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2017-12-05fix kcm_clone()Al Viro
1) it's fput() or sock_release(), not both 2) don't do fd_install() until the last failure exit. 3) not a bug per se, but... don't attach socket to struct file until it's set up. Take reserving descriptor into the caller, move fd_install() to the caller, sanitize failure exits and calling conventions. Cc: stable@vger.kernel.org # v4.6+ Acked-by: Tom Herbert <tom@herbertland.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Files removed in 'net-next' had their license header updated in 'net'. We take the remove from 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-26kcm: Remove redundant unlikely()Tobias Klauser
IS_ERR() already implies unlikely(), so it can be omitted. Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Three cases of simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-30kcm: do not attach PF_KCM sockets to avoid deadlockEric Dumazet
syzkaller had no problem to trigger a deadlock, attaching a KCM socket to another one (or itself). (original syzkaller report was a very confusing lockdep splat during a sendmsg()) It seems KCM claims to only support TCP, but no enforcement is done, so we might need to add additional checks. Fixes: ab7ac4eb9832 ("kcm: Kernel Connection Multiplexor module") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Tom Herbert <tom@quantonium.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-24strparser: initialize all callbacksEric Biggers
commit bbb03029a899 ("strparser: Generalize strparser") added more function pointers to 'struct strp_callbacks'; however, kcm_attach() was not updated to initialize them. This could cause the ->lock() and/or ->unlock() function pointers to be set to garbage values, causing a crash in strp_work(). Fix the bug by moving the callback structs into static memory, so unspecified members are zeroed. Also constify them while we're at it. This bug was found by syzkaller, which encountered the following splat: IP: 0x55 PGD 3b1ca067 P4D 3b1ca067 PUD 3b12f067 PMD 0 Oops: 0010 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 2 PID: 1194 Comm: kworker/u8:1 Not tainted 4.13.0-rc4-next-20170811 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Workqueue: kstrp strp_work task: ffff88006bb0e480 task.stack: ffff88006bb10000 RIP: 0010:0x55 RSP: 0018:ffff88006bb17540 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffff88006ce4bd60 RCX: 0000000000000000 RDX: 1ffff1000d9c97bd RSI: 0000000000000000 RDI: ffff88006ce4bc48 RBP: ffff88006bb17558 R08: ffffffff81467ab2 R09: 0000000000000000 R10: ffff88006bb17438 R11: ffff88006bb17940 R12: ffff88006ce4bc48 R13: ffff88003c683018 R14: ffff88006bb17980 R15: ffff88003c683000 FS: 0000000000000000(0000) GS:ffff88006de00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000055 CR3: 000000003c145000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: process_one_work+0xbf3/0x1bc0 kernel/workqueue.c:2098 worker_thread+0x223/0x1860 kernel/workqueue.c:2233 kthread+0x35e/0x430 kernel/kthread.c:231 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 Code: Bad RIP value. RIP: 0x55 RSP: ffff88006bb17540 CR2: 0000000000000055 ---[ end trace f0e4920047069cee ]--- Here is a C reproducer (requires CONFIG_BPF_SYSCALL=y and CONFIG_AF_KCM=y): #include <linux/bpf.h> #include <linux/kcm.h> #include <linux/types.h> #include <stdint.h> #include <sys/ioctl.h> #include <sys/socket.h> #include <sys/syscall.h> #include <unistd.h> static const struct bpf_insn bpf_insns[3] = { { .code = 0xb7 }, /* BPF_MOV64_IMM(0, 0) */ { .code = 0x95 }, /* BPF_EXIT_INSN() */ }; static const union bpf_attr bpf_attr = { .prog_type = 1, .insn_cnt = 2, .insns = (uintptr_t)&bpf_insns, .license = (uintptr_t)"", }; int main(void) { int bpf_fd = syscall(__NR_bpf, BPF_PROG_LOAD, &bpf_attr, sizeof(bpf_attr)); int inet_fd = socket(AF_INET, SOCK_STREAM, 0); int kcm_fd = socket(AF_KCM, SOCK_DGRAM, 0); ioctl(kcm_fd, SIOCKCMATTACH, &(struct kcm_attach) { .fd = inet_fd, .bpf_fd = bpf_fd }); } Fixes: bbb03029a899 ("strparser: Generalize strparser") Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Tom Herbert <tom@quantonium.net> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-01strparser: Generalize strparserTom Herbert
