iproute uses too small of a receive buffer

It uses 1MB as receive buf limit by default (without
increasing /proc/sys/net/core/rmem_max it will be limited by less
however) and allows to specify the size manually using "-rcvbuf X"
(-r is already used, so you need to specify at least -rc).

Additionally rtnl_listen() continues on ENOBUFS after printing the
error message.

diff --git a/include/libnetlink.h b/include/libnetlink.h
index 0e0246829867d87564e91d45aa57e5833dc9a268..61da15be2618152714f8ec1781cd438bf382fe57 100644 (file)
--- a/include/libnetlink.h
+++ b/include/libnetlink.h
@@ -17,6 +17,8 @@ struct rtnl_handle
        __u32                   dump;
 };
 
+extern int rcvbuf;
+
 extern int rtnl_open(struct rtnl_handle *rth, unsigned subscriptions);
 extern int rtnl_open_byproto(struct rtnl_handle *rth, unsigned subscriptions, int protocol);
 extern void rtnl_close(struct rtnl_handle *rth);

diff --git a/ip/ip.c b/ip/ip.c
index 2bd54b2aa9058699a3bc4af68398f04c69084690..b4c076aa43570b3e3f8334f5219200fa532086b9 100644 (file)
--- a/ip/ip.c
+++ b/ip/ip.c
@@ -50,7 +50,8 @@ static void usage(void)
 "                   tunnel | maddr | mroute | monitor | xfrm }\n"
 "       OPTIONS := { -V[ersion] | -s[tatistics] | -d[etails] | -r[esolve] |\n"
 "                    -f[amily] { inet | inet6 | ipx | dnet | link } |\n"
-"                    -o[neline] | -t[imestamp] | -b[atch] [filename] }\n");
+"                    -o[neline] | -t[imestamp] | -b[atch] [filename] |\n"
+"                    -rc[vbuf] [size]}\n");
        exit(-1);
 }
 
@@ -213,6 +214,19 @@ int main(int argc, char **argv)
                        if (argc <= 1)
                                usage();
                        batch_file = argv[1];
+               } else if (matches(opt, "-rcvbuf") == 0) {
+                       unsigned int size;
+
+                       argc--;
+                       argv++;
+                       if (argc <= 1)
+                               usage();
+                       if (get_unsigned(&size, argv[1], 0)) {
+                               fprintf(stderr, "Invalid rcvbuf size '%s'\n",
+                                       argv[1]);
+                               exit(-1);
+                       }
+                       rcvbuf = size;
                } else if (matches(opt, "-help") == 0) {
                        usage();
                } else {

diff --git a/lib/libnetlink.c b/lib/libnetlink.c
index 100dd4078a77d1cafaee8d437b8820cc7214667e..a6c030682726cd015497f29928ab47334e246af5 100644 (file)
--- a/lib/libnetlink.c
+++ b/lib/libnetlink.c
@@ -25,6 +25,8 @@
 
 #include "libnetlink.h"
 
+int rcvbuf = 1024 * 1024;
+
 void rtnl_close(struct rtnl_handle *rth)
 {
        if (rth->fd >= 0) {
@@ -38,7 +40,6 @@ int rtnl_open_byproto(struct rtnl_handle *rth, unsigned subscriptions,
 {
        socklen_t addr_len;
        int sndbuf = 32768;
-       int rcvbuf = 32768;
 
        memset(rth, 0, sizeof(*rth));
 
@@ -409,6 +410,8 @@ int rtnl_listen(struct rtnl_handle *rtnl,
                                continue;
                        fprintf(stderr, "netlink receive error %s (%d)\n",
                                strerror(errno), errno);
+                       if (errno == ENOBUFS)
+                               continue;
                        return -1;
                }
                if (status == 0) {