTP_MIB_INSCTPPACKS),
SNMP_MIB_ITEM("SctpT1InitExpireds", SCTP_MIB_T1_INIT_EXPIREDS),
SNMP_MIB_ITEM("SctpT1CookieExpireds", SCTP_MIB_T1_COOKIE_EXPIREDS),
SNMP_MIB_ITEM("SctpT2ShutdownExpireds", SCTP_MIB_T2_SHUTDOWN_EXPIREDS),
SNMP_MIB_ITEM("SctpT3RtxExpireds", SCTP_MIB_T3_RTX_EXPIREDS),
SNMP_MIB_ITEM("SctpT4RtoExpireds", SCTP_MIB_T4_RTO_EXPIREDS),
SNMP_MIB_ITEM("SctpT5ShutdownGuardExpireds", SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS),
SNMP_MIB_ITEM("SctpDelaySackExpireds", SCTP_MIB_DELAY_SACK_EXPIREDS),
SNMP_MIB_ITEM("SctpAutocloseExpireds", SCTP_MIB_AUTOCLOSE_EXPIREDS),
SNMP_MIB_ITEM("SctpT3Retransmits", SCTP_MIB_T3_RETRANSMITS),
SNMP_MIB_ITEM("SctpPmtudRetransmits", SCTP_MIB_PMTUD_RETRANSMITS),
SNMP_MIB_ITEM("SctpFastRetransmits", SCTP_MIB_FAST_RETRANSMITS),
SNMP_MIB_ITEM("SctpInPktSoftirq", SCTP_MIB_IN_PKT_SOFTIRQ),
SNMP_MIB_ITEM("SctpInPktBacklog", SCTP_MIB_IN_PKT_BACKLOG),
SNMP_MIB_ITEM("SctpInPktDiscards", SCTP_MIB_IN_PKT_DISCARDS),
SNMP_MIB_ITEM("SctpInDataChunkDiscards", SCTP_MIB_IN_DATA_CHUNK_DISCARDS),
SNMP_MIB_SENTINEL
};
/* Display sctp snmp mib statistics(/proc/net/sctp/snmp). */
static int sctp_snmp_seq_show(struct seq_file *seq, void *v)
{
unsigned long buff[SCTP_MIB_MAX];
struct net *net = seq->private;
int i;
memset(buff, 0, sizeof(unsigned long) * SCTP_MIB_MAX);
snmp_get_cpu_field_batch(buff, sctp_snmp_list,
net->sctp.sctp_statistics);
for (i = 0; sctp_snmp_list[i].name; i++)
seq_printf(seq, "%-32s\t%ld\n", sctp_snmp_list[i].name,
buff[i]);
return 0;
}
/* Initialize the seq file operations for 'snmp' object. */
static int sctp_snmp_seq_open(struct inode *inode, struct file *file)
{
return single_open_net(inode, file, sctp_snmp_seq_show);
}
static const struct file_operations sctp_snmp_seq_fops = {
.owner = THIS_MODULE,
.open = sctp_snmp_seq_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release_net,
};
/* Set up the proc fs entry for 'snmp' object. */
int __net_init sctp_snmp_proc_init(struct net *net)
{
struct proc_dir_entry *p;
p = proc_create("snmp", S_IRUGO, net->sctp.proc_net_sctp,
&sctp_snmp_seq_fops);
if (!p)
return -ENOMEM;
return 0;
}
/* Cleanup the proc fs entry for 'snmp' object. */
void sctp_snmp_proc_exit(struct net *net)
{
remove_proc_entry("snmp", net->sctp.proc_net_sctp);
}
/* Dump local addresses of an association/endpoint. */
static void sctp_seq_dump_local_addrs(struct seq_file *seq, struct sctp_ep_common *epb)
{
struct sctp_association *asoc;
struct sctp_sockaddr_entry *laddr;
struct sctp_transport *peer;
union sctp_addr *addr, *primary = NULL;
struct sctp_af *af;
if (epb->type == SCTP_EP_TYPE_ASSOCIATION) {
asoc = sctp_assoc(epb);
peer = asoc->peer.primary_path;
if (unlikely(peer == NULL)) {
WARN(1, "Association %p with NULL primary path!\n", asoc);
return;
}
primary = &peer->saddr;
}
rcu_read_lock();
list_for_each_entry_rcu(laddr, &epb->bind_addr.address_list, list) {
if (!laddr->valid)
continue;
addr = &laddr->a;
af = sctp_get_af_specific(addr->sa.sa_family);
if (primary && af->cmp_addr(addr, primary)) {
seq_printf(seq, "*");
}
af->seq_dump_addr(seq, addr);
}
rcu_read_unlock();
}
/* Dump remote addresses of an association. */
static void sctp_seq_dump_remote_addrs(struct seq_file *seq, struct sctp_association *assoc)
{
struct sctp_transport *transport;
union sctp_addr *addr, *primary;
struct sctp_af *af;
primary = &assoc->peer.primary_addr;
list_for_each_entry_rcu(transport, &assoc->peer.transport_addr_list,
transports) {
addr = &transport->ipaddr;
af = sctp_get_af_specific(addr->sa.sa_family);
if (af->cmp_addr(addr, primary)) {
seq_printf(seq, "*");
}
af->seq_dump_addr(seq, addr);
}
}
static void *sctp_eps_seq_start(struct seq_file *seq, loff_t *pos)
{
if (*pos >= sctp_ep_hashsize)
return NULL;
if (*pos < 0)
