05 Aug, 2020
1 commit
-
commit bbc8a99e952226c585ac17477a85ef1194501762 upstream.
rds_notify_queue_get() is potentially copying uninitialized kernel stack
memory to userspace since the compiler may leave a 4-byte hole at the end
of `cmsg`.In 2016 we tried to fix this issue by doing `= { 0 };` on `cmsg`, which
unfortunately does not always initialize that 4-byte hole. Fix it by using
memset() instead.Cc: stable@vger.kernel.org
Fixes: f037590fff30 ("rds: fix a leak of kernel memory")
Fixes: bdbe6fbc6a2f ("RDS: recv.c")
Suggested-by: Dan Carpenter
Signed-off-by: Peilin Ye
Acked-by: Santosh Shilimkar
Signed-off-by: David S. Miller
Signed-off-by: Greg Kroah-Hartman
03 Sep, 2019
1 commit
-
r8152 conflicts are the NAPI fixes in 'net' overlapping with
some tasklet stuff in net-nextSigned-off-by: David S. Miller
28 Aug, 2019
1 commit
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The rds6_inc_info_copy() function has a couple struct members which
are leaking stack information. The ->tos field should hold actual
information and the ->flags field needs to be zeroed out.Fixes: 3eb450367d08 ("rds: add type of service(tos) infrastructure")
Fixes: b7ff8b1036f0 ("rds: Extend RDS API for IPv6 support")
Reported-by: 黄ID蝴蝶
Signed-off-by: Dan Carpenter
Signed-off-by: Ka-Cheong Poon
Acked-by: Santosh Shilimkar
Signed-off-by: David S. Miller
24 Aug, 2019
1 commit
-
Add the RDMA cookie and RX timestamp to the usercopy whitelist.
After the introduction of hardened usercopy whitelisting
(https://lwn.net/Articles/727322/), a warning is displayed when the
RDMA cookie or RX timestamp is copied to userspace:kernel: WARNING: CPU: 3 PID: 5750 at
mm/usercopy.c:81 usercopy_warn+0x8e/0xa6
[...]
kernel: Call Trace:
kernel: __check_heap_object+0xb8/0x11b
kernel: __check_object_size+0xe3/0x1bc
kernel: put_cmsg+0x95/0x115
kernel: rds_recvmsg+0x43d/0x620 [rds]
kernel: sock_recvmsg+0x43/0x4a
kernel: ___sys_recvmsg+0xda/0x1e6
kernel: ? __handle_mm_fault+0xcae/0xf79
kernel: __sys_recvmsg+0x51/0x8a
kernel: SyS_recvmsg+0x12/0x1c
kernel: do_syscall_64+0x79/0x1aeWhen the whitelisting feature was introduced, the memory for the RDMA
cookie and RX timestamp in RDS was not added to the whitelist, causing
the warning above.Signed-off-by: Dag Moxnes
Tested-by: Jenny
Acked-by: Santosh Shilimkar
Signed-off-by: David S. Miller
05 Feb, 2019
1 commit
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RDS Service type (TOS) is user-defined and needs to be configured
via RDS IOCTL interface. It must be set before initiating any
traffic and once set the TOS can not be changed. All out-going
traffic from the socket will be associated with its TOS.Reviewed-by: Sowmini Varadhan
Signed-off-by: Santosh Shilimkar
[yanjun.zhu@oracle.com: Adapted original patch with ipv6 changes]
Signed-off-by: Zhu Yanjun
04 Feb, 2019
3 commits
-
Add SO_TIMESTAMP_NEW and SO_TIMESTAMPNS_NEW variants of
socket timestamp options.
