linux/net/x25/x25_dev.c

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* X.25 Packet Layer release 002
*
* This is ALPHA test software. This code may break your machine, randomly fail to work with new
* releases, misbehave and/or generally screw up. It might even work.
*
* This code REQUIRES 2.1.15 or higher
*
* History
* X.25 001 Jonathan Naylor Started coding.
* 2000-09-04 Henner Eisen Prevent freeing a dangling skb.
*/
#define pr_fmt(fmt) "X25: " fmt
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include <net/sock.h>
#include <linux/if_arp.h>
#include <net/x25.h>
#include <net/x25device.h>
static int x25_receive_data(struct sk_buff *skb, struct x25_neigh *nb)
{
struct sock *sk;
unsigned short frametype;
unsigned int lci;
if (!pskb_may_pull(skb, X25_STD_MIN_LEN))
return 0;
frametype = skb->data[2];
lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF);
/*
* LCI of zero is always for us, and its always a link control
* frame.
*/
if (lci == 0) {
x25_link_control(skb, nb, frametype);
return 0;
}
/*
* Find an existing socket.
*/
if ((sk = x25_find_socket(lci, nb)) != NULL) {
int queued = 1;
skb_reset_transport_header(skb);
bh_lock_sock(sk);
if (!sock_owned_by_user(sk)) {
queued = x25_process_rx_frame(sk, skb);
} else {
net: silence KCSAN warnings around sk_add_backlog() calls sk_add_backlog() callers usually read sk->sk_rcvbuf without owning the socket lock. This means sk_rcvbuf value can be changed by other cpus, and KCSAN complains. Add READ_ONCE() annotations to document the lockless nature of these reads. Note that writes over sk_rcvbuf should also use WRITE_ONCE(), but this will be done in separate patches to ease stable backports (if we decide this is relevant for stable trees). BUG: KCSAN: data-race in tcp_add_backlog / tcp_recvmsg write to 0xffff88812ab369f8 of 8 bytes by interrupt on cpu 1: __sk_add_backlog include/net/sock.h:902 [inline] sk_add_backlog include/net/sock.h:933 [inline] tcp_add_backlog+0x45a/0xcc0 net/ipv4/tcp_ipv4.c:1737 tcp_v4_rcv+0x1aba/0x1bf0 net/ipv4/tcp_ipv4.c:1925 ip_protocol_deliver_rcu+0x51/0x470 net/ipv4/ip_input.c:204 ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:442 [inline] ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5004 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5118 netif_receive_skb_internal+0x59/0x190 net/core/dev.c:5208 napi_skb_finish net/core/dev.c:5671 [inline] napi_gro_receive+0x28f/0x330 net/core/dev.c:5704 receive_buf+0x284/0x30b0 drivers/net/virtio_net.c:1061 virtnet_receive drivers/net/virtio_net.c:1323 [inline] virtnet_poll+0x436/0x7d0 drivers/net/virtio_net.c:1428 napi_poll net/core/dev.c:6352 [inline] net_rx_action+0x3ae/0xa50 net/core/dev.c:6418 read to 0xffff88812ab369f8 of 8 bytes by task 7271 on cpu 0: tcp_recvmsg+0x470/0x1a30 net/ipv4/tcp.c:2047 inet_recvmsg+0xbb/0x250 net/ipv4/af_inet.c:838 sock_recvmsg_nosec net/socket.c:871 [inline] sock_recvmsg net/socket.c:889 [inline] sock_recvmsg+0x92/0xb0 net/socket.c:885 sock_read_iter+0x15f/0x1e0 net/socket.c:967 call_read_iter include/linux/fs.h:1864 [inline] new_sync_read+0x389/0x4f0 fs/read_write.c:414 __vfs_read+0xb1/0xc0 fs/read_write.c:427 vfs_read fs/read_write.c:461 [inline] vfs_read+0x143/0x2c0 fs/read_write.c:446 ksys_read+0xd5/0x1b0 fs/read_write.c:587 __do_sys_read fs/read_write.c:597 [inline] __se_sys_read fs/read_write.c:595 [inline] __x64_sys_read+0x4c/0x60 fs/read_write.c:595 do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 7271 Comm: syz-fuzzer Not tainted 5.3.0+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-10-09 22:21:13 +00:00
queued = !sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf));
}
bh_unlock_sock(sk);
sock_put(sk);
return queued;
}
/*
* Is is a Call Request ? if so process it.