*pos = 0;
if (*pos == 0)
seq_printf(seq, " ENDPT SOCK STY SST HBKT LPORT UID INODE LADDRS\n");
return (void *)pos;
}
static void sctp_eps_seq_stop(struct seq_file *seq, void *v)
{
}
static void *sctp_eps_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
if (++*pos >= sctp_ep_hashsize)
return NULL;
return pos;
}
/* Display sctp endpoints (/proc/net/sctp/eps). */
static int sctp_eps_seq_show(struct seq_file *seq, void *v)
{
struct sctp_hashbucket *head;
struct sctp_ep_common *epb;
struct sctp_endpoint *ep;
struct sock *sk;
int hash = *(loff_t *)v;
if (hash >= sctp_ep_hashsize)
return -ENOMEM;
head = &sctp_ep_hashtable[hash];
read_lock_bh(&head->lock);
sctp_for_each_hentry(epb, &head->chain) {
ep = sctp_ep(epb);
sk = epb->sk;
if (!net_eq(sock_net(sk), seq_file_net(seq)))
continue;
seq_printf(seq, "%8pK %8pK %-3d %-3d %-4d %-5d %5u %5lu ", ep, sk,
sctp_sk(sk)->type, sk->sk_state, hash,
epb->bind_addr.port,
from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk)),
sock_i_ino(sk));
sctp_seq_dump_local_addrs(seq, epb);
seq_printf(seq, "\n");
}
read_unlock_bh(&head->lock);
return 0;
}
static const struct seq_operations sctp_eps_ops = {
.start = sctp_eps_seq_start,
.next = sctp_eps_seq_next,
.stop = sctp_eps_seq_stop,
.show = sctp_eps_seq_show,
};
/* Initialize the seq file operations for 'eps' object. */
static int sctp_eps_seq_open(struct inode *inode, struct file *file)
{
return seq_open_net(inode, file, &sctp_eps_ops,
sizeof(struct seq_net_private));
}
static const struct file_operations sctp_eps_seq_fops = {
.open = sctp_eps_seq_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_net,
};
/* Set up the proc fs entry for 'eps' object. */
int __net_init sctp_eps_proc_init(struct net *net)
{
struct proc_dir_entry *p;
p = proc_create("eps", S_IRUGO, net->sctp.proc_net_sctp,
&sctp_eps_seq_fops);
if (!p)
return -ENOMEM;
return 0;
}
/* Cleanup the proc fs entry for 'eps' object. */
void sctp_eps_proc_exit(struct net *net)
{
remove_proc_entry("eps", net->sctp.proc_net_sctp);
}
struct sctp_ht_iter {
struct seq_net_private p;
struct rhashtable_iter hti;
int start_fail;
};
static void *sctp_transport_seq_start(struct seq_file *seq, loff_t *pos)
{
struct sctp_ht_iter *iter = seq->private;
sctp_transport_walk_start(&iter->hti);
iter->start_fail = 0;
return sctp_transport_get_idx(seq_file_net(seq), &iter->hti, *pos);
}
static void sctp_transport_seq_stop(struct seq_file *seq, void *v)
{
struct sctp_ht_iter *iter = seq->private;
if (iter->start_fail)
return;
sctp_transport_walk_stop(&iter->hti);
}
static void *sctp_transport_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
struct sctp_ht_iter *iter = seq->private;
++*pos;
return sctp_transport_get_next(seq_file_net(seq), &iter->hti);
}
/* Display sctp associations (/proc/net/sctp/assocs). */
static int sctp_assocs_seq_show(struct seq_file *seq, void *v)
{
struct sctp_transport *transport;
struct sctp_association *assoc;
struct sctp_ep_common *epb;
struct sock *sk;
if (v == SEQ_START_TOKEN) {
seq_printf(seq, " ASSOC SOCK STY SST ST HBKT "
"ASSOC-ID TX_QUEUE RX_QUEUE UID INODE LPORT "
"RPORT LADDRS <-> RADDRS "
"HBINT INS OUTS MAXRT T1X T2X RTXC "
"wmema wmemq sndbuf rcvbuf\n");
return 0;
}
transport = (struct sctp_transport *)v;
if (!sctp_transport_hold(transport))
return 0;
assoc = transport->asoc;
epb = &assoc->base;
sk = epb->sk;
seq_printf(seq,
"%8pK %8pK %-3d %-3d %-2d %-4d "
"%4d %8d %8d %7u %5lu %-5d %5d ",
assoc, sk, sctp_sk(sk)->type, sk->sk_state,
assoc->state, 0,
assoc->assoc_id,
assoc->sndbuf_used,
atomic_read(&assoc->rmem_alloc),
from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk)),
sock_i_ino(sk),
epb->bind_addr.port,
assoc->peer.port);
seq_printf(seq, " ");
sctp_seq_dump_local_addrs(seq, epb);
