From: Dave Taht <d@taht.net>
In the bufferbloat age, anything that can make for a kinder, gentler bulk
transfer protocol seems desirable.
This add support for user and server selectable congestion control algorithms.
For example:
--congestion-alg=lp # For the tcp-lp algorithm on the command line
And diffserv support:
--diffserv=8 for setting the CS1 bit
Also available in rsync daemon modules:
[mystuff]
congestion alg = westwood # for a wireless connection
diffserv = 8
This could be improved by being able to specify a list of congestion algorithms
to try, symbolic names for diffserv (CS1), a better name than 'congestion-alg',
and some error checking.
To use this patch, run these commands for a successful build:
patch -p1 <patches/congestion.diff
./configure (optional if already run)
make
based-on: d73762eea3f15f2c56bb3fa9394ad1883c25c949
diff --git a/loadparm.c b/loadparm.c
--- a/loadparm.c
+++ b/loadparm.c
@@ -112,6 +112,7 @@ typedef struct {
char *auth_users;
char *charset;
char *comment;
+ char *congestion_alg;
char *dont_compress;
char *exclude;
char *exclude_from;
@@ -138,6 +139,7 @@ typedef struct {
/* NOTE: update this macro if the last char* variable changes! */
#define LOCAL_STRING_COUNT() (offsetof(local_vars, uid) / sizeof (char*) + 1)
+ int diffserv;
int max_connections;
int max_verbosity;
int syslog_facility;
@@ -192,6 +194,7 @@ static const all_vars Defaults = {
/* auth_users; */ NULL,
/* charset; */ NULL,
/* comment; */ NULL,
+ /* congestion_alg; */ NULL,
/* dont_compress; */ DEFAULT_DONT_COMPRESS,
/* exclude; */ NULL,
/* exclude_from; */ NULL,
@@ -216,6 +219,7 @@ static const all_vars Defaults = {
/* temp_dir; */ NULL,
/* uid; */ NULL,
+ /* diffserv; */ 8,
/* max_connections; */ 0,
/* max_verbosity; */ 1,
/* syslog_facility; */ LOG_DAEMON,
@@ -333,6 +337,8 @@ static struct parm_struct parm_table[] =
{"auth users", P_STRING, P_LOCAL, &Vars.l.auth_users, NULL,0},
{"charset", P_STRING, P_LOCAL, &Vars.l.charset, NULL,0},
{"comment", P_STRING, P_LOCAL, &Vars.l.comment, NULL,0},
+ {"congestion alg", P_STRING, P_LOCAL, &Vars.l.congestion_alg, NULL,0},
+ {"diffserv", P_INTEGER,P_LOCAL, &Vars.l.diffserv, NULL,0},
{"dont compress", P_STRING, P_LOCAL, &Vars.l.dont_compress, NULL,0},
{"exclude from", P_STRING, P_LOCAL, &Vars.l.exclude_from, NULL,0},
{"exclude", P_STRING, P_LOCAL, &Vars.l.exclude, NULL,0},
@@ -469,6 +475,7 @@ FN_GLOBAL_INTEGER(lp_rsync_port, &Vars.g.rsync_port)
FN_LOCAL_STRING(lp_auth_users, auth_users)
FN_LOCAL_STRING(lp_charset, charset)
FN_LOCAL_STRING(lp_comment, comment)
+FN_LOCAL_STRING(lp_congestion_alg, congestion_alg)
FN_LOCAL_STRING(lp_dont_compress, dont_compress)
FN_LOCAL_STRING(lp_exclude, exclude)
FN_LOCAL_STRING(lp_exclude_from, exclude_from)
@@ -493,6 +500,7 @@ FN_LOCAL_STRING(lp_syslog_tag, syslog_tag)
FN_LOCAL_STRING(lp_temp_dir, temp_dir)
FN_LOCAL_STRING(lp_uid, uid)
+FN_LOCAL_INTEGER(lp_diffserv, diffserv)
FN_LOCAL_INTEGER(lp_max_connections, max_connections)
FN_LOCAL_INTEGER(lp_max_verbosity, max_verbosity)
FN_LOCAL_INTEGER(lp_syslog_facility, syslog_facility)
diff --git a/options.c b/options.c
--- a/options.c
+++ b/options.c
@@ -71,6 +71,8 @@ int delete_during = 0;
int delete_before = 0;
int delete_after = 0;
int delete_excluded = 0;
+int diffserv = 8;
+char *congestion_alg = NULL;
int remove_source_files = 0;
int one_file_system = 0;
int protocol_version = PROTOCOL_VERSION;
@@ -780,6 +782,8 @@ void usage(enum logcode F)
rprintf(F," --address=ADDRESS bind address for outgoing socket to daemon\n");
rprintf(F," --port=PORT specify double-colon alternate port number\n");
rprintf(F," --sockopts=OPTIONS specify custom TCP options\n");
+ rprintf(F," --diffserv=[0-63] specify diffserv setting \n");
+ rprintf(F," --congestion-alg=STRING choose a congestion algo\n");
rprintf(F," --blocking-io use blocking I/O for the remote shell\n");
rprintf(F," --stats give some file-transfer stats\n");
rprintf(F," -8, --8-bit-output leave high-bit chars unescaped in output\n");