These are the y2038 safe versions of the SO_TIMESTAMP_OLD
and SO_TIMESTAMPNS_OLD for all architectures.Note that the format of scm_timestamping.ts[0] is not changed
in this patch.Signed-off-by: Deepa Dinamani
Acked-by: Willem de Bruijn
Cc: jejb@parisc-linux.org
Cc: ralf@linux-mips.org
Cc: rth@twiddle.net
Cc: linux-alpha@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-parisc@vger.kernel.org
Cc: linux-rdma@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Signed-off-by: David S. Miller -
As part of y2038 solution, all internal uses of
struct timeval are replaced by struct __kernel_old_timeval
and struct compat_timeval by struct old_timeval32.
Make socket timestamps use these new types.This is mainly to be able to verify that the kernel build
is y2038 safe when such non y2038 safe types are not
supported anymore.Signed-off-by: Deepa Dinamani
Acked-by: Willem de Bruijn
Cc: isdn@linux-pingi.de
Signed-off-by: David S. Miller -
SO_TIMESTAMP, SO_TIMESTAMPNS and SO_TIMESTAMPING options, the
way they are currently defined, are not y2038 safe.
Subsequent patches in the series add new y2038 safe versions
of these options which provide 64 bit timestamps on all
architectures uniformly.
Hence, rename existing options with OLD tag suffixes.Also note that kernel will not use the untagged SO_TIMESTAMP*
and SCM_TIMESTAMP* options internally anymore.Signed-off-by: Deepa Dinamani
Acked-by: Willem de Bruijn
Cc: deller@gmx.de
Cc: dhowells@redhat.com
Cc: jejb@parisc-linux.org
Cc: ralf@linux-mips.org
Cc: rth@twiddle.net
Cc: linux-afs@lists.infradead.org
Cc: linux-alpha@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-parisc@vger.kernel.org
Cc: linux-rdma@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Signed-off-by: David S. Miller
17 Sep, 2018
1 commit
-
The function rds_inc_init is in recv process. To use memset can optimize
the function rds_inc_init.
The test result:Before:
1) + 24.950 us | rds_inc_init [rds]();
After:
1) + 10.990 us | rds_inc_init [rds]();Acked-by: Santosh Shilimkar
Signed-off-by: Zhu Yanjun
Signed-off-by: David S. Miller
02 Sep, 2018
1 commit
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rds is the last in-kernel user of the old do_gettimeofday()
function. Convert it over to ktime_get_real() to make it
work more like the generic socket timestamps, and to let
us kill off do_gettimeofday().A follow-up patch will have to change the user space interface
to deal better with 32-bit tasks, which may use an incompatible
layout for 'struct timespec'.Signed-off-by: Arnd Bergmann
Acked-by: Santosh Shilimkar
Signed-off-by: David S. Miller
02 Aug, 2018
1 commit
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This patch removes the IPv6 dependency from RDS.
Signed-off-by: Ka-Cheong Poon
Acked-by: Santosh Shilimkar
Signed-off-by: David S. Miller
24 Jul, 2018
3 commits
-
There are many data structures (RDS socket options) used by RDS apps
which use a 32 bit integer to store IP address. To support IPv6,
struct in6_addr needs to be used. To ensure backward compatibility, a
new data structure is introduced for each of those data structures
which use a 32 bit integer to represent an IP address. And new socket
options are introduced to use those new structures. This means that
existing apps should work without a problem with the new RDS module.
For apps which want to use IPv6, those new data structures and socket
options can be used. IPv4 mapped address is used to represent IPv4
address in the new data structures.v4: Revert changes to SO_RDS_TRANSPORT
Signed-off-by: Ka-Cheong Poon
Acked-by: Santosh Shilimkar
Signed-off-by: David S. Miller -
This patch enables RDS to use IPv6 addresses. For RDS/TCP, the
listener is now an IPv6 endpoint which accepts both IPv4 and IPv6
connection requests. RDS/RDMA/IB uses a private data (struct
rds_ib_connect_private) exchange between endpoints at RDS connection
establishment time to support RDMA. This private data exchange uses a
32 bit integer to represent an IP address. This needs to be changed in
order to support IPv6. A new private data struct
rds6_ib_connect_private is introduced to handle this. To ensure
backward compatibility, an IPv6 capable RDS stack uses another RDMA
listener port (RDS_CM_PORT) to accept IPv6 connection. And it
continues to use the original RDS_PORT for IPv4 RDS connections. When
it needs to communicate with an IPv6 peer, it uses the RDS_CM_PORT to
send the connection set up request.v5: Fixed syntax problem (David Miller).
v4: Changed port history comments in rds.h (Sowmini Varadhan).
v3: Added support to set up IPv4 connection using mapped address
(David Miller).
