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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:18:56 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:18:56 +0000 |
commit | b7c15c31519dc44c1f691e0466badd556ffe9423 (patch) | |
tree | f944572f288bab482a615e09af627d9a2b6727d8 /src/util/inet_windowsize.c | |
parent | Initial commit. (diff) | |
download | postfix-b7c15c31519dc44c1f691e0466badd556ffe9423.tar.xz postfix-b7c15c31519dc44c1f691e0466badd556ffe9423.zip |
Adding upstream version 3.7.10.upstream/3.7.10
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/util/inet_windowsize.c')
-rw-r--r-- | src/util/inet_windowsize.c | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/src/util/inet_windowsize.c b/src/util/inet_windowsize.c new file mode 100644 index 0000000..e982149 --- /dev/null +++ b/src/util/inet_windowsize.c @@ -0,0 +1,82 @@ +/*++ +/* NAME +/* inet_windowsize 3 +/* SUMMARY +/* TCP window scaling control +/* SYNOPSIS +/* #include <iostuff.h> +/* +/* int inet_windowsize; +/* +/* void set_inet_windowsize(sock, windowsize) +/* int sock; +/* int windowsize; +/* DESCRIPTION +/* set_inet_windowsize() overrides the default TCP window size +/* with the specified value. When called before listen() or +/* accept(), this works around broken infrastructure that +/* mis-handles TCP window scaling options. +/* +/* The global inet_windowsize variable is available for other +/* routines to remember that they wish to override the default +/* TCP window size. The variable is not accessed by the +/* set_inet_windowsize() function itself. +/* +/* Arguments: +/* .IP sock +/* TCP communication endpoint, before the connect(2) or listen(2) call. +/* .IP windowsize +/* The preferred TCP window size. This must be > 0. +/* DIAGNOSTICS +/* Panic: interface violation. +/* Warnings: some error return from setsockopt(). +/* LICENSE +/* .ad +/* .fi +/* The Secure Mailer license must be distributed with this software. +/* AUTHOR(S) +/* Wietse Venema +/* IBM T.J. Watson Research +/* P.O. Box 704 +/* Yorktown Heights, NY 10598, USA +/*--*/ + +/* System libraries. */ + +#include <sys_defs.h> +#include <sys/socket.h> + +/* Utility library. */ + +#include <msg.h> +#include <iostuff.h> + +/* Application storage. */ + + /* + * Tunable to work around broken routers. + */ +int inet_windowsize = 0; + +/* set_inet_windowsize - set TCP send/receive window size */ + +void set_inet_windowsize(int sock, int windowsize) +{ + + /* + * Sanity check. + */ + if (windowsize <= 0) + msg_panic("inet_windowsize: bad window size %d", windowsize); + + /* + * Generic implementation: set the send and receive buffer size before + * listen() or connect(). + */ + if (setsockopt(sock, SOL_SOCKET, SO_SNDBUF, (void *) &windowsize, + sizeof(windowsize)) < 0) + msg_warn("setsockopt SO_SNDBUF %d: %m", windowsize); + if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF, (void *) &windowsize, + sizeof(windowsize)) < 0) + msg_warn("setsockopt SO_RCVBUF %d: %m", windowsize); +} |