kernel/linux.git/net/sctp/output.c, branch linux-7.1.y

treewide: Switch/rename to timer_delete[_sync]()

2025-04-05T08:30:12+00:00

timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree over and remove the historical wrapper inlines. Conversion was done with coccinelle plus manual fixups where necessary. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar

net: allow gso_max_size to exceed 65536

2022-05-16T09:18:55+00:00

The code for gso_max_size was added originally to allow for debugging and workaround of buggy devices that couldn't support TSO with blocks 64K in size. The original reason for limiting it to 64K was because that was the existing limits of IPv4 and non-jumbogram IPv6 length fields. With the addition of Big TCP we can remove this limit and allow the value to potentially go up to UINT_MAX and instead be limited by the tso_max_size value. So in order to support this we need to go through and clean up the remaining users of the gso_max_size value so that the values will cap at 64K for non-TCPv6 flows. In addition we can clean up the GSO_MAX_SIZE value so that 64K becomes GSO_LEGACY_MAX_SIZE and UINT_MAX will now be the upper limit for GSO_MAX_SIZE. v6: (edumazet) fixed a compile error if CONFIG_IPV6=n, in a new sk_trim_gso_size() helper. netif_set_tso_max_size() caps the requested TSO size with GSO_MAX_SIZE. Signed-off-by: Alexander Duyck Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: annotate accesses to dev->gso_max_size

2021-11-22T12:49:42+00:00

dev->gso_max_size is written under RTNL protection, or when the device is not yet visible, but is read locklessly. Add the READ_ONCE()/WRITE_ONCE() pairs, and use netif_set_gso_max_size() where we can to better document what is going on. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

sctp: allow IP fragmentation when PLPMTUD enters Error state

2021-10-29T11:21:23+00:00

Currently when PLPMTUD enters Error state, transport pathmtu will be set to MIN_PLPMTU(512) while probe is continuing with BASE_PLPMTU(1200). It will cause pathmtu to stay in a very small value, even if the real pmtu is some value like 1000. RFC8899 doesn't clearly say how to set the value in Error state. But one possibility could be keep using BASE_PLPMTU for the real pmtu, but allow to do IP fragmentation when it's in Error state. As it says in rfc8899#section-5.4: Some paths could be unable to sustain packets of the BASE_PLPMTU size. The Error State could be implemented to provide robustness to such paths. This allows fallback to a smaller than desired PLPMTU rather than suffer connectivity failure. This could utilize methods such as endpoint IP fragmentation to enable the PL sender to communicate using packets smaller than the BASE_PLPMTU. This patch is to set pmtu to BASE_PLPMTU instead of MIN_PLPMTU for Error state in sctp_transport_pl_send/toobig(), and set packet ipfragok for non-probe packets when it's in Error state. Fixes: 1dc68c194571 ("sctp: do state transition when PROBE_COUNT == MAX_PROBES on HB send path") Reported-by: Ying Xu Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: do not update transport pathmtu if SPP_PMTUD_ENABLE is not set

2021-07-21T21:17:58+00:00

Currently, in sctp_packet_config(), sctp_transport_pmtu_check() is called to update transport pathmtu with dst's mtu when dst's mtu has been changed by non sctp stack like xfrm. However, this should only happen when SPP_PMTUD_ENABLE is set, no matter where dst's mtu changed. This patch is to fix by checking SPP_PMTUD_ENABLE flag before calling sctp_transport_pmtu_check(). Thanks Jacek for reporting and looking into this issue. v1->v2: - add the missing "{" to fix the build error. Fixes: 69fec325a643 ('Revert "sctp: remove sctp_transport_pmtu_check"') Reported-by: Jacek Szafraniec Tested-by: Jacek Szafraniec Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: enable PLPMTUD when the transport is ready

2021-06-22T18:28:52+00:00

sctp_transport_pl_reset() is called whenever any of these 3 members in transport is changed: - probe_interval - param_flags & SPP_PMTUD_ENABLE - state == ACTIVE If all are true, start the PLPMTUD when it's not yet started. If any of these is false, stop the PLPMTUD when it's already running. sctp_transport_pl_update() is called when the transport dst has changed. It will restart the PLPMTUD probe. Again, the pathmtu won't change but use the dst's mtu until the Search phase is done. Note that after using PLPMTUD, the pathmtu is only initialized with the dst mtu when the transport dst changes. At other time it is updated by pl.pmtu. So sctp_transport_pmtu_check() will be called only when PLPMTUD is disabled in sctp_packet_config(). After this patch, the PLPMTUD feature from RFC8899 will be activated and can be used by users. Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: do the basic send and recv for PLPMTUD probe