Added support to set up connection between link local and non-link
addresses.
Various review comments from Santosh Shilimkar and Sowmini Varadhan.v2: Fixed bound and peer address scope mismatched issue.
Added back rds_connect() IPv6 changes.Signed-off-by: Ka-Cheong Poon
Acked-by: Santosh Shilimkar
Signed-off-by: David S. Miller -
This patch changes the internal representation of an IP address to use
struct in6_addr. IPv4 address is stored as an IPv4 mapped address.
All the functions which take an IP address as argument are also
changed to use struct in6_addr. But RDS socket layer is not modified
such that it still does not accept IPv6 address from an application.
And RDS layer does not accept nor initiate IPv6 connections.v2: Fixed sparse warnings.
Signed-off-by: Ka-Cheong Poon
Acked-by: Santosh Shilimkar
Signed-off-by: David S. Miller
15 Jun, 2018
1 commit
-
Loop transport which is self loopback, remote port congestion
update isn't relevant. Infact the xmit path already ignores it.
Receive path needs to do the same.Reported-by: syzbot+4c20b3866171ce8441d2@syzkaller.appspotmail.com
Reviewed-by: Sowmini Varadhan
Signed-off-by: Santosh Shilimkar
Signed-off-by: David S. Miller
03 May, 2018
1 commit
-
syzbot/KMSAN reported an uninit-value in put_cmsg(), originating
from rds_cmsg_recv().Simply clear the structure, since we have holes there, or since
rx_traces might be smaller than RDS_MSG_RX_DGRAM_TRACE_MAX.BUG: KMSAN: uninit-value in copy_to_user include/linux/uaccess.h:184 [inline]
BUG: KMSAN: uninit-value in put_cmsg+0x600/0x870 net/core/scm.c:242
CPU: 0 PID: 4459 Comm: syz-executor582 Not tainted 4.16.0+ #87
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x185/0x1d0 lib/dump_stack.c:53
kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
kmsan_internal_check_memory+0x135/0x1e0 mm/kmsan/kmsan.c:1157
kmsan_copy_to_user+0x69/0x160 mm/kmsan/kmsan.c:1199
copy_to_user include/linux/uaccess.h:184 [inline]
put_cmsg+0x600/0x870 net/core/scm.c:242
rds_cmsg_recv net/rds/recv.c:570 [inline]
rds_recvmsg+0x2db5/0x3170 net/rds/recv.c:657
sock_recvmsg_nosec net/socket.c:803 [inline]
sock_recvmsg+0x1d0/0x230 net/socket.c:810
___sys_recvmsg+0x3fb/0x810 net/socket.c:2205
__sys_recvmsg net/socket.c:2250 [inline]
SYSC_recvmsg+0x298/0x3c0 net/socket.c:2262
SyS_recvmsg+0x54/0x80 net/socket.c:2257
do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x3d/0xa2Fixes: 3289025aedc0 ("RDS: add receive message trace used by application")
Signed-off-by: Eric Dumazet
Reported-by: syzbot
Cc: Santosh Shilimkar
Cc: linux-rdma
Signed-off-by: David S. Miller
08 Mar, 2018
1 commit
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Commit 401910db4cd4 ("rds: deliver zerocopy completion notification
with data") removes support fo r zerocopy completion notification
on the sk_error_queue, thus we no longer need to track the cookie
information in sk_buff structures.This commit removes the struct sk_buff_head rs_zcookie_queue by
a simpler list that results in a smaller memory footprint as well
as more efficient memory_allocation time.Signed-off-by: Sowmini Varadhan
Acked-by: Willem de Bruijn
Signed-off-by: David S. Miller
28 Feb, 2018
1 commit
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This commit is an optimization over commit 01883eda72bd
("rds: support for zcopy completion notification") for PF_RDS sockets.RDS applications are predominantly request-response transactions, so
it is more efficient to reduce the number of system calls and have
