congestion.diff

   1 From: Dave Taht <d@taht.net>
   2
   3 In the bufferbloat age, anything that can make for a kinder, gentler bulk
   4 transfer protocol seems desirable.
   5
   6 This add support for user and server selectable congestion control algorithms.
   7
   8 For example:
   9     --congestion-alg=lp # For the tcp-lp algorithm on the command line
  10
  11 And diffserv support:
  12     --diffserv=8 for setting the CS1 bit
  13
  14 Also available in rsync daemon modules:
  15
  16 [mystuff]
  17     congestion alg = westwood # for a wireless connection
  18     diffserv = 8
  19
  20 This could be improved by being able to specify a list of congestion algorithms
  21 to try, symbolic names for diffserv (CS1), a better name than 'congestion-alg',
  22 and some error checking.
  23
  24 To use this patch, run these commands for a successful build:
  25
  26     patch -p1 <patches/congestion.diff
  27     ./configure                         (optional if already run)
  28     make
  29
  30 based-on: d1a1fec1340254926e17f5d83f848f7574286a33
  31 diff --git a/loadparm.c b/loadparm.c
  32 --- a/loadparm.c
  33 +++ b/loadparm.c
  34 @@ -109,6 +109,7 @@ typedef struct {
  35         char *auth_users;
  36         char *charset;
  37         char *comment;
  38 +       char *congestion_alg;
  39         char *dont_compress;
  40         char *exclude;
  41         char *exclude_from;
  42 @@ -134,6 +135,7 @@ typedef struct {
  43  /* NOTE: update this macro if the last char* variable changes! */
  44  #define LOCAL_STRING_COUNT() (offsetof(local_vars, uid) / sizeof (char*) + 1)
  45
  46 +       int diffserv;
  47         int max_connections;
  48         int max_verbosity;
  49         int syslog_facility;
  50 @@ -185,6 +187,7 @@ static const all_vars Defaults = {
  51   /* auth_users; */             NULL,
  52   /* charset; */                NULL,
  53   /* comment; */                NULL,
  54 + /* congestion_alg; */                 NULL,
  55   /* dont_compress; */          DEFAULT_DONT_COMPRESS,
  56   /* exclude; */                        NULL,
  57   /* exclude_from; */           NULL,
  58 @@ -208,6 +211,7 @@ static const all_vars Defaults = {
  59   /* temp_dir; */               NULL,
  60   /* uid; */                    NULL,
  61
  62 + /* diffserv; */               8,
  63   /* max_connections; */                0,
  64   /* max_verbosity; */          1,
  65   /* syslog_facility; */                LOG_DAEMON,
  66 @@ -322,6 +326,8 @@ static struct parm_struct parm_table[] =
  67   {"auth users",        P_STRING, P_LOCAL, &Vars.l.auth_users,          NULL,0},
  68   {"charset",           P_STRING, P_LOCAL, &Vars.l.charset,             NULL,0},
  69   {"comment",           P_STRING, P_LOCAL, &Vars.l.comment,             NULL,0},
  70 + {"congestion alg",    P_STRING, P_LOCAL, &Vars.l.congestion_alg,      NULL,0},
  71 + {"diffserv",          P_INTEGER,P_LOCAL, &Vars.l.diffserv,            NULL,0},
  72   {"dont compress",     P_STRING, P_LOCAL, &Vars.l.dont_compress,       NULL,0},
  73   {"exclude from",      P_STRING, P_LOCAL, &Vars.l.exclude_from,        NULL,0},
  74   {"exclude",           P_STRING, P_LOCAL, &Vars.l.exclude,             NULL,0},
  75 @@ -454,6 +460,7 @@ FN_GLOBAL_INTEGER(lp_rsync_port, &Vars.g.rsync_port)
  76  FN_LOCAL_STRING(lp_auth_users, auth_users)
  77  FN_LOCAL_STRING(lp_charset, charset)
  78  FN_LOCAL_STRING(lp_comment, comment)
  79 +FN_LOCAL_STRING(lp_congestion_alg, congestion_alg)
  80  FN_LOCAL_STRING(lp_dont_compress, dont_compress)
  81  FN_LOCAL_STRING(lp_exclude, exclude)
  82  FN_LOCAL_STRING(lp_exclude_from, exclude_from)
  83 @@ -477,6 +484,7 @@ FN_LOCAL_STRING(lp_secrets_file, secrets_file)
  84  FN_LOCAL_STRING(lp_temp_dir, temp_dir)
  85  FN_LOCAL_STRING(lp_uid, uid)
  86
  87 +FN_LOCAL_INTEGER(lp_diffserv, diffserv)
  88  FN_LOCAL_INTEGER(lp_max_connections, max_connections)
  89  FN_LOCAL_INTEGER(lp_max_verbosity, max_verbosity)
  90  FN_LOCAL_INTEGER(lp_syslog_facility, syslog_facility)
  91 diff --git a/options.c b/options.c
  92 --- a/options.c
  93 +++ b/options.c
  94 @@ -71,6 +71,8 @@ int delete_during = 0;
  95  int delete_before = 0;
  96  int delete_after = 0;
  97  int delete_excluded = 0;
  98 +int diffserv = 8;
  99 +char *congestion_alg = NULL;
 100  int remove_source_files = 0;
 101  int one_file_system = 0;
 102  int protocol_version = PROTOCOL_VERSION;
 103 @@ -780,6 +782,8 @@ void usage(enum logcode F)
 104    rprintf(F,"     --address=ADDRESS       bind address for outgoing socket to daemon\n");
