zebra: increase maximum label stack depth

* Bump MPLS_MAX_LABELS from 2 to 16;
* Adjust the static_nh_label structure and the mpls_label2str() function;
* On OpenBSD, print an error message when trying to push more than one
  label at once (kernel limitation). While here, add support for MPLSv6
  FTNs in OpenBSD.

This is not the full package. We still can't pop multiple labels at once,
or do things like swap a label and push other ones. We'll address that
in the future.

Signed-off-by: Renato Westphal <renato@opensourcerouting.org>

diff --git a/zebra/rt_socket.c b/zebra/rt_socket.c
index 4e4d726b4618042ad7878bc0f073a7d40582bc39..32ae41b917cd77496efd9a4e7cc63561bba311b5 100644 (file)
--- a/zebra/rt_socket.c
+++ b/zebra/rt_socket.c
@@ -71,6 +71,27 @@ static int sin_masklen(struct in_addr mask)
 }
 #endif /* HAVE_STRUCT_SOCKADDR_IN_SIN_LEN */
 
+#ifdef __OpenBSD__
+static int kernel_rtm_add_labels(struct nexthop_label *nh_label,
+                                struct sockaddr_mpls *smpls)
+{
+       if (nh_label->num_labels > 1) {
+               zlog_warn(
+                       "%s: can't push %u labels at "
+                       "once (maximum is 1)",
+                       __func__, nh_label->num_labels);
+               return -1;
+       }
+
+       memset(smpls, 0, sizeof(*smpls));
+       smpls->smpls_len = sizeof(*smpls);
+       smpls->smpls_family = AF_MPLS;
+       smpls->smpls_label = htonl(nh_label->label[0] << MPLS_LABEL_OFFSET);
+
+       return 0;
+}
+#endif
+
 /* Interface between zebra message and rtm message. */
 static int kernel_rtm_ipv4(int cmd, struct prefix *p, struct route_entry *re)
 
@@ -150,15 +171,11 @@ static int kernel_rtm_ipv4(int cmd, struct prefix *p, struct route_entry *re)
                        }
 
 #ifdef __OpenBSD__
-                       if (nexthop->nh_label) {
-                               memset(&smpls, 0, sizeof(smpls));
-                               smpls.smpls_len = sizeof(smpls);
-                               smpls.smpls_family = AF_MPLS;
-                               smpls.smpls_label =
-                                       htonl(nexthop->nh_label->label[0]
-                                             << MPLS_LABEL_OFFSET);
-                               smplsp = (union sockunion *)&smpls;
-                       }
+                       if (nexthop->nh_label
+                           && !kernel_rtm_add_labels(nexthop->nh_label,
+                                                     &smpls))
+                               continue;
+                       smplsp = (union sockunion *)&smpls;
 #endif
 
                        error = rtm_write(
@@ -266,6 +283,10 @@ static int kernel_rtm_ipv6(int cmd, struct prefix *p, struct route_entry *re)
 {
        struct sockaddr_in6 *mask;
        struct sockaddr_in6 sin_dest, sin_mask, sin_gate;
+#ifdef __OpenBSD__
+       struct sockaddr_mpls smpls;
+#endif
+       union sockunion *smplsp = NULL;
        struct nexthop *nexthop;
        int nexthop_num = 0;
        ifindex_t ifindex = 0;
@@ -338,10 +359,17 @@ static int kernel_rtm_ipv6(int cmd, struct prefix *p, struct route_entry *re)
                        mask = &sin_mask;
                }
 
+#ifdef __OpenBSD__
+               if (nexthop->nh_label
+                   && !kernel_rtm_add_labels(nexthop->nh_label, &smpls))
+                       continue;
+               smplsp = (union sockunion *)&smpls;
+#endif
+
                error = rtm_write(cmd, (union sockunion *)&sin_dest,
                                  (union sockunion *)mask,
                                  gate ? (union sockunion *)&sin_gate : NULL,
-                                 NULL, ifindex, re->flags, re->metric);
+                                 smplsp, ifindex, re->flags, re->metric);
 