zerocopy completion notification delivered as ancillary data on the
POLLIN channel.Cookies are passed up as ancillary data (at level SOL_RDS) in a
struct rds_zcopy_cookies when the returned value of recvmsg() is
greater than, or equal to, 0. A max of RDS_MAX_ZCOOKIES may be passed
with each message.This commit removes support for zerocopy completion notification on
MSG_ERRQUEUE for PF_RDS sockets.Signed-off-by: Sowmini Varadhan
Acked-by: Willem de Bruijn
Acked-by: Santosh Shilimkar
Signed-off-by: David S. Miller
17 Feb, 2018
1 commit
-
RDS removes a datagram (rds_message) from the retransmit queue when
an ACK is received. The ACK indicates that the receiver has queued
the RDS datagram, so that the sender can safely forget the datagram.
When all references to the rds_message are quiesced, rds_message_purge
is called to release resources used by the rds_messageIf the datagram to be removed had pinned pages set up, add
an entry to the rs->rs_znotify_queue so that the notifcation
will be sent up via rds_rm_zerocopy_callback() when the
rds_message is eventually freed by rds_message_purge.rds_rm_zerocopy_callback() attempts to batch the number of cookies
sent with each notification to a max of SO_EE_ORIGIN_MAX_ZCOOKIES.
This is achieved by checking the tail skb in the sk_error_queue:
if this has room for one more cookie, the cookie from the
current notification is added; else a new skb is added to the
sk_error_queue. Every invocation of rds_rm_zerocopy_callback() will
trigger a ->sk_error_report to notify the application.Signed-off-by: Sowmini Varadhan
Acked-by: Santosh Shilimkar
Acked-by: Willem de Bruijn
Signed-off-by: David S. Miller
05 Jul, 2017
1 commit
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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
Signed-off-by: Hans Liljestrand
Signed-off-by: Kees Cook
Signed-off-by: David Windsor
Signed-off-by: David S. Miller
22 Jun, 2017
1 commit
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The RDS handshake ping probe added by commit 5916e2c1554f
("RDS: TCP: Enable multipath RDS for TCP") is sent from rds_sendmsg()
before the first data packet is sent to a peer. If the conversation
is not bidirectional (i.e., one side is always passive and never
invokes rds_sendmsg()) and the passive side restarts its rds_tcp
module, a new HS ping probe needs to be sent, so that the number
of paths can be re-established.This patch achieves that by sending a HS ping probe from
rds_tcp_accept_one() when c_npaths is 0 (i.e., we have not done
a handshake probe with this peer yet).Signed-off-by: Sowmini Varadhan
Tested-by: Jenny Xu
Signed-off-by: David S. Miller
17 Jun, 2017
1 commit
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Found when testing between sparc and x86 machines on different
subnets, so the address comparison patterns hit the corner cases and
brought out some bugs fixed by this patch.Signed-off-by: Sowmini Varadhan
Tested-by: Imanti Mendez
Acked-by: Santosh Shilimkar
Signed-off-by: David S. Miller
22 Apr, 2017
1 commit
03 Jan, 2017
2 commits
-
Socket option to tap receive path latency in various stages
in nano seconds. It can be enabled on selective sockets using
using SO_RDS_MSG_RXPATH_LATENCY socket option. RDS will return
the data to application with RDS_CMSG_RXPATH_LATENCY in defined
format. Scope is left to add more trace points for future
without need of change in the interface.Reviewed-by: Sowmini Varadhan
Signed-off-by: Santosh Shilimkar -
Tracks the receive side memory added to scokets and removed from sockets.
