Example of how to use the default bind to interface option for tasks and
correlate with VRF devices.
Signed-off-by: David Ahern <d...@cumulusnetworks.com>
---
tools/net/Makefile | 6 +-
tools/net/chvrf.c | 225 +++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 229 insertions(+), 2 deletions(-)
create mode 100644 tools/net/chvrf.c
diff --git a/tools/net/Makefile b/tools/net/Makefile
index ee577ea03ba5..c13f11f5637a 100644
--- a/tools/net/Makefile
+++ b/tools/net/Makefile
@@ -10,7 +10,7 @@ YACC = bison
%.lex.c: %.l
$(LEX) -o $@ $<
-all : bpf_jit_disasm bpf_dbg bpf_asm
+all : bpf_jit_disasm bpf_dbg bpf_asm chvrf
bpf_jit_disasm : CFLAGS = -Wall -O2 -DPACKAGE='bpf_jit_disasm'
bpf_jit_disasm : LDLIBS = -lopcodes -lbfd -ldl
@@ -25,8 +25,10 @@ bpf_asm : LDLIBS =
bpf_asm : bpf_asm.o bpf_exp.yacc.o bpf_exp.lex.o
bpf_exp.lex.o : bpf_exp.yacc.c
+chvrf : CFLAGS = -Wall -O2
+
clean :
- rm -rf *.o bpf_jit_disasm bpf_dbg bpf_asm bpf_exp.yacc.* bpf_exp.lex.*
+ rm -rf *.o bpf_jit_disasm bpf_dbg bpf_asm bpf_exp.yacc.* bpf_exp.lex.*
chvrf
install :
install bpf_jit_disasm $(prefix)/bin/bpf_jit_disasm
diff --git a/tools/net/chvrf.c b/tools/net/chvrf.c
new file mode 100644
index 000000000000..71cc925fd101
--- /dev/null
+++ b/tools/net/chvrf.c
@@ -0,0 +1,225 @@
+/*
+ * chvrf.c - Example of how to use the default bind-to-device option for
+ * tasks and correlate to VRFs via the VRF device.
+ *
+ * Copyright (c) 2015 Cumulus Networks
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+#include <sys/ioctl.h>
+#include <sys/prctl.h>
+#include <sys/socket.h>
+#include <signal.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <netinet/in.h>
+#include <net/if.h> /* for struct ifreq */
+#include <libgen.h>
+#include <errno.h>
+
+#ifndef PR_SET_SK_BIND_DEV_IF
+#define PR_SET_SK_BIND_DEV_IF 47
+#endif
+#ifndef PR_GET_SK_BIND_DEV_IF
+#define PR_GET_SK_BIND_DEV_IF 48
+#endif
+
+static int vrf_to_device(int vrf)
+{
+ struct ifreq ifdata;
+ int sd, rc;
+
+ memset(&ifdata, 0, sizeof(ifdata));
+ snprintf(ifdata.ifr_name, sizeof(ifdata.ifr_name) - 1, "vrf%d", vrf);
+
+ sd = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
+ if (sd < 0) {
+ perror("socket failed");
+ return -1;
+ }
+
+ /* Get the index for the specified interface */
+ rc = ioctl(sd, SIOCGIFINDEX, (char *)&ifdata);
+ close(sd);
+ if (rc != 0) {
+ perror("ioctl(SIOCGIFINDEX) failed");
+ return -1;
+ }
+
+ return ifdata.ifr_ifindex;
+}
+
+static int device_to_vrf(int idx)
+{
+ struct ifreq ifdata;
+ int sd, vrf, rc;
+
+ memset(&ifdata, 0, sizeof(ifdata));
+ ifdata.ifr_ifindex = idx;
+
+ sd = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
+ if (sd < 0) {
+ perror("socket failed");
+ return -1;
+ }
+
+ /* Get the index for the specified interface */
+ rc = ioctl(sd, SIOCGIFNAME, (char *)&ifdata);
+ close(sd);
+ if (rc != 0) {
+ perror("ioctl(SIOCGIFNAME) failed");
+ return -1;
+ }
+
+ if (sscanf(ifdata.ifr_name, "vrf%d", &vrf) != 1) {
+ fprintf(stderr, "Unexpected device name (%s)\n",
ifdata.ifr_name);
+ vrf = -1;
+ }
+
+ return vrf;
+}
+
+static int set_vrf(int vrf)
+{
+ int idx;
+ long err;
+
+ /* convert vrf to device index */
+ idx = vrf_to_device(vrf);
+ if (idx < 0) {
+ fprintf(stderr, "Failed to get device index for vrf %d\n", vrf);
+ return -1;
+ }
+
+ /* set default device bind */
+ err = prctl(PR_SET_SK_BIND_DEV_IF, idx);
+ if (err < 0) {
+ fprintf(stderr, "prctl failed to device index: %d\n", errno);
+ return -1;
+ }
+
+ return 0;
+}
+
+/* get vrf context for given process id */
+static int get_vrf(pid_t pid)
+{
+ int vrf;
+ long err;
+
+ /* lookup device index pid is tied to */
+ err = prctl(PR_GET_SK_BIND_DEV_IF, pid);
+ if (err < 0) {
+ fprintf(stderr, "prctl failed: %d\n", errno);
+ return -1;
+ }
+
+ if (err == 0)
+ return 0;
+
+ /* convert device index to vrf id */
+ vrf = device_to_vrf((int)err);
+ if (vrf < 0) {
+ fprintf(stderr, "Failed to get device index for vrf %d\n", vrf);
+ return -1;
+ }
+
+ return vrf;
+}
+
+static int run_vrf(char **argv, int vrf)
+{
+ char *cmd;
+
+ if (set_vrf(vrf) != 0) {
+ fprintf(stderr, "Failed to set vrf context\n");
+ return 1;
+ }
+
+ cmd = strdup(argv[0]);
+ if (!cmd) {
+ fprintf(stderr, "Failed to set command\n");
+ return 1;
+ }
+ argv[0] = basename(argv[0]);
+ if (execvp(cmd, argv) < 0)
+ perror("Failed to exec command\n");
+
+ return 1;
+}
+
+static int show_vrf(pid_t pid)
+{
+ int vrf = get_vrf(pid);
+
+ switch (vrf) {
+ case -1:
+ fprintf(stderr, "Failed to get vrf context for pid %d\n", pid);
+ if (kill(pid, 0) < 0) {
+ if (errno == ESRCH)
+ fprintf(stderr, "No process with given pid\n");
+ }
+ break;
+ case 0:
+ printf("Process %d is not running in a VRF context\n", pid);
+ break;
+ default:
+ printf("Process %d is running in VRF %d\n", pid, vrf);
+ }
+ return vrf < 0 ? 1 : 0;
+}
+
+static void usage(char *_prog)
+{
+ const char *prog = basename(_prog);
+
+ fprintf(stderr, "usage:\n");
+ fprintf(stderr, "\nShow VRF context for given pid\n");
+ fprintf(stderr, "\t%s -p pid\n", prog);
+ fprintf(stderr, "\nRun command in given VRF context\n");
+ fprintf(stderr, "\t%s -v vrf <command>\n", prog);
+}
+
+int main(int argc, char *argv[])
+{
+ int rc;
+ pid_t pid = 0;
+ int vrf = 0;
+
+ extern char *optarg;
+ extern int optind;
+
+ while ((rc = getopt(argc, argv, "+:p:v:")) != -1) {
+ switch (rc) {
+ case 'p':
+ pid = atoi(optarg);
+ break;
+ case 'v':
+ vrf = atoi(optarg);
+ break;
+ default:
+ usage(argv[0]);
+ return 1;
+ }
+ }
+
+ if ((pid && vrf) || (!pid && !vrf)) {
+ usage(argv[0]);
+ return 1;
+ }
+
+ if (pid)
+ return show_vrf(pid);
+
+ if (optind == argc) {
+ usage(argv[0]);
+ return 1;
+ }
+
+ return run_vrf(&argv[optind], vrf);
+}
--
2.3.2 (Apple Git-55)
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