2021-06-22T18:28:52+00:00

This patch does exactly what rfc8899#section-6.2.1.2 says: The SCTP sender needs to be able to determine the total size of a probe packet. The HEARTBEAT chunk could carry a Heartbeat Information parameter that includes, besides the information suggested in [RFC4960], the probe size to help an implementation associate a HEARTBEAT ACK with the size of probe that was sent. The sender could also use other methods, such as sending a nonce and verifying the information returned also contains the corresponding nonce. The length of the PAD chunk is computed by reducing the probing size by the size of the SCTP common header and the HEARTBEAT chunk. Note that HB ACK chunk will carry back whatever HB chunk carried, including the probe_size we put it in; We also check hbinfo->probe_size in the HB ACK against link->pl.probe_size to validate this HB ACK chunk. v1->v2: - Remove the unused 'sp' and add static for sctp_packet_bundle_pad(). Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: move sk_route_caps check and set into sctp_outq_flush_transports

2021-03-19T18:34:49+00:00

The sk's sk_route_caps is set in sctp_packet_config, and later it only needs to change when traversing the transport_list in a loop, as the dst might be changed in the tx path. So move sk_route_caps check and set into sctp_outq_flush_transports from sctp_packet_transmit. This also fixes a dst leak reported by Chen Yi: https://bugzilla.kernel.org/show_bug.cgi?id=212227 As calling sk_setup_caps() in sctp_packet_transmit may also set the sk_route_caps for the ctrl sock in a netns. When the netns is being deleted, the ctrl sock's releasing is later than dst dev's deleting, which will cause this dev's deleting to hang and dmesg error occurs: unregister_netdevice: waiting for xxx to become free. Usage count = 1 Reported-by: Chen Yi Fixes: bcd623d8e9fa ("sctp: call sk_setup_caps in sctp_packet_transmit instead") Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: support for sending packet over udp4 sock

2020-10-30T22:24:30+00:00

This patch does what the rfc6951#section-5.3 says for ipv4: "Within the UDP header, the source port MUST be the local UDP encapsulation port number of the SCTP stack, and the destination port MUST be the remote UDP encapsulation port number maintained for the association and the destination address to which the packet is sent (see Section 5.1). Because the SCTP packet is the UDP payload, the length of the UDP packet MUST be the length of the SCTP packet plus the size of the UDP header. The SCTP checksum MUST be computed for IPv4 and IPv6, and the UDP checksum SHOULD be computed for IPv4 and IPv6." Some places need to be adjusted in sctp_packet_transmit(): 1. For non-gso packets, when transport's encap_port is set, sctp checksum has to be done in sctp_packet_pack(), as the outer udp will use ip_summed = CHECKSUM_PARTIAL to do the offload setting for checksum. 2. Delay calling dst_clone() and skb_dst_set() for non-udp packets until sctp_v4_xmit(), as for udp packets, skb_dst_set() is not needed before calling udp_tunnel_xmit_skb(). then in sctp_v4_xmit(): 1. Go to udp_tunnel_xmit_skb() only when transport->encap_port and net->sctp.udp_port both are set, as these are one for dst port and another for src port. 2. For gso packet, SKB_GSO_UDP_TUNNEL_CSUM is set for gso_type, and with this udp checksum can be done in __skb_udp_tunnel_segment() for each segments after the sctp gso. 3. inner_mac_header and inner_transport_header are set, as these will be needed in __skb_udp_tunnel_segment() to find the right headers. 4. df and ttl are calculated, as these are the required params by udp_tunnel_xmit_skb(). 5. nocheck param has to be false, as "the UDP checksum SHOULD be computed for IPv4 and IPv6", says in rfc6951#section-5.3. v1->v2: - Use sp->udp_port instead in sctp_v4_xmit(), which is more safe. Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: Jakub Kicinski

sctp: call sk_setup_caps in sctp_packet_transmit instead

2020-10-30T22:24:25+00:00

sk_setup_caps() was originally called in Commit 90017accff61 ("sctp: Add GSO support"), as: "We have to refresh this in case we are xmiting to more than one transport at a time" This actually happens in the loop of sctp_outq_flush_transports(), and it shouldn't be tied to gso, so move it out of gso part and before sctp_packet_pack(). Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: Jakub Kicinski