Signed-off-by: Venkat Venkatsubra
Signed-off-by: Santosh Shilimkar
18 Nov, 2016
1 commit
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The RDS transport has to be able to distinguish between
two types of failure events:
(a) when the transport fails (e.g., TCP connection reset)
but the RDS socket/connection layer on both sides stays
the same
(b) when the peer's RDS layer itself resets (e.g., due to module
reload or machine reboot at the peer)
In case (a) both sides must reconnect and continue the RDS messaging
without any message loss or disruption to the message sequence numbers,
and this is achieved by rds_send_path_reset().In case (b) we should reset all rds_connection state to the
new incarnation of the peer. Examples of state that needs to
be reset are next expected rx sequence number from, or messages to be
retransmitted to, the new incarnation of the peer.To achieve this, the RDS handshake probe added as part of
commit 5916e2c1554f ("RDS: TCP: Enable multipath RDS for TCP")
is enhanced so that sender and receiver of the RDS ping-probe
will add a generation number as part of the RDS_EXTHDR_GEN_NUM
extension header. Each peer stores local and remote generation
numbers as part of each rds_connection. Changes in generation
number will be detected via incoming handshake probe ping
request or response and will allow the receiver to reset rds_connection
state.Signed-off-by: Sowmini Varadhan
Acked-by: Santosh Shilimkar
Signed-off-by: David S. Miller
16 Jul, 2016
1 commit
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Use RDS probe-ping to compute how many paths may be used with
the peer, and to synchronously start the multiple paths. If mprds is
supported, hash outgoing traffic to one of multiple paths in rds_sendmsg()
when multipath RDS is supported by the transport.CC: Santosh Shilimkar
Signed-off-by: Sowmini Varadhan
Acked-by: Santosh Shilimkar
Signed-off-by: David S. Miller
02 Jul, 2016
1 commit
-
RDS ping messages are sent with a non-zero src port to a zero
dst port, so that the rds pong messages can be sent back to the
originators src port. However if a confused/malicious sender
sends a ping with a 0 src port, we'd have an infinite ping-pong
loop. To avoid this, the receiver should ignore ping messages
with a 0 src port.Acked-by: Santosh Shilimkar
Signed-off-by: Sowmini Varadhan
Signed-off-by: David S. Miller
15 Jun, 2016
4 commits
-
This commit allows rds_send_pong() callers to send back
the rds pong message on some path other than c_path[0] by
passing in a struct rds_conn_path * argument. It also
removes the last dependency on the #defines in rds_single.h
from send.cSigned-off-by: Sowmini Varadhan
Signed-off-by: David S. Miller -
t_mp_capable transports can use rds_inc_path_init to initialize
all fields in struct rds_incoming, including the i_conn_path.Signed-off-by: Sowmini Varadhan
Signed-off-by: David S. Miller -
Transports that are t_mp_capable should set the rds_conn_path
on which the datagram was recived in the ->i_conn_path field
of struct rds_incoming.Signed-off-by: Sowmini Varadhan
Signed-off-by: David S. Miller -
In preparation for multipath RDS, split the rds_connection
structure into a base structure, and a per-path struct rds_conn_path.
The base structure tracks information and locks common to all
paths. The workqs for send/recv/shutdown etc are tracked per
rds_conn_path. Thus the workq callbacks now work with rds_conn_path.This commit allows for one rds_conn_path per rds_connection, and will
be extended into multiple conn_paths in subsequent commits.Signed-off-by: Sowmini Varadhan
Signed-off-by: David S. Miller
03 Jun, 2016
1 commit
-
The last field "flags" of object "minfo" is not initialized.
Copying this object out may leak kernel stack data.