@@ -1041,6 +1045,8 @@ static struct poptOption long_options[] = {
#endif
{"remote-option", 'M', POPT_ARG_STRING, 0, 'M', 0, 0 },
{"protocol", 0, POPT_ARG_INT, &protocol_version, 0, 0, 0 },
+ {"congestion-alg", 0, POPT_ARG_STRING, &congestion_alg, 0, 0, 0 },
+ {"diffserv", 0, POPT_ARG_INT, &diffserv, 0, 0, 0 },
{"checksum-seed", 0, POPT_ARG_INT, &checksum_seed, 0, 0, 0 },
{"server", 0, POPT_ARG_NONE, 0, OPT_SERVER, 0, 0 },
{"sender", 0, POPT_ARG_NONE, 0, OPT_SENDER, 0, 0 },
@@ -1068,6 +1074,8 @@ static void daemon_usage(enum logcode F)
rprintf(F," --log-file=FILE override the \"log file\" setting\n");
rprintf(F," --log-file-format=FMT override the \"log format\" setting\n");
rprintf(F," --sockopts=OPTIONS specify custom TCP options\n");
+ rprintf(F," --diffserv=[0-63] specify diffserv setting \n");
+ rprintf(F," --congestion-alg=STRING choose a congestion algo\n");
rprintf(F," -v, --verbose increase verbosity\n");
rprintf(F," -4, --ipv4 prefer IPv4\n");
rprintf(F," -6, --ipv6 prefer IPv6\n");
diff --git a/socket.c b/socket.c
--- a/socket.c
+++ b/socket.c
@@ -38,6 +38,8 @@ extern char *bind_address;
extern char *sockopts;
extern int default_af_hint;
extern int connect_timeout;
+extern int diffserv;
+extern char *congestion_alg;
#ifdef HAVE_SIGACTION
static struct sigaction sigact;
@@ -166,6 +168,37 @@ static void contimeout_handler(UNUSED(int val))
connect_timeout = -1;
}
+/* Set special socket options
+ *
+ * Diffserv is a value in the range of 0-63, and needs to be shifted left
+ * 2 places AND treated differently for ipv4 and ipv6.
+ * Setting TCP congestion control is rather Linux specific (at the moment)
+ * and sends a varying length string to setsockopt rather than an integer
+ * or character.
+*/
+
+void set_special_sockopts(int s)
+{
+#if defined(TCP_CONGESTION)
+ if (congestion_alg) {
+ if (setsockopt(s, SOL_TCP, TCP_CONGESTION, congestion_alg, strlen(congestion_alg)) == -1)
+ rprintf(FINFO, "Couldn't set %s congestion algorithm\n", congestion_alg);
+ }
+#endif
+
+/* setting the diffserv/tos bits is different on ipv6 and
+ * ipv4, so we just hammer down on both and ignore the result
+ * And ipv6 demands an int for v. I didn't write the spec.
+ */
+ if (diffserv) {
+ int v = (diffserv & 63) <<2;
+ setsockopt(s,IPPROTO_IP, IP_TOS, &v, sizeof(v));
+#if defined(IPV6_TCLASS)
+ setsockopt(s,IPPROTO_IPV6, IPV6_TCLASS, &v, sizeof(v));
+#endif
+ }
+}
+
/* Open a socket to a tcp remote host with the specified port.
*
* Based on code from Warren. Proxy support by Stephen Rothwell.
@@ -275,6 +308,7 @@ int open_socket_out(char *host, int port, const char *bind_addr,
alarm(connect_timeout);
}
+ set_special_sockopts(s);
set_socket_options(s, sockopts);
while (connect(s, res->ai_addr, res->ai_addrlen) < 0) {
if (connect_timeout < 0)
@@ -449,6 +483,7 @@ static int *open_socket_in(int type, int port, const char *bind_addr,
continue;
}
+ set_special_sockopts(s);
setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
(char *)&one, sizeof one);
if (sockopts)
diff -Nurp a/proto.h b/proto.h
--- a/proto.h
+++ b/proto.h
@@ -201,6 +201,7 @@ int lp_rsync_port(void);
char *lp_auth_users(int module_id);
char *lp_charset(int module_id);
char *lp_comment(int module_id);
+char *lp_congestion_alg(int module_id);
char *lp_dont_compress(int module_id);
char *lp_exclude(int module_id);
char *lp_exclude_from(int module_id);
@@ -224,6 +225,7 @@ char *lp_secrets_file(int module_id);
char *lp_syslog_tag(int module_id);
char *lp_temp_dir(int module_id);
char *lp_uid(int module_id);
+int lp_diffserv(int module_id);
int lp_max_connections(int module_id);
int lp_max_verbosity(int module_id);
int lp_syslog_facility(int module_id);
@@ -311,6 +313,7 @@ void successful_send(int ndx);
void send_files(int f_in, int f_out);
int try_bind_local(int s, int ai_family, int ai_socktype,
const char *bind_addr);
+void set_special_sockopts(int s);
int open_socket_out(char *host, int port, const char *bind_addr,
int af_hint);
int open_socket_out_wrapped(char *host, int port, const char *bind_addr,