user/sven/linux.git/include/net/sctp, branch v3.17

net: sctp: fix ABI mismatch through sctp_assoc_to_state helper

2014-08-30T03:31:08Z

Since SCTP day 1, that is, 19b55a2af145 ("Initial commit") from lksctp tree, the official header carries a copy of enum sctp_sstat_state that looks like (compared to the current in-kernel enumeration): User definition: Kernel definition: enum sctp_sstat_state { typedef enum { SCTP_EMPTY = 0, SCTP_CLOSED = 1, SCTP_STATE_CLOSED = 0, SCTP_COOKIE_WAIT = 2, SCTP_STATE_COOKIE_WAIT = 1, SCTP_COOKIE_ECHOED = 3, SCTP_STATE_COOKIE_ECHOED = 2, SCTP_ESTABLISHED = 4, SCTP_STATE_ESTABLISHED = 3, SCTP_SHUTDOWN_PENDING = 5, SCTP_STATE_SHUTDOWN_PENDING = 4, SCTP_SHUTDOWN_SENT = 6, SCTP_STATE_SHUTDOWN_SENT = 5, SCTP_SHUTDOWN_RECEIVED = 7, SCTP_STATE_SHUTDOWN_RECEIVED = 6, SCTP_SHUTDOWN_ACK_SENT = 8, SCTP_STATE_SHUTDOWN_ACK_SENT = 7, }; } sctp_state_t; This header was later on also placed into the uapi, so that user space programs can compile without having , but the shipped with instead. While RFC6458 under 8.2.1.Association Status (SCTP_STATUS) says that sstat_state can range from SCTP_CLOSED to SCTP_SHUTDOWN_ACK_SENT, we nevertheless have a what it appears to be dummy SCTP_EMPTY state from the very early days. While it seems to do just nothing, commit 0b8f9e25b0aa ("sctp: remove completely unsed EMPTY state") did the right thing and removed this dead code. That however, causes an off-by-one when the user asks the SCTP stack via SCTP_STATUS API and checks for the current socket state thus yielding possibly undefined behaviour in applications as they expect the kernel to tell the right thing. The enumeration had to be changed however as based on the current socket state, we access a function pointer lookup-table through this. Therefore, I think the best way to deal with this is just to add a helper function sctp_assoc_to_state() to encapsulate the off-by-one quirk. Reported-by: Tristan Su Fixes: 0b8f9e25b0aa ("sctp: remove completely unsed EMPTY state") Signed-off-by: Daniel Borkmann Acked-by: Vlad Yasevich Signed-off-by: David S. Miller

sctp: Fixup v4mapped behaviour to comply with Sock API

2014-08-01T04:49:06Z

The SCTP socket extensions API document describes the v4mapping option as follows: 8.1.15. Set/Clear IPv4 Mapped Addresses (SCTP_I_WANT_MAPPED_V4_ADDR) This socket option is a Boolean flag which turns on or off the mapping of IPv4 addresses. If this option is turned on, then IPv4 addresses will be mapped to V6 representation. If this option is turned off, then no mapping will be done of V4 addresses and a user will receive both PF_INET6 and PF_INET type addresses on the socket. See [RFC3542] for more details on mapped V6 addresses. This description isn't really in line with what the code does though. Introduce addr_to_user (renamed addr_v4map), which should be called before any sockaddr is passed back to user space. The new function places the sockaddr into the correct format depending on the SCTP_I_WANT_MAPPED_V4_ADDR option. Audit all places that touched v4mapped and either sanely construct a v4 or v6 address then call addr_to_user, or drop the unnecessary v4mapped check entirely. Audit all places that call addr_to_user and verify they are on a sycall return path. Add a custom getname that formats the address properly. Several bugs are addressed: - SCTP_I_WANT_MAPPED_V4_ADDR=0 often returned garbage for addresses to user space - The addr_len returned from recvmsg was not correct when returning AF_INET on a v6 socket - flowlabel and scope_id were not zerod when promoting a v4 to v6 - Some syscalls like bind and connect behaved differently depending on v4mapped Tested bind, getpeername, getsockname, connect, and recvmsg for proper behaviour in v4mapped = 1 and 0 cases. Signed-off-by: Neil Horman Tested-by: Jason Gunthorpe Signed-off-by: Jason Gunthorpe Signed-off-by: David S. Miller

net: sctp: Rename SCTP_XMIT_NAGLE_DELAY to SCTP_XMIT_DELAY

2014-07-22T20:32:11Z

MSG_MORE and 'corking' a socket would require that the transmit of a data chunk be delayed. Rename the return value to be less specific. Signed-off-by: David Laight Acked-by: Vlad Yasevich Signed-off-by: David S. Miller

net: sctp: implement rfc6458, 5.3.6. SCTP_NXTINFO cmsg support

2014-07-16T21:40:03Z

This patch implements section 5.3.6. of RFC6458, that is, support for 'SCTP Next Receive Information Structure' (SCTP_NXTINFO) which is placed into ancillary data cmsghdr structure for each recvmsg() call, if this information is already available when delivering the current message. This option can be enabled/disabled via setsockopt(2) on SOL_SCTP level by setting an int value with 1/0 for SCTP_RECVNXTINFO in user space applications as per RFC6458, section 8.1.30. The sctp_nxtinfo structure is defined as per RFC as below ... struct sctp_nxtinfo { uint16_t nxt_sid; uint16_t nxt_flags; uint32_t nxt_ppid; uint32_t nxt_length; sctp_assoc_t nxt_assoc_id; }; ... and provided under cmsg_level IPPROTO_SCTP, cmsg_type SCTP_NXTINFO, while cmsg_data[] contains struct sctp_nxtinfo. Joint work with Daniel Borkmann. Signed-off-by: Geir Ola Vaagland Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller

net: sctp: implement rfc6458, 5.3.5. SCTP_RCVINFO cmsg support

2014-07-16T21:40:03Z

This patch implements section 5.3.5. of RFC6458, that is, support for 'SCTP Receive Information Structure' (SCTP_RCVINFO) which is placed into ancillary data cmsghdr structure for each recvmsg() call. This option can be enabled/disabled via setsockopt(2) on SOL_SCTP level by setting an int value with 1/0 for SCTP_RECVRCVINFO in user space applications as per RFC6458, section 8.1.29. The sctp_rcvinfo structure is defined as per RFC as below ... struct sctp_rcvinfo { uint16_t rcv_sid; uint16_t rcv_ssn; uint16_t rcv_flags; <-- 2 bytes hole --> uint32_t rcv_ppid; uint32_t rcv_tsn; uint32_t rcv_cumtsn; uint32_t rcv_context; sctp_assoc_t rcv_assoc_id; }; ... and provided under cmsg_level IPPROTO_SCTP, cmsg_type SCTP_RCVINFO, while cmsg_data[] contains struct sctp_rcvinfo. An sctp_rcvinfo item always corresponds to the data in msg_iov. Joint work with Daniel Borkmann. Signed-off-by: Geir Ola Vaagland Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller

net: sctp: implement rfc6458, 5.3.4. SCTP_SNDINFO cmsg support

2014-07-16T21:40:03Z

This patch implements section 5.3.4. of RFC6458, that is, support for 'SCTP Send Information Structure' (SCTP_SNDINFO) which can be placed into ancillary data cmsghdr structure for sendmsg() calls. The sctp_sndinfo structure is defined as per RFC as below ... struct sctp_sndinfo { uint16_t snd_sid; uint16_t snd_flags; uint32_t snd_ppid; uint32_t snd_context; sctp_assoc_t snd_assoc_id; }; ... and supplied under cmsg_level IPPROTO_SCTP, cmsg_type SCTP_SNDINFO, while cmsg_data[] contains struct sctp_sndinfo. An sctp_sndinfo item always corresponds to the data in msg_iov. Joint work with Daniel Borkmann. Signed-off-by: Geir Ola Vaagland Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller

net: sctp: Use pointers (not array indexes) to access sctp_cmd_seq_t.cmds[].

2014-07-08T21:39:00Z

Using pointers into sctp_cmd_seq_t.cmds[] lets the compiler generate much better code. Use the last entry first to optimise the overflow check. Signed-off-by: David Laight Signed-off-by: David S. Miller

net: sctp: Optimise the way 'sctp_arg_t' values are initialised.

2014-07-08T21:39:00Z

Even if memset() is inlined (as on x86) using it to zero the union generates a memory word write of zero, followed by a write of the smaller field, and then a read of the word. As well as being a lot of instructions the sequence is unlikely to be optimised by the store-load forward hardware so will be slow. Instead allocate a field of the union that is the same size as the entire union and write a zero value to it. The compiler will then generate the required value in a register. Zeroing the union shouldn't be necessary, but this patch series isn't intended to have a behavioural change. Signed-off-by: David Laight Signed-off-by: David S. Miller

net: sctp: Inline the functions from command.c

2014-07-08T21:38:48Z

sctp_init_cmd_seq() and sctp_next_cmd() are only called from one place. The call sequence for sctp_add_cmd_sf() is likely to be longer than the inlined code. With sctp_add_cmd_sf() inlined the compiler can optimise repeated calls. Signed-off-by: David Laight Signed-off-by: David S. Miller

net: sctp: improve timer slack calculation for transport HBs

2014-07-03T01:44:07Z

RFC4960, section 8.3 says: On an idle destination address that is allowed to heartbeat, it is recommended that a HEARTBEAT chunk is sent once per RTO of that destination address plus the protocol parameter 'HB.interval', with jittering of +/- 50% of the RTO value, and exponential backoff of the RTO if the previous HEARTBEAT is unanswered. Currently, we calculate jitter via sctp_jitter() function first, and then add its result to the current RTO for the new timeout: TMO = RTO + (RAND() % RTO) - (RTO / 2) `------------------------^-=> sctp_jitter() Instead, we can just simplify all this by directly calculating: TMO = (RTO / 2) + (RAND() % RTO) With the help of prandom_u32_max(), we don't need to open code our own global PRNG, but can instead just make use of the per CPU implementation of prandom with better quality numbers. Also, we can now spare us the conditional for divide by zero check since no div or mod operation needs to be used. Note that prandom_u32_max() won't emit the same result as a mod operation, but we really don't care here as we only want to have a random number scaled into RTO interval. Note, exponential RTO backoff is handeled elsewhere, namely in sctp_do_8_2_transport_strike(). Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller