zero length frame filtering in NetRom
Subsystems (2)
PATCH 3/3 zero length frame filtering in NetRom
A zero length frame filter was recently introduced in ROSE protocole. Previous commit makes the same at AX25 protocole level. This patch has the same purpose for NetRom protocole.
The reason is that empty frames have no meaning in NetRom protocole.
Signed-off-by Bernard Pidoux <[email protected]>
--- net/netrom/af_netrom.c | 11 ++++++++++- 1 files changed, 10 insertions(+), 1 deletions(-)
net/netrom/af_netrom.c +10 -1
@@ -1037,6 +1037,10 @@ static int nr_sendmsg(struct kiocb *iocb, struct socket *sock,unsigned char *asmptr;int size; +/* Netrom empty data frame has no meaning : don't send */ +if (len ==0 ) +return 0 ; +if (msg->msg_flags & ~(MSG_DONTWAIT |MSG_EOR |MSG_CMSG_COMPAT ))return -EINVAL ;
@@ -1167,6 +1171,11 @@ static int nr_recvmsg(struct kiocb *iocb, struct socket *sock,skb_reset_transport_header (skb); copied = skb->len; +/* NetRom empty data frame has no meaning : ignore it */ +if (copied ==0 ) { + goto out; + } +if (copied > size) { copied = size; msg->msg_flags |=MSG_TRUNC ;
@@ -1182,7 +1191,7 @@ static int nr_recvmsg(struct kiocb *iocb, struct socket *sock, msg->msg_namelen =sizeof (*sax); -skb_free_datagram (sk, skb); +out:skb_free_datagram (sk, skb);release_sock (sk);return copied;
Signature · 1 line
1.6.0.6
From: bernard pidoux <[email protected]>
Date: Thu, 19 Mar 2009 19:18:52 +0100
Quoted 6 lines
A zero length frame filter was recently introduced in ROSE protocole. Previous commit makes the same at AX25 protocole level. This patch has the same purpose for NetRom protocole.
The reason is that empty frames have no meaning in NetRom protocole.Signed-off-by Bernard Pidoux <[email protected]>
Applied.
swapper Not tainted 2.6.29.6
Running kernel 2.6.29.6 compiled without SMP option there was a kernel panic. I don't know if it is related to /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq or to AX25 module or a configuration problem.
Here is the netconsole capture.
BUG: unable to handle kernel paging request at ffff880004c90648 IP: [<ffffffff80249451>] del_timer+0x11/0xb0 PGD 202063 PUD 206063 PMD 7e2067 PTE 4c90160 Oops: 0002 [#1] DEBUG_PAGEALLOC last sysfs file: /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq CPU 0 Modules linked in: netconsole netrom mkiss rose ax25 nfsd exportfs nfs lockd nfs_acl auth_rpcgss sunrpc af_packet ipv6 snd_via82xx snd_ac97_codec ac97_bus snd_mpu401_uart snd_rawmidi snd_seq_dummy snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_pcm i2c_viapro snd_timer snd_page_alloc snd_mixer_oss snd i2c_core soundcore sr_mod 8139cp 8139too mii shpchp pci_hotplug binfmt_misc ext3 jbd cpufreq_ondemand cpufreq_conservative cpufreq_powersave acpi_cpufreq freq_table floppy sg rtc_cmos thermal via_agp processor evdev button pata_via ata_generic ide_pci_generic pata_acpi sata_via libata sd_mod scsi_mod crc_t10dif Pid: 0, comm: swapper Not tainted 2.6.29.6-nosmp #8 MS-7258 RIP: 0010:[<ffffffff80249451>] [<ffffffff80249451>] del_timer+0x11/0xb0 RSP: 0018:ffffffff80717e00 EFLAGS: 00010246 RAX: ffffffff8067f0b8 RBX: ffff880004c90400 RCX: 0000000000000058 RDX: ffffe200009cb3d8 RSI: ffffffff8067f060 RDI: ffff880004c90618 RBP: ffffffff80717e20 R08: 0000000000000001 R09: 0000000000000490 R10: 0000000000000002 R11: ffffffff8067f008 R12: ffff880004c90618 R13: ffff880004c90400 R14: 0000000000000000 R15: ffffffff80717ed0 FS: 0000000000000000(0000) GS:ffffffff80720000(0000) knlGS:0000000000000000 CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b CR2: ffff880004c90648 CR3: 0000000074843000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process swapper (pid: 0, threadinfo ffffffff8068c000, task ffffffff80632360) Stack: ffff880004c90400 ffff880004c90400 ffff880004c90400 ffffffffa035bb30 ffffffff80717e30 ffffffffa035b850 ffffffff80717e60 ffffffffa035edb4 ffff880004c90400 ffff880004c90400 0000000000000000 ffffffffa035bb30 Call Trace: <IRQ> <0> [<ffffffffa035bb30>] ? ax25_heartbeat_expiry+0x0/0x60 [ax25] [<ffffffffa035b850>] ax25_stop_heartbeat+0x10/0x20 [ax25] [<ffffffffa035edb4>] ax25_destroy_socket+0x64/0x210 [ax25] [<ffffffffa035bb30>] ? ax25_heartbeat_expiry+0x0/0x60 [ax25] [<ffffffffa035b045>] ax25_std_heartbeat_expiry+0xf5/0x100 [ax25] [<ffffffff80217c56>] ? read_tsc+0x16/0x40 [<ffffffffa035bb55>] ax25_heartbeat_expiry+0x25/0x60 [ax25] [<ffffffff8024976c>] run_timer_softirq+0x15c/0x230 [<ffffffff8025f8ff>] ? clockevents_program_event+0x4f/0x90 [<ffffffff8024506c>] __do_softirq+0x7c/0x110 [<ffffffff8021271c>] call_softirq+0x1c/0x30 [<ffffffff8021407d>] do_softirq+0x5d/0xa0 [<ffffffff80244c95>] irq_exit+0x45/0x50 [<ffffffff80223e85>] smp_apic_timer_interrupt+0x55/0x90 [<ffffffff80212253>] apic_timer_interrupt+0x13/0x20 <EOI> <0> [<ffffffff80218afd>] ? mwait_idle+0x5d/0x70 [<ffffffff8020fdd2>] ? enter_idle+0x22/0x30 [<ffffffff8020fe2e>] ? cpu_idle+0x4e/0x80 [<ffffffff804eb5cd>] ? rest_init+0x5d/0x70 Code: 10 18 00 00 eb a6 0f 1f 40 00 48 0f b6 c2 48 c1 e0 04 48 8d 54 07 10 eb 93 90 55 48 89 e5 41 56 45 31 f6 41 55 41 54 49 89 fc 53 <48> c7 47 30 00 00 00 00 48 83 3f 00 75 16 eb 76 0f 1f 80 00 00 RIP [<ffffffff80249451>] del_timer+0x11/0xb0 RSP <ffffffff80717e00> CR2: ffff880004c90648 ---[ end trace 366e8cf762bbf316 ]--- Kernel panic - not syncing: Fatal exception in interrupt
Rebooting in 60 seconds..