Generalize strparser from more than just being used in conjunction with read_sock. strparser will also be used in the send path with zero proxy. The primary change is to create strp_process function that performs the critical processing on skbs. The documentation is also updated to reflect the new uses. Signed-off-by: Tom Herbert <tom@quantonium.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01net: convert sock.sk_wmem_alloc from atomic_t to refcount_tReshetova, Elena
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-16net: socket: mark socket protocol handler structs as constlinzhang
Signed-off-by: linzhang <xiaolou4617@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-17kcm: remove a useless copy_from_user()WANG Cong
struct kcm_clone only contains fd, and kcm_clone() only writes this struct, so there is no need to copy it from user. Cc: Tom Herbert <tom@herbertland.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-24kcm: return immediately after copy_from_user() failureWANG Cong
There is no reason to continue after a copy_from_user() failure. Fixes: ab7ac4eb9832 ("kcm: Kernel Connection Multiplexor module") Cc: Tom Herbert <tom@herbertland.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-02sched/headers: Prepare to move signal wakeup & sigpending methods from ↵Ingo Molnar
<linux/sched.h> into <linux/sched/signal.h> Fix up affected files that include this signal functionality via sched.h. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-14kcm: fix a null pointer dereference in kcm_sendmsg()WANG Cong
In commit 98e3862ca2b1 ("kcm: fix 0-length case for kcm_sendmsg()") I tried to avoid skb allocation for 0-length case, but missed a check for NULL pointer in the non EOR case. Fixes: 98e3862ca2b1 ("kcm: fix 0-length case for kcm_sendmsg()") Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Tom Herbert <tom@herbertland.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-09kcm: fix 0-length case for kcm_sendmsg()WANG Cong
Dmitry reported a kernel warning: WARNING: CPU: 3 PID: 2936 at net/kcm/kcmsock.c:627 kcm_write_msgs+0x12e3/0x1b90 net/kcm/kcmsock.c:627 CPU: 3 PID: 2936 Comm: a.out Not tainted 4.10.0-rc6+ #209 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:15 [inline] dump_stack+0x2ee/0x3ef lib/dump_stack.c:51 panic+0x1fb/0x412 kernel/panic.c:179 __warn+0x1c4/0x1e0 kernel/panic.c:539 warn_slowpath_null+0x2c/0x40 kernel/panic.c:582 kcm_write_msgs+0x12e3/0x1b90 net/kcm/kcmsock.c:627 kcm_sendmsg+0x163a/0x2200 net/kcm/kcmsock.c:1029 sock_sendmsg_nosec net/socket.c:635 [inline] sock_sendmsg+0xca/0x110 net/socket.c:645 sock_write_iter+0x326/0x600 net/socket.c:848 new_sync_write fs/read_write.c:499 [inline] __vfs_write+0x483/0x740 fs/read_write.c:512 vfs_write+0x187/0x530 fs/read_write.c:560 SYSC_write fs/read_write.c:607 [inline] SyS_write+0xfb/0x230 fs/read_write.c:599 entry_SYSCALL_64_fastpath+0x1f/0xc2 when calling syscall(__NR_write, sock2, 0x208aaf27ul, 0x0ul) on a KCM seqpacket socket. It appears that kcm_sendmsg() does not handle len==0 case correctly, which causes an empty skb is allocated and queued. Fix this by skipping the skb allocation for len==0 case. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Tom Herbert <tom@herbertland.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-07Merge branch 'work.splice_read' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull VFS splice updates from Al Viro: "There's a bunch of branches this cycle, both mine and from other folks and I'd rather send pull requests separately. This one is the conversion of ->splice_read() to ITER_PIPE iov_iter (and introduction of such). Gets rid of a lot of code in fs/splice.c and elsewhere; there will be followups, but these are for the next cycle... Some pipe/splice-related cleanups from Miklos in the same branch as well" * 'work.splice_read' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: pipe: fix comment in pipe_buf_operations pipe: add pipe_buf_steal() helper pipe: add pipe_buf_confirm() helper pipe: add pipe_buf_release() helper pipe: add pipe_buf_get() helper relay: simplify relay_file_read() switch default_file_splice_read() to use of pipe-backed iov_iter switch generic_file_splice_read() to use of ->read_iter() new iov_iter flavour: pipe-backed fuse_dev_splice_read(): switch to add_to_pipe() skb_splice_bits(): get rid of callback new helper: add_to_pipe() splice: lift pipe_lock out of splice_to_pipe() splice: switch get_iovec_page_array() to iov_iter splice_to_pipe(): don't open-code wakeup_pipe_readers() consistent treatment of EFAULT on O_DIRECT read/write