Assign 0 to it to avoid leak.Signed-off-by: Kangjie Lu
Acked-by: Santosh Shilimkar
Signed-off-by: David S. Miller
03 Mar, 2016
1 commit
-
The SO_TIMESTAMP generates time stamp for each incoming RDS messages
User app can enable it by using SO_TIMESTAMP setsocketopt() at
SOL_SOCKET level. CMSG data of cmsg type SO_TIMESTAMP contains the
time stamp in struct timeval format.Reviewed-by: Sowmini Varadhan
Signed-off-by: Santosh Shilimkar
Signed-off-by: Santosh Shilimkar
Signed-off-by: David S. Miller
03 Mar, 2015
1 commit
-
After TIPC doesn't depend on iocb argument in its internal
implementations of sendmsg() and recvmsg() hooks defined in proto
structure, no any user is using iocb argument in them at all now.
Then we can drop the redundant iocb argument completely from kinds of
implementations of both sendmsg() and recvmsg() in the entire
networking stack.Cc: Christoph Hellwig
Suggested-by: Al Viro
Signed-off-by: Ying Xue
Signed-off-by: David S. Miller
10 Dec, 2014
1 commit
-
Note that the code _using_ ->msg_iter at that point will be very
unhappy with anything other than unshifted iovec-backed iov_iter.
We still need to convert users to proper primitives.Signed-off-by: Al Viro
24 Nov, 2014
1 commit
-
instances get considerably simpler from that...
Signed-off-by: Al Viro
19 Jan, 2014
1 commit
-
This is a follow-up patch to f3d3342602f8bc ("net: rework recvmsg
handler msg_name and msg_namelen logic").DECLARE_SOCKADDR validates that the structure we use for writing the
name information to is not larger than the buffer which is reserved
for msg->msg_name (which is 128 bytes). Also use DECLARE_SOCKADDR
consistently in sendmsg code paths.Signed-off-by: Steffen Hurrle
Suggested-by: Hannes Frederic Sowa
Acked-by: Hannes Frederic Sowa
Signed-off-by: David S. Miller
21 Nov, 2013
1 commit
-
This patch now always passes msg->msg_namelen as 0. recvmsg handlers must
set msg_namelen to the proper size
Suggested-by: Eric Dumazet
Signed-off-by: Hannes Frederic Sowa
Signed-off-by: David S. Miller
23 Jul, 2012
1 commit
-
Jay Fenlason (fenlason@redhat.com) found a bug,
that recvfrom() on an RDS socket can return the contents of random kernel
memory to userspace if it was called with a address length larger than
sizeof(struct sockaddr_in).
rds_recvmsg() also fails to set the addr_len paramater properly before
returning, but that's just a bug.
There are also a number of cases wher recvfrom() can return an entirely bogus
address. Anything in rds_recvmsg() that returns a non-negative value but does
not go through the "sin = (struct sockaddr_in *)msg->msg_name;" code path
at the end of the while(1) loop will return up to 128 bytes of kernel memory
to userspace.And I write two test programs to reproduce this bug, you will see that in
rds_server, fromAddr will be overwritten and the following sock_fd will be
destroyed.
Yes, it is the programmer's fault to set msg_namelen incorrectly, but it is
better to make the kernel copy the real length of address to user space in
such case.How to run the test programs ?
I test them on 32bit x86 system, 3.5.0-rc7.1 compile
gcc -o rds_client rds_client.c
gcc -o rds_server rds_server.c2 run ./rds_server on one console
3 run ./rds_client on another console
4 you will see something like:
server is waiting to receive data...
