Author: cem
Date: Mon Sep  9 22:54:27 2019
New Revision: 352112
URL: https://svnweb.freebsd.org/changeset/base/352112

Log:
  ddb(4): Add 'show route <dest>' and 'show routetable [<af>]'
  
  These commands show the route resolved for a specified destination, or
  print out the entire routing table for a given address family (or all
  families, if none is explicitly provided).
  
  Discussed with:       emaste
  Differential Revision:        https://reviews.freebsd.org/D21510

Modified:
  head/share/man/man4/ddb.4
  head/sys/net/rtsock.c

Modified: head/share/man/man4/ddb.4
==============================================================================
--- head/share/man/man4/ddb.4   Mon Sep  9 22:08:22 2019        (r352111)
+++ head/share/man/man4/ddb.4   Mon Sep  9 22:54:27 2019        (r352112)
@@ -60,7 +60,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd November 30, 2018
+.Dd September 9, 2019
 .Dt DDB 4
 .Os
 .Sh NAME
@@ -953,6 +953,20 @@ at address
 .Ar addr .
 Addresses of particular pointers can be gathered with "show allrman"
 command.
+.\"
+.Pp
+.It Ic show Cm route Ar addr
+Show route table result for destination
+.Ar addr .
+At this time, INET and INET6 formatted addresses are supported.
+.\"
+.Pp
+.It Ic show Cm routetable Oo Ar af Oc
+Show full route table or tables.
+If
+.Ar af
+is specified, show only routes for the given numeric address family.
+If no argument is specified, dump the route table for all address families.
 .\"
 .Pp
 .It Ic show Cm rtc

Modified: head/sys/net/rtsock.c
==============================================================================
--- head/sys/net/rtsock.c       Mon Sep  9 22:08:22 2019        (r352111)
+++ head/sys/net/rtsock.c       Mon Sep  9 22:54:27 2019        (r352112)
@@ -31,6 +31,7 @@
  *     @(#)rtsock.c    8.7 (Berkeley) 10/12/95
  * $FreeBSD$
  */
+#include "opt_ddb.h"
 #include "opt_mpath.h"
 #include "opt_inet.h"
 #include "opt_inet6.h"
@@ -53,6 +54,11 @@
 #include <sys/sysctl.h>
 #include <sys/systm.h>
 
+#ifdef DDB
+#include <ddb/ddb.h>
+#include <ddb/db_lex.h>
+#endif
+
 #include <net/if.h>
 #include <net/if_var.h>
 #include <net/if_dl.h>
@@ -1995,3 +2001,404 @@ static struct domain routedomain = {
 };
 