2016-10-03skb_splice_bits(): get rid of callbackAl Viro
since pipe_lock is the outermost now, we don't need to drop/regain socket locks around the call of splice_to_pipe() from skb_splice_bits(), which kills the need to have a socket-specific callback; we can just call splice_to_pipe() and be done with that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-12Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: drivers/net/ethernet/mediatek/mtk_eth_soc.c drivers/net/ethernet/qlogic/qed/qed_dcbx.c drivers/net/phy/Kconfig All conflicts were cases of overlapping commits. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-31kcm: fix a socket double freeWANG Cong
Dmitry reported a double free on kcm socket, which could be easily reproduced by: #include <unistd.h> #include <sys/syscall.h> int main() { int fd = syscall(SYS_socket, 0x29ul, 0x5ul, 0x0ul, 0, 0, 0); syscall(SYS_ioctl, fd, 0x89e2ul, 0x20a98000ul, 0, 0, 0); return 0; } This is because on the error path, after we install the new socket file, we call sock_release() to clean up the socket, which leaves the fd pointing to a freed socket. Fix this by calling sys_close() on that fd directly. Fixes: ab7ac4eb9832 ("kcm: Kernel Connection Multiplexor module") Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Tom Herbert <tom@herbertland.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-28kcm: Remove TCP specific references from kcm and strparserTom Herbert
kcm and strparser need to work with any type of stream socket not just TCP. Eliminate references to TCP and call generic proto_ops functions of read_sock and peek_len. Also in strp_init check if the socket support the proto_ops read_sock and peek_len. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-23kcm: Fix locking issueTom Herbert
Lock the lower socket in kcm_unattach. Release during call to strp_done since that function cancels the RX timers and work queue with sync. Also added some status information in psock reporting. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-17kcm: Use stream parserTom Herbert
Adapt KCM to use the stream parser. This mostly involves removing the RX handling and setting up the strparser using the interface. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-25kcm: remove redundant -ve error check and return pathColin Ian King
The check for a -ve error is redundant, remove it and just immediately return the return value from the call to seq_open_net. Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-01bpf: refactor bpf_prog_get and type check into helperDaniel Borkmann
Since bpf_prog_get() and program type check is used in a couple of places, refactor this into a small helper function that we can make use of. Since the non RO prog->aux part is not used in performance critical paths and a program destruction via RCU is rather very unlikley when doing the put, we shouldn't have an issue just doing the bpf_prog_get() + prog->type != type check, but actually not taking the ref at all (due to being in fdget() / fdput() section of the bpf fd) is even cleaner and makes the diff smaller as well, so just go for that. Callsites are changed to make use of the new helper where possible. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-22kcm: fix /proc memory leakJiri Slaby
