kernel/linux.git/include/net/sctp/structs.h, branch v4.14.45

sctp: fix the handling of ICMP Frag Needed for too small MTUs

2018-01-17T08:45:21+00:00

[ Upstream commit b6c5734db07079c9410147b32407f2366d584e6c ] syzbot reported a hang involving SCTP, on which it kept flooding dmesg with the message: [ 246.742374] sctp: sctp_transport_update_pmtu: Reported pmtu 508 too low, using default minimum of 512 That happened because whenever SCTP hits an ICMP Frag Needed, it tries to adjust to the new MTU and triggers an immediate retransmission. But it didn't consider the fact that MTUs smaller than the SCTP minimum MTU allowed (512) would not cause the PMTU to change, and issued the retransmission anyway (thus leading to another ICMP Frag Needed, and so on). As IPv4 (ip_rt_min_pmtu=556) and IPv6 (IPV6_MIN_MTU=1280) minimum MTU are higher than that, sctp_transport_update_pmtu() is changed to re-fetch the PMTU that got set after our request, and with that, detect if there was an actual change or not. The fix, thus, skips the immediate retransmission if the received ICMP resulted in no change, in the hope that SCTP will select another path. Note: The value being used for the minimum MTU (512, SCTP_DEFAULT_MINSEGMENT) is not right and instead it should be (576, SCTP_MIN_PMTU), but such change belongs to another patch. Changes from v1: - do not disable PMTU discovery, in the light of commit 06ad391919b2 ("[SCTP] Don't disable PMTU discovery when mtu is small") and as suggested by Xin Long. - changed the way to break the rtx loop by detecting if the icmp resulted in a change or not Changes from v2: none See-also: https://lkml.org/lkml/2017/12/22/811 Reported-by: syzbot Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sctp: remove the typedef sctp_socket_type_t

2017-08-11T17:02:44+00:00

This patch is to remove the typedef sctp_socket_type_t, and replace with enum sctp_socket_type in the places where it's using this typedef. Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: remove the typedef sctp_dbg_objcnt_entry_t

2017-08-11T17:02:43+00:00

This patch is to remove the typedef sctp_dbg_objcnt_entry_t, and replace with struct sctp_dbg_objcnt_entry in the places where it's using this typedef. Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: remove the typedef sctp_cmsgs_t

2017-08-11T17:02:43+00:00

This patch is to remove the typedef sctp_cmsgs_t, and replace with struct sctp_cmsgs in the places where it's using this typedef. Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: remove the typedef sctp_endpoint_type_t

2017-08-11T17:02:43+00:00

This patch is to remove the typedef sctp_endpoint_type_t, and replace with enum sctp_endpoint_type in the places where it's using this typedef. Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: remove the typedef sctp_sender_hb_info_t

2017-08-11T17:02:43+00:00

This patch is to remove the typedef sctp_sender_hb_info_t, and replace with struct sctp_sender_hb_info in the places where it's using this typedef. It is also to use sizeof(variable) instead of sizeof(type). Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: remove the unused typedef sctp_packet_phandler_t

2017-08-11T17:02:43+00:00

Remove this function typedef, there is even no places using it. Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: remove the typedef sctp_state_t

2017-08-07T04:33:42+00:00

This patch is to remove the typedef sctp_state_t, and replace with enum sctp_state in the places where it's using this typedef. Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: remove the typedef sctp_xmit_t

2017-08-07T04:33:42+00:00

This patch is to remove the typedef sctp_xmit_t, and replace with enum sctp_xmit in the places where it's using this typedef. Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: remove the typedef sctp_transport_cmd_t

2017-08-07T04:33:41+00:00

This patch is to remove the typedef sctp_transport_cmd_t, and replace with enum sctp_transport_cmd in the places where it's using this typedef. Signed-off-by: Xin Long Signed-off-by: David S. Miller