Re: [PATCH] make _minimum_ TCP retransmission timeout configurable take 2
From: David Miller <davem@davemloft.net>
Date: 2007-08-31 18:57:07
From: Rick Jones <redacted> Date: Fri, 31 Aug 2007 11:11:37 -0700
At the risk of showing my ignorance (what me worry about that?-) I presume this is then an interface expecting to take-in jiffies? That means the user has to know the value of HZ which can be (IIRC) one of three different values?
The iproute2 changes might look something like this:
--- ./include/linux/rtnetlink.h.orig 2007-08-31 11:55:30.000000000 -0700
+++ ./include/linux/rtnetlink.h 2007-08-31 11:52:22.000000000 -0700@@ -351,6 +351,8 @@ enum #define RTAX_INITCWND RTAX_INITCWND RTAX_FEATURES, #define RTAX_FEATURES RTAX_FEATURES + RTAX_RTO_MIN, +#define RTAX_RTO_MIN RTAX_RTO_MIN __RTAX_MAX }; --- ./ip/iproute.c.orig 2007-08-31 11:55:30.000000000 -0700 +++ ./ip/iproute.c 2007-08-31 11:53:29.000000000 -0700
@@ -51,6 +51,7 @@ static const char *mx_names[RTAX_MAX+1] [RTAX_HOPLIMIT] = "hoplimit", [RTAX_INITCWND] = "initcwnd", [RTAX_FEATURES] = "features", + [RTAX_RTO_MIN] = "rto_min", }; static void usage(void) __attribute__((noreturn));
@@ -74,6 +75,7 @@ static void usage(void) fprintf(stderr, " [ rtt NUMBER ] [ rttvar NUMBER ]\n"); fprintf(stderr, " [ window NUMBER] [ cwnd NUMBER ] [ initcwnd NUMBER ]\n"); fprintf(stderr, " [ ssthresh NUMBER ] [ realms REALM ]\n"); + fprintf(stderr, " [ rto_min NUMBER ]\n"); fprintf(stderr, "TYPE := [ unicast | local | broadcast | multicast | throw |\n"); fprintf(stderr, " unreachable | prohibit | blackhole | nat ]\n"); fprintf(stderr, "TABLE_ID := [ local | main | default | all | NUMBER ]\n");
@@ -520,7 +522,8 @@ int print_route(const struct sockaddr_nl if (mxlock & (1<<i)) fprintf(fp, " lock"); - if (i != RTAX_RTT && i != RTAX_RTTVAR) + if (i != RTAX_RTT && i != RTAX_RTTVAR && + i != RTAX_RTO_MIN) fprintf(fp, " %u", *(unsigned*)RTA_DATA(mxrta[i])); else { unsigned val = *(unsigned*)RTA_DATA(mxrta[i]);
@@ -528,7 +531,7 @@ int print_route(const struct sockaddr_nl val *= 1000; if (i == RTAX_RTT) val /= 8; - else + else if (i == RTAX_RTTVAR) val /= 4; if (val >= hz) fprintf(fp, " %ums", val/hz);
@@ -803,6 +806,15 @@ int iproute_modify(int cmd, unsigned fla if (get_unsigned(&rtt, *argv, 0)) invarg("\"rtt\" value is invalid\n", *argv); rta_addattr32(mxrta, sizeof(mxbuf), RTAX_RTT, rtt); + } else if (strcmp(*argv, "rto_min") == 0) { + unsigned rto_min; + NEXT_ARG(); + mxlock |= (1<<RTAX_RTO_MIN); + if (get_unsigned(&rto_min, *argv, 0)) + invarg("\"rto_min\" value is invalid\n", + *argv); + rta_addattr32(mxrta, sizeof(mxbuf), RTAX_RTO_MIN, + rto_min); } else if (matches(*argv, "window") == 0) { unsigned win; NEXT_ARG();