seq_printf(seq, "<-> ");
sctp_seq_dump_remote_addrs(seq, assoc);
seq_printf(seq, "\t%8lu %5d %5d %4d %4d %4d %8d "
"%8d %8d %8d %8d",
assoc->hbinterval, assoc->stream.incnt,
assoc->stream.outcnt, assoc->max_retrans,
assoc->init_retries, assoc->shutdown_retries,
assoc->rtx_data_chunks,
refcount_read(&sk->sk_wmem_alloc),
sk->sk_wmem_queued,
sk->sk_sndbuf,
sk->sk_rcvbuf);
seq_printf(seq, "\n");
sctp_transport_put(transport);
return 0;
}
static const struct seq_operations sctp_assoc_ops = {
.start = sctp_transport_seq_start,
.next = sctp_transport_seq_next,
.stop = sctp_transport_seq_stop,
.show = sctp_assocs_seq_show,
};
/* Initialize the seq file operations for 'assocs' object. */
static int sctp_assocs_seq_open(struct inode *inode, struct file *file)
{
return seq_open_net(inode, file, &sctp_assoc_ops,
sizeof(struct sctp_ht_iter));
}
static const struct file_operations sctp_assocs_seq_fops = {
.open = sctp_assocs_seq_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_net,
};
/* Set up the proc fs entry for 'assocs' object. */
int __net_init sctp_assocs_proc_init(struct net *net)
{
struct proc_dir_entry *p;
p = proc_create("assocs", S_IRUGO, net->sctp.proc_net_sctp,
&sctp_assocs_seq_fops);
if (!p)
return -ENOMEM;
return 0;
}
/* Cleanup the proc fs entry for 'assocs' object. */
void sctp_assocs_proc_exit(struct net *net)
{
remove_proc_entry("assocs", net->sctp.proc_net_sctp);
}
static int sctp_remaddr_seq_show(struct seq_file *seq, void *v)
{
struct sctp_association *assoc;
struct sctp_transport *transport, *tsp;
if (v == SEQ_START_TOKEN) {
seq_printf(seq, "ADDR ASSOC_ID HB_ACT RTO MAX_PATH_RTX "
"REM_ADDR_RTX START STATE\n");
return 0;
}
transport = (struct sctp_transport *)v;
if (!sctp_transport_hold(transport))
return 0;
assoc = transport->asoc;
list_for_each_entry_rcu(tsp, &assoc->peer.transport_addr_list,
transports) {
/*
* The remote address (ADDR)
*/
tsp->af_specific->seq_dump_addr(seq, &tsp->ipaddr);
seq_printf(seq, " ");
/*
* The association ID (ASSOC_ID)
*/
seq_printf(seq, "%d ", tsp->asoc->assoc_id);
/*
* If the Heartbeat is active (HB_ACT)
* Note: 1 = Active, 0 = Inactive
*/
seq_printf(seq, "%d ", timer_pending(&tsp->hb_timer));
/*
* Retransmit time out (RTO)
*/
seq_printf(seq, "%lu ", tsp->rto);
/*
* Maximum path retransmit count (PATH_MAX_RTX)
*/
seq_printf(seq, "%d ", tsp->pathmaxrxt);
/*
* remote address retransmit count (REM_ADDR_RTX)
* Note: We don't have a way to tally this at the moment
* so lets just leave it as zero for the moment
*/
seq_puts(seq, "0 ");
/*
* remote address start time (START). This is also not
* currently implemented, but we can record it with a
* jiffies marker in a subsequent patch
*/
seq_puts(seq, "0 ");
/*
* The current state of this destination. I.e.
* SCTP_ACTIVE, SCTP_INACTIVE, ...
*/
seq_printf(seq, "%d", tsp->state);
seq_printf(seq, "\n");
}
sctp_transport_put(transport);
return 0;
}
static const struct seq_operations sctp_remaddr_ops = {
.start = sctp_transport_seq_start,
.next = sctp_transport_seq_next,
.stop = sctp_transport_seq_stop,
.show = sctp_remaddr_seq_show,
};
/* Cleanup the proc fs entry for 'remaddr' object. */
void sctp_remaddr_proc_exit(struct net *net)
{
remove_proc_entry("remaddr", net->sctp.proc_net_sctp);
}
static int sctp_remaddr_seq_open(struct inode *inode, struct file *file)
{
return seq_open_net(inode, file, &sctp_remaddr_ops,
sizeof(struct sctp_ht_iter));
}
static const struct file_operations sctp_remaddr_seq_fops = {
.open = sctp_remaddr_seq_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_net,
};
int __net_init sctp_remaddr_proc_init(struct net *net)
{
struct proc_dir_entry *p;
p = proc_create("remaddr", S_IRUGO, net->sctp.proc_net_sctp,
&sctp_remaddr_seq_fops);
if (!p)
return -ENOMEM;
return 0;
}