 VNET_DOMAIN_SET(route);
+
+#ifdef DDB
+/*
+ * Unfortunately, RTF_ values are expressed as raw masks rather than powers of
+ * 2, so we cannot use them as nice C99 initializer indices below.
+ */
+static const char * const rtf_flag_strings[] = {
+       "UP",
+       "GATEWAY",
+       "HOST",
+       "REJECT",
+       "DYNAMIC",
+       "MODIFIED",
+       "DONE",
+       "UNUSED_0x80",
+       "UNUSED_0x100",
+       "XRESOLVE",
+       "LLDATA",
+       "STATIC",
+       "BLACKHOLE",
+       "UNUSED_0x2000",
+       "PROTO2",
+       "PROTO1",
+       "UNUSED_0x10000",
+       "UNUSED_0x20000",
+       "PROTO3",
+       "FIXEDMTU",
+       "PINNED",
+       "LOCAL",
+       "BROADCAST",
+       "MULTICAST",
+       /* Big gap. */
+       [28] = "STICKY",
+       [30] = "RNH_LOCKED",
+       [31] = "GWFLAG_COMPAT",
+};
+
+static const char * __pure
+rt_flag_name(unsigned idx)
+{
+       if (idx >= nitems(rtf_flag_strings))
+               return ("INVALID_FLAG");
+       if (rtf_flag_strings[idx] == NULL)
+               return ("UNKNOWN");
+       return (rtf_flag_strings[idx]);
+}
+
+static void
+rt_dumpaddr_ddb(const char *name, const struct sockaddr *sa)
+{
+       char buf[INET6_ADDRSTRLEN], *res;
+
+       res = NULL;
+       if (sa == NULL)
+               res = "NULL";
+       else if (sa->sa_family == AF_INET) {
+               res = inet_ntop(AF_INET,
+                   &((const struct sockaddr_in *)sa)->sin_addr,
+                   buf, sizeof(buf));
+       } else if (sa->sa_family == AF_INET6) {
+               res = inet_ntop(AF_INET6,
+                   &((const struct sockaddr_in6 *)sa)->sin6_addr,
+                   buf, sizeof(buf));
+       } else if (sa->sa_family == AF_LINK) {
+               res = "on link";
+       }
+
+       if (res != NULL) {
+               db_printf("%s <%s> ", name, res);
+               return;
+       }
+
+       db_printf("%s <af:%d> ", name, sa->sa_family);
+}
+
+static int
+rt_dumpentry_ddb(struct radix_node *rn, void *arg __unused)
+{
+       struct sockaddr_storage ss;
+       struct rtentry *rt;
+       int flags, idx;
+
+       /* If RNTORT is important, put it in a header. */
+       rt = (void *)rn;
+
+       rt_dumpaddr_ddb("dst", rt_key(rt));
+       rt_dumpaddr_ddb("gateway", rt->rt_gateway);
+       rt_dumpaddr_ddb("netmask", rtsock_fix_netmask(rt_key(rt), rt_mask(rt),
+           &ss));
+       if (rt->rt_ifp != NULL && (rt->rt_ifp->if_flags & IFF_DYING) == 0) {
+               rt_dumpaddr_ddb("ifp", rt->rt_ifp->if_addr->ifa_addr);
+               rt_dumpaddr_ddb("ifa", rt->rt_ifa->ifa_addr);
+       }
+
+       db_printf("flags ");
+       flags = rt->rt_flags;
+       if (flags == 0)
+               db_printf("none");
+
+       while ((idx = ffs(flags)) > 0) {
+               idx--;
+
+               if (flags != rt->rt_flags)
+                       db_printf(",");
+               db_printf(rt_flag_name(idx));
+
+               flags &= ~(1ul << idx);
+       }
+
+       db_printf("\n");
+       return (0);
+}
+
+DB_SHOW_COMMAND(routetable, db_show_routetable_cmd)
+{
+       struct rib_head *rnh;
+       int error, i, lim;
+
+       if (have_addr)
+               i = lim = addr;
+       else {
+               i = 1;
+               lim = AF_MAX;
+       }
+
+       for (; i <= lim; i++) {
+               rnh = rt_tables_get_rnh(0, i);
+               if (rnh == NULL) {
+                       if (have_addr) {
+                               db_printf("%s: AF %d not supported?\n",
+                                   __func__, i);
+                               break;
+                       }
+                       continue;
+               }
+
+               if (!have_addr && i > 1)
+                       db_printf("\n");
+
+               db_printf("Route table for AF %d%s%s%s:\n", i,
+                   (i == AF_INET || i == AF_INET6) ? " (" : "",
+                   (i == AF_INET) ? "INET" : (i == AF_INET6) ? "INET6" : "",
+                   (i == AF_INET || i == AF_INET6) ? ")" : "");
+
+               error = rnh->rnh_walktree(&rnh->head, rt_dumpentry_ddb, NULL);
+               if (error != 0)
+                       db_printf("%s: walktree(%d): %d\n", __func__, i,
+                           error);
+       }
+}
+
+_DB_FUNC(_show, route, db_show_route_cmd, db_show_table, CS_OWN, NULL)
+{
+       char buf[INET6_ADDRSTRLEN], *bp;
+       const void *dst_addrp;
+       struct sockaddr *dstp;
+       struct rtentry *rt;
+       union {
+               struct sockaddr_in dest_sin;
+               struct sockaddr_in6 dest_sin6;
+       } u;
+       uint16_t hextets[8];
+       unsigned i, tets;
+       int t, af, exp, tokflags;
+
+       /*
+        * Undecoded address family.  No double-colon expansion seen yet.
+        */
+       af = -1;
+       exp = -1;
+       /* Assume INET6 to start; we can work back if guess was wrong. */
+       tokflags = DRT_WSPACE | DRT_HEX | DRT_HEXADECIMAL;
+
+       /*
+        * db_command has lexed 'show route' for us.
+        */
+       t = db_read_token_flags(tokflags);
+       if (t == tWSPACE)
+               t = db_read_token_flags(tokflags);
+
+       /*
+        * tEOL: Just 'show route' isn't a valid mode.
+        * tMINUS: It's either '-h' or some invalid option.  Regardless, usage.
+        */
+       if (t == tEOL || t == tMINUS)
+               goto usage;
+
+       db_unread_token(t);
+
+       tets = nitems(hextets);
+
+       /*
+        * Each loop iteration, we expect to read one octet (v4) or hextet
+        * (v6), followed by an appropriate field separator ('.' or ':' or
+        * '::').
+        *
+        * At the start of each loop, we're looking for a number (octet or
+        * hextet).
+        *
+        * INET6 addresses have a special case where they may begin with '::'.
+        */
+       for (i = 0; i < tets; i++) {
+               t = db_read_token_flags(tokflags);
+
+               if (t == tCOLONCOLON) {
+                       /* INET6 with leading '::' or invalid. */
+                       if (i != 0) {
+                               db_printf("Parse error: unexpected extra "
+                                   "colons.\n");
+                               goto exit;
+                       }
+
+                       af = AF_INET6;
+                       exp = i;
+                       hextets[i] = 0;
+                       continue;
+               } else if (t == tNUMBER) {
+                       /*
+                        * Lexer separates out '-' as tMINUS, but make the
+                        * assumption explicit here.
+                        */
+                       MPASS(db_tok_number >= 0);
+
+                       if (af == AF_INET && db_tok_number > UINT8_MAX) {
+                               db_printf("Not a valid v4 octet: %ld\n",
+                                   db_tok_number);
+                               goto exit;
+                       }
+                       hextets[i] = db_tok_number;
+               } else if (t == tEOL) {
+                       /*
+                        * We can only detect the end of an IPv6 address in
+                        * compact representation with EOL.
+                        */
+                       if (af != AF_INET6 || exp < 0) {
+                               db_printf("Parse failed.  Got unexpected EOF "
+                                   "when the address is not a compact-"
+                                   "representation IPv6 address.\n");
+                               goto exit;
+                       }
+                       break;
+               } else {
+                       db_printf("Parse failed.  Unexpected token %d.\n", t);
+                       goto exit;
+               }
+
+               /* Next, look for a separator, if appropriate. */
+               if (i == tets - 1)
+                       continue;
+
+               t = db_read_token_flags(tokflags);
+               if (af < 0) {
+                       if (t == tCOLON) {
+                               af = AF_INET6;
+                               continue;
+                       }
+                       if (t == tCOLONCOLON) {
+                               af = AF_INET6;
+                               i++;
+                               hextets[i] = 0;
+                               exp = i;
+                               continue;
+                       }
+                       if (t == tDOT) {
+                               unsigned hn, dn;
+
+                               af = AF_INET;
+                               /* Need to fixup the first parsed number. */
+                               if (hextets[0] > 0x255 ||
+                                   (hextets[0] & 0xf0) > 0