From 7a22821b5870ba543343f0979453298d4acd2ed0 Mon Sep 17 00:00:00 2001
From: Vladimir Dubrovin <3proxy@3proxy.ru>
Date: Mon, 12 Oct 2026 23:08:18 +0300
Subject: [PATCH] Enable auto mode splice by default

---
 man/3proxy.cfg.5 | 8 ++++----
 src/proxymain.c  | 9 +++++----
 src/structures.h | 2 +-
 3 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/man/3proxy.cfg.5 b/man/3proxy.cfg.5
index 34b9e0d..66b4971 100644
--- a/man/3proxy.cfg.5
+++ b/man/3proxy.cfg.5
@@ -208,12 +208,12 @@ it pays: a body of known length if at least 16K of it is left to read, a stream
 once it carries large reads, back to copying when they turn small. \fB-s1\fR always
 splices what the server sends to the client (downloads), \fB-s2\fR what the client
 sends (uploads), \fB-s3\fR both; adding 4 (\fB-s5\fR, \fB-s6\fR, \fB-s7\fR, the last the same as
-\fB-s\fR) splices those directions only where it pays. \fB-s0\fR, the default, turns it
+\fB-s\fR, and the default) splices those directions only where it pays. \fB-s0\fR turns it
 off. splice() suits large transfers: they go faster and use less CPU; small
 requests go slower with it. A spliced direction needs a pipe (two file
 descriptors), made when first needed and kept for the connection, and more
-kernel memory; data filters are not applied to spliced data. Available in builds
-with WITHSPLICE, the default on Linux.
+kernel memory. A service with data filters does not splice, so that the filters
+see all of the data. Available in builds with WITHSPLICE, the default on Linux.
 .br
 .B -C
  (for TCP services) a connection closed by any of the sides terminates the
@@ -1458,7 +1458,7 @@ as
 data filtering will be performed through filtering plugins to avoid data
 corruption and/or Content-Length changing. A body up to this size is read
 whole into memory and filtered at once. 0 removes the limit, but then a body
-is only filtered whole if it fits in the connection's 32K buffer.
+is only filtered whole if it fits in the connection's 16K buffer.
 Default is 1MB (1048576).
 
 .SH SSL/TLS SUPPORT
diff --git a/src/proxymain.c b/src/proxymain.c
index c81ad32..f33eed9 100644
--- a/src/proxymain.c
+++ b/src/proxymain.c
@@ -434,8 +434,8 @@ static int srvprepare(struct srvstart *s, int argc, char **argv){
 #endif
 #ifdef WITHSPLICE
 	" -s[N] Use splice(): -s1 server to client, -s2 client to server, -s3 both\n"
-	"  directions; -s (-s7) both, -s5 or -s6 one, only where it pays (large\n"
-	"  transfers) - no filtering for data, off by default\n"
+	"  directions; -s (-s7, the default) both, -s5 or -s6 one, only where it\n"
+	"  pays (large transfers); -s0 never. Not with data filters\n"
 	" -C connection closed by any of the sides terminates the session, by default\n"
 	"    the session is kept until both sides close it (TCP half-close)\n"
 	" -U(0-3) (for socks) what to do when the destination changes within an UDP\n"
@@ -446,7 +446,7 @@ static int srvprepare(struct srvstart *s, int argc, char **argv){
 	" -fFORMAT logging format (see documentation)\n"
 	" -l log to stderr\n"
 	" -lFILENAME log to FILENAME\n"
-	" -b(BUFSIZE) size of network buffer, at most and by default 32768\n"
+	" -b(BUFSIZE) size of network buffer, at most and by default 16384\n"
 	" -S(STACKSIZE) value to add to default client thread stack size\n"
 	" -t be silent (do not log service start/stop)\n"
 	"\n"
@@ -1490,7 +1490,8 @@ void srvinit(struct srvparam * srv, struct clientparam *param){
  srv->i_nsfd = srv->o_nsfd = -1;
 #endif
 #ifdef WITHSPLICE
- srv->usesplice = 0;
+ /* where it pays: large transfers, -s0 to never */
+ srv->usesplice = SPLICE_DOWNLOAD|SPLICE_UPLOAD|SPLICE_AUTO;
 #endif
  srv->halfclose = 1;
  srv->udpauth = 3;
diff --git a/src/structures.h b/src/structures.h
index e1470d9..56b913f 100644
--- a/src/structures.h
+++ b/src/structures.h
@@ -199,7 +199,7 @@ int
 
 #define MAX_HASH_SIZE (64)
 #define UDPBUFSIZE 16384
-#define CLIENTBUFSIZE 32768
+#define CLIENTBUFSIZE (16384 + 64)
 #define CLIENTTMPBUFSIZE 8192
 #define HOSTNAMELEN 256
 #define USERNAMELEN 128