 #if 0
       if (error)

diff --git a/zebra/zebra_mpls.c b/zebra/zebra_mpls.c
index 47cf7a3cbfc056ddda0276125f18b136c4dec7c2..cee3a03858b1d6e8f34c7e73f9a05866f558308e 100644 (file)
--- a/zebra/zebra_mpls.c
+++ b/zebra/zebra_mpls.c
@@ -1671,27 +1671,20 @@ int mpls_str2label(const char *label_str, u_int8_t *num_labels,
 char *mpls_label2str(u_int8_t num_labels, mpls_label_t *labels, char *buf,
                     int len, int pretty)
 {
-       char *buf_ptr = buf;
-       buf[0] = '\0';
-
-       if (pretty) {
-               if (num_labels == 1) {
-                       label2str(labels[0], buf, len);
-               } else if (num_labels == 2) {
-                       label2str(labels[0], buf, len);
-                       buf_ptr += strlen(buf);
+       char label_buf[BUFSIZ];
+       int i;
 
-                       snprintf(buf_ptr, len, "/");
-                       buf_ptr++;
-
-                       label2str(labels[1], buf_ptr, len);
-               }
-       } else {
-               if (num_labels == 1)
-                       snprintf(buf, len, "%u", labels[0]);
-               else if (num_labels == 2)
-                       snprintf(buf, len, "%u/%u", labels[0], labels[1]);
+       buf[0] = '\0';
+       for (i = 0; i < num_labels; i++) {
+               if (i != 0)
+                       strlcat(buf, "/", len);
+               if (pretty)
+                       label2str(labels[i], label_buf, sizeof(label_buf));
+               else
+                       snprintf(label_buf, sizeof(label_buf), "%u", labels[i]);
+               strlcat(buf, label_buf, len);
        }
+
        return buf;
 }
 

diff --git a/zebra/zebra_mpls.h b/zebra/zebra_mpls.h
index c8dab39210ea97cc918a26720d7182f3c3170f6d..6bddc4d00f15178622032b58545e097235ff8a88 100644 (file)
--- a/zebra/zebra_mpls.h
+++ b/zebra/zebra_mpls.h
@@ -37,7 +37,7 @@
 
 /* Definitions and macros. */
 
-#define MPLS_MAX_LABELS 2  /* Maximum # labels that can be pushed. */
+#define MPLS_MAX_LABELS 16  /* Maximum # labels that can be pushed. */
 
 #define NHLFE_FAMILY(nhlfe)                                                    \
        (((nhlfe)->nexthop->type == NEXTHOP_TYPE_IPV6                          \

diff --git a/zebra/zebra_mpls_openbsd.c b/zebra/zebra_mpls_openbsd.c
index 119cd5b700c2aa62bebc1675cc81fa6eeda1c0ae..33f0d49d4d5babd9a299f318675295b7158a1e8d 100644 (file)
--- a/zebra/zebra_mpls_openbsd.c
+++ b/zebra/zebra_mpls_openbsd.c
@@ -256,6 +256,15 @@ static int kernel_lsp_cmd(int action, zebra_lsp_t *lsp)
                    || (action == RTM_DELETE
                        && (CHECK_FLAG(nhlfe->flags, NHLFE_FLAG_INSTALLED)
                            && CHECK_FLAG(nexthop->flags, NEXTHOP_FLAG_FIB)))) {
+                       if (nhlfe->nexthop->nh_label->num_labels > 1) {
+                               zlog_warn(
+                                       "%s: can't push %u labels at once "
+                                       "(maximum is 1)",
+                                       __func__,
+                                       nhlfe->nexthop->nh_label->num_labels);
+                               continue;
+                       }
+
                        nexthop_num++;
 
                        switch (NHLFE_FAMILY(nhlfe)) {

diff --git a/zebra/zebra_static.h b/zebra/zebra_static.h
index 6ab47094a1498d545c2a7a3319d881a9ae043a68..ff9f0f59e7da5d55ab90584a6a73f34ae77d607b 100644 (file)
--- a/zebra/zebra_static.h
+++ b/zebra/zebra_static.h
@@ -22,11 +22,13 @@
 #ifndef __ZEBRA_STATIC_H__
 #define __ZEBRA_STATIC_H__
 
+#include "zebra/zebra_mpls.h"
+
 /* Static route label information */
 struct static_nh_label {
        u_int8_t num_labels;
        u_int8_t reserved[3];
-       mpls_label_t label[2];
+       mpls_label_t label[MPLS_MAX_LABELS];
 };
 
 typedef enum {