old socket fd=3
server received data from client:data from client
msg.msg_namelen=32
new socket fd=-1067277685
sendmsg()
: Bad file descriptor/***************** rds_client.c ********************/
int main(void)
{
int sock_fd;
struct sockaddr_in serverAddr;
struct sockaddr_in toAddr;
char recvBuffer[128] = "data from client";
struct msghdr msg;
struct iovec iov;sock_fd = socket(AF_RDS, SOCK_SEQPACKET, 0);
if (sock_fd < 0) {
perror("create socket error\n");
exit(1);
}memset(&serverAddr, 0, sizeof(serverAddr));
serverAddr.sin_family = AF_INET;
serverAddr.sin_addr.s_addr = inet_addr("127.0.0.1");
serverAddr.sin_port = htons(4001);if (bind(sock_fd, (struct sockaddr*)&serverAddr, sizeof(serverAddr)) < 0) {
perror("bind() error\n");
close(sock_fd);
exit(1);
}memset(&toAddr, 0, sizeof(toAddr));
toAddr.sin_family = AF_INET;
toAddr.sin_addr.s_addr = inet_addr("127.0.0.1");
toAddr.sin_port = htons(4000);
msg.msg_name = &toAddr;
msg.msg_namelen = sizeof(toAddr);
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_iov->iov_base = recvBuffer;
msg.msg_iov->iov_len = strlen(recvBuffer) + 1;
msg.msg_control = 0;
msg.msg_controllen = 0;
msg.msg_flags = 0;if (sendmsg(sock_fd, &msg, 0) == -1) {
perror("sendto() error\n");
close(sock_fd);
exit(1);
}printf("client send data:%s\n", recvBuffer);
memset(recvBuffer, '\0', 128);
msg.msg_name = &toAddr;
msg.msg_namelen = sizeof(toAddr);
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_iov->iov_base = recvBuffer;
msg.msg_iov->iov_len = 128;
msg.msg_control = 0;
msg.msg_controllen = 0;
msg.msg_flags = 0;
if (recvmsg(sock_fd, &msg, 0) == -1) {
perror("recvmsg() error\n");
close(sock_fd);
exit(1);
}printf("receive data from server:%s\n", recvBuffer);
close(sock_fd);
return 0;
}/***************** rds_server.c ********************/
int main(void)
{
struct sockaddr_in fromAddr;
int sock_fd;
struct sockaddr_in serverAddr;
unsigned int addrLen;
char recvBuffer[128];
struct msghdr msg;
struct iovec iov;sock_fd = socket(AF_RDS, SOCK_SEQPACKET, 0);
if(sock_fd < 0) {
perror("create socket error\n");
exit(0);
}memset(&serverAddr, 0, sizeof(serverAddr));
serverAddr.sin_family = AF_INET;
serverAddr.sin_addr.s_addr = inet_addr("127.0.0.1");
serverAddr.sin_port = htons(4000);
if (bind(sock_fd, (struct sockaddr*)&serverAddr, sizeof(serverAddr)) < 0) {
perror("bind error\n");
close(sock_fd);
exit(1);
}printf("server is waiting to receive data...\n");
msg.msg_name = &fromAddr;/*
* I add 16 to sizeof(fromAddr), ie 32,
* and pay attention to the definition of fromAddr,
* recvmsg() will overwrite sock_fd,
* since kernel will copy 32 bytes to userspace.
*
* If you just use sizeof(fromAddr), it works fine.
* */
msg.msg_namelen = sizeof(fromAddr) + 16;
/* msg.msg_namelen = sizeof(fromAddr); */
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_iov->iov_base = recvBuffer;
msg.msg_iov->iov_len = 128;
msg.msg_control = 0;
msg.msg_controllen = 0;
msg.msg_flags = 0;while (1) {
printf("old socket fd=%d\n", sock_fd);
if (recvmsg(sock_fd, &msg, 0) == -1) {
perror("recvmsg() error\n");
close(sock_fd);
exit(1);
}
printf("server received data from client:%s\n", recvBuffer);
printf("msg.msg_namelen=%d\n", msg.msg_namelen);
printf("new socket fd=%d\n", sock_fd);
strcat(recvBuffer, "--data from server");
if (sendmsg(sock_fd, &msg, 0) == -1) {
perror("sendmsg()\n");
close(sock_fd);
exit(1);
}
}close(sock_fd);
return 0;
}Signed-off-by: Weiping Pan
Signed-off-by: David S. Miller