Every open of /proc/net/kcm leaks 16 bytes of memory as is reported by kmemleak: unreferenced object 0xffff88059c0e3458 (size 192): comm "cat", pid 1401, jiffies 4294935742 (age 310.720s) hex dump (first 32 bytes): 28 45 71 96 05 88 ff ff 00 10 00 00 00 00 00 00 (Eq............. 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff8156a2de>] kmem_cache_alloc_trace+0x16e/0x230 [<ffffffff8162a479>] seq_open+0x79/0x1d0 [<ffffffffa0578510>] kcm_seq_open+0x0/0x30 [kcm] [<ffffffff8162a479>] seq_open+0x79/0x1d0 [<ffffffff8162a8cf>] __seq_open_private+0x2f/0xa0 [<ffffffff81712548>] seq_open_net+0x38/0xa0 ... It is caused by a missing free in the ->release path. So fix it by providing seq_release_net as the ->release method. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Fixes: cd6e111bf5 (kcm: Add statistics and proc interfaces) Cc: "David S. Miller" <davem@davemloft.net> Cc: Tom Herbert <tom@herbertland.com> Cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-19kcm: fix a signedness in kcm_splice_read()WANG Cong
skb_splice_bits() returns int, kcm_splice_read() returns ssize_t, both are signed. We may need another patch to make them all ssize_t, but that deserves a separated patch. Fixes: 91687355b927 ("kcm: Splice support") Reported-by: David Binderman <linuxdev.baldrick@gmail.com> Cc: Tom Herbert <tom@herbertland.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-09kcm: Add receive message timeoutTom Herbert
This patch adds receive timeout for message assembly on the attached TCP sockets. The timeout is set when a new messages is started and the whole message has not been received by TCP (not in the receive queue). If the completely message is subsequently received the timer is cancelled, if the timer expires the RX side is aborted. The timeout value is taken from the socket timeout (SO_RCVTIMEO) that is set on a TCP socket (i.e. set by get sockopt before attaching a TCP socket to KCM. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-09kcm: Add memory limit for receive message constructionTom Herbert
Message assembly is performed on the TCP socket. This is logically equivalent of an application that performs a peek on the socket to find out how much memory is needed for a receive buffer. The receive socket buffer also provides the maximum message size which is checked. The receive algorithm is something like: 1) Receive the first skbuf for a message (or skbufs if multiple are needed to determine message length). 2) Check the message length against the number of bytes in the TCP receive queue (tcp_inq()). - If all the bytes of the message are in the queue (incluing the skbuf received), then proceed with message assembly (it should complete with the tcp_read_sock) - Else, mark the psock with the number of bytes needed to complete the message. 3) In TCP data ready function, if the psock indicates that we are waiting for the rest of the bytes of a messages, check the number of queued bytes against that. - If there are still not enough bytes for the message, just return - Else, clear the waiting bytes and proceed to receive the skbufs. The message should now be received in one tcp_read_sock Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-09kcm: Sendpage supportTom Herbert
Implement kcm_sendpage. Set in sendpage to kcm_sendpage in both dgram and seqpacket ops. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-09kcm: Splice supportTom Herbert
Implement kcm_splice_read. This is supported only for seqpacket. Add kcm_seqpacket_ops and set splice read to kcm_splice_read. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-09kcm: Add statistics and proc interfacesTom Herbert
This patch adds various counters for KCM. These include counters for messages and bytes received or sent, as well as counters for number of attached/unattached TCP sockets and other error or edge events. The statistics are exposed via a proc interface. /proc/net/kcm provides statistics per KCM socket and per psock (attached TCP sockets). /proc/net/kcm_stats provides aggregate statistics. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-09kcm: Kernel Connection Multiplexor moduleTom Herbert
This module implements the Kernel Connection Multiplexor. Kernel Connection Multiplexor (KCM) is a facility that provides a message based interface over TCP for generic application protocols. With KCM an application can efficiently send and receive application protocol messages over TCP using datagram sockets. For more information see the included Documentation/networking/kcm.txt Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>