osmocom-net-gprs May 2017

osmocom-net-gprs@lists.osmocom.org

8 participants
3 discussions

[PATCH] net: fix potential null pointer dereference
by Gustavo A. R. Silva 25 May '17

25 May '17

Add null check to avoid a potential null pointer dereference. Addresses-Coverity-ID: 1408831 Signed-off-by: Gustavo A. R. Silva <garsilva(a)embeddedor.com> --- drivers/net/gtp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c index 4fea1b3..7b652bb 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -873,7 +873,7 @@ static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[]) /* Check if there's an existing gtpX device to configure */ dev = dev_get_by_index_rcu(net, nla_get_u32(nla[GTPA_LINK])); - if (dev->netdev_ops == &gtp_netdev_ops) + if (dev && dev->netdev_ops == &gtp_netdev_ops) gtp = netdev_priv(dev); put_net(net); -- 2.5.0

3 2

Removing FCS from SNDCP packages
by Holger Freyther 16 May '17

16 May '17

Hi, I see that while adding decompression support dexter has fixed a bug in the sndcp code. Before the GTP-U frame would include the LLC FCS and now we do this: npdu_len = (msg->data + msg->len) - npdu - 3; What I wonder (and the commit message didn't say is) was the fragment part handled as well. The calculation is: /* make sure to subtract length of SNDCP header from 'len' */ rc = defrag_enqueue(sne, suh->seg_nr, data, len - (data - hdr)); and len is passed in from the TLV struct in gprs_llc_rcvmsg. I think the fragmented case is working okay. Shall we try to unify the length calculation to rely on the local "len" variable instead of checking msg->data+msg->len? cheers holger

3 3

kernel-to-kernel gtp implementation
by fırat sönmez 05 May '17

05 May '17

Hi, I am currently working in a project where I was asked to implement a GTP tunnel from client to company servers. I have read through osmocom pages and tried to implement the simple network structure. I have seen from Basic testing of openGGSN page: " test GTP-U interoperability of the kernel with at least one other implementation, not just kernel-to-kernel (which currently is not supported in the kernel, as it only implements the GGSN/P-GW role) " I would not like to implement openGGSN but just linux-kernel-gtp-u implementation between two kernels. To achieve kernel-to-kernel implementation, I found sgsn patch on the internet: https://patchwork.ozlabs.org/patch/739408/ and there is already a kernel-gtp-U in osmocom. So, my basic network structure is below. [image: Satır içi resim 2] I would like make a tunnel between sgsn and ggsn. I have used libgtpnl tools to create link and then tunnel. I have added a default gateway GTP interface to route table on sgsn side, but the packets cannot reach ggsn side. Is there any detailed explanation for a simple bidirectional tunnel setup. If so, it would be so nice to know about. Thank you for all your efforts, Fırat

2 1

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

osmocom-net-gprs May 2017