 105    rprintf(F,"     --port=PORT             specify double-colon alternate port number\n");
 106    rprintf(F,"     --sockopts=OPTIONS      specify custom TCP options\n");
 107 +  rprintf(F,"     --diffserv=[0-63]       specify diffserv setting \n");
 108 +  rprintf(F,"     --congestion-alg=STRING choose a congestion algo\n");
 109    rprintf(F,"     --blocking-io           use blocking I/O for the remote shell\n");
 110    rprintf(F,"     --stats                 give some file-transfer stats\n");
 111    rprintf(F," -8, --8-bit-output          leave high-bit chars unescaped in output\n");
 112 @@ -1041,6 +1045,8 @@ static struct poptOption long_options[] = {
 113  #endif
 114    {"remote-option",   'M', POPT_ARG_STRING, 0, 'M', 0, 0 },
 115    {"protocol",         0,  POPT_ARG_INT,    &protocol_version, 0, 0, 0 },
 116 +  {"congestion-alg",   0,  POPT_ARG_STRING, &congestion_alg, 0, 0, 0 },
 117 +  {"diffserv",         0,  POPT_ARG_INT,    &diffserv, 0, 0, 0 },
 118    {"checksum-seed",    0,  POPT_ARG_INT,    &checksum_seed, 0, 0, 0 },
 119    {"server",           0,  POPT_ARG_NONE,   0, OPT_SERVER, 0, 0 },
 120    {"sender",           0,  POPT_ARG_NONE,   0, OPT_SENDER, 0, 0 },
 121 @@ -1068,6 +1074,8 @@ static void daemon_usage(enum logcode F)
 122    rprintf(F,"     --log-file=FILE         override the \"log file\" setting\n");
 123    rprintf(F,"     --log-file-format=FMT   override the \"log format\" setting\n");
 124    rprintf(F,"     --sockopts=OPTIONS      specify custom TCP options\n");
 125 +  rprintf(F,"     --diffserv=[0-63]       specify diffserv setting \n");
 126 +  rprintf(F,"     --congestion-alg=STRING choose a congestion algo\n");
 127    rprintf(F," -v, --verbose               increase verbosity\n");
 128    rprintf(F," -4, --ipv4                  prefer IPv4\n");
 129    rprintf(F," -6, --ipv6                  prefer IPv6\n");
 130 diff --git a/socket.c b/socket.c
 131 --- a/socket.c
 132 +++ b/socket.c
 133 @@ -38,6 +38,8 @@ extern char *bind_address;
 134  extern char *sockopts;
 135  extern int default_af_hint;
 136  extern int connect_timeout;
 137 +extern int diffserv;
 138 +extern char *congestion_alg;
 139
 140  #ifdef HAVE_SIGACTION
 141  static struct sigaction sigact;
 142 @@ -166,6 +168,37 @@ static void contimeout_handler(UNUSED(int val))
 143         connect_timeout = -1;
 144  }
 145
 146 +/* Set special socket options
 147 + *
 148 + * Diffserv is a value in the range of 0-63, and needs to be shifted left
 149 + *          2 places AND treated differently for ipv4 and ipv6.
 150 + * Setting TCP congestion control is rather Linux specific (at the moment)
 151 + * and sends a varying length string to setsockopt rather than an integer
 152 + * or character.
 153 +*/
 154 +
 155 +void set_special_sockopts(int s)
 156 +{
 157 +#if defined(TCP_CONGESTION)
 158 +       if (congestion_alg) {
 159 +               if (setsockopt(s, SOL_TCP, TCP_CONGESTION, congestion_alg, strlen(congestion_alg)) == -1)
 160 +                       rprintf(FINFO, "Couldn't set %s congestion algorithm\n", congestion_alg);
 161 +       }
 162 +#endif
 163 +
 164 +/* setting the diffserv/tos bits is different on ipv6 and
 165 + *  ipv4, so we just hammer down on both and ignore the result
 166 + *  And ipv6 demands an int for v. I didn't write the spec.
 167 + */
 168 +       if (diffserv) {
 169 +               int v = (diffserv & 63) <<2;
 170 +               setsockopt(s,IPPROTO_IP, IP_TOS, &v, sizeof(v));
 171 +#if defined(IPV6_TCLASS)
 172 +               setsockopt(s,IPPROTO_IPV6, IPV6_TCLASS, &v, sizeof(v));
 173 +#endif
 174 +       }
 175 +}
 176 +
 177  /* Open a socket to a tcp remote host with the specified port.
 178   *
 179   * Based on code from Warren.  Proxy support by Stephen Rothwell.
 180 @@ -275,6 +308,7 @@ int open_socket_out(char *host, int port, const char *bind_addr,
 181                         alarm(connect_timeout);
 182                 }
 183
 184 +               set_special_sockopts(s);
 185                 set_socket_options(s, sockopts);
 186                 while (connect(s, res->ai_addr, res->ai_addrlen) < 0) {
 187                         if (connect_timeout < 0)
 188 @@ -449,6 +483,7 @@ static int *open_socket_in(int type, int port, const char *bind_addr,
 189                         continue;
 190                 }
 191
 192 +               set_special_sockopts(s);
 193                 setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
 194                            (char *)&one, sizeof one);
 195                 if (sockopts)