*/
if (frametype == X25_CALL_REQUEST)
return x25_rx_call_request(skb, nb, lci);
/*
* Its not a Call Request, nor is it a control frame.
* Can we forward it?
*/
if (x25_forward_data(lci, nb, skb)) {
if (frametype == X25_CLEAR_CONFIRMATION) {
x25_clear_forward_by_lci(lci);
}
kfree_skb(skb);
return 1;
}
/*
x25_transmit_clear_request(nb, lci, 0x0D);
*/
if (frametype != X25_CLEAR_CONFIRMATION)
pr_debug("x25_receive_data(): unknown frame type %2x\n",frametype);
return 0;
}
int x25_lapb_receive_frame(struct sk_buff *skb, struct net_device *dev,
struct packet_type *ptype, struct net_device *orig_dev)
{
struct sk_buff *nskb;
struct x25_neigh *nb;
if (!net_eq(dev_net(dev), &init_net))
goto drop;
nskb = skb_copy(skb, GFP_ATOMIC);
if (!nskb)
goto drop;
kfree_skb(skb);
skb = nskb;
/*
* Packet received from unrecognised device, throw it away.
*/
nb = x25_get_neigh(dev);
if (!nb) {
pr_debug("unknown neighbour - %s\n", dev->name);
goto drop;
}
if (!pskb_may_pull(skb, 1))
return 0;
switch (skb->data[0]) {
case X25_IFACE_DATA:
skb_pull(skb, 1);
if (x25_receive_data(skb, nb)) {
x25_neigh_put(nb);
goto out;
}
break;
case X25_IFACE_CONNECT:
x25_link_established(nb);
break;
case X25_IFACE_DISCONNECT:
x25_link_terminated(nb);
break;
}
x25_neigh_put(nb);
drop:
kfree_skb(skb);
out:
return 0;
}
void x25_establish_link(struct x25_neigh *nb)
{
struct sk_buff *skb;
unsigned char *ptr;
switch (nb->dev->type) {
case ARPHRD_X25:
if ((skb = alloc_skb(1, GFP_ATOMIC)) == NULL) {
pr_err("x25_dev: out of memory\n");
return;
}
ptr = skb_put(skb, 1);
*ptr = X25_IFACE_CONNECT;
break;
#if IS_ENABLED(CONFIG_LLC)
case ARPHRD_ETHER:
return;
#endif
default:
return;
}
skb->protocol = htons(ETH_P_X25);
skb->dev = nb->dev;
dev_queue_xmit(skb);
}
void x25_terminate_link(struct x25_neigh *nb)
{
struct sk_buff *skb;
unsigned char *ptr;
#if IS_ENABLED(CONFIG_LLC)
if (nb->dev->type == ARPHRD_ETHER)
return;
#endif
if (nb->dev->type != ARPHRD_X25)
return;
skb = alloc_skb(1, GFP_ATOMIC);
if (!skb) {
pr_err("x25_dev: out of memory\n");
return;
}
ptr = skb_put(skb, 1);
*ptr = X25_IFACE_DISCONNECT;
skb->protocol = htons(ETH_P_X25);
skb->dev = nb->dev;
dev_queue_xmit(skb);
}
void x25_send_frame(struct sk_buff *skb, struct x25_neigh *nb)
{
unsigned char *dptr;
skb_reset_network_header(skb);
switch (nb->dev->type) {
case ARPHRD_X25:
dptr = skb_push(skb, 1);
*dptr = X25_IFACE_DATA;
break;
#if IS_ENABLED(CONFIG_LLC)
case ARPHRD_ETHER:
kfree_skb(skb);
return;
#endif
default:
kfree_skb(skb);
return;
}
skb->protocol = htons(ETH_P_X25);
skb->dev = nb->dev;
dev_queue_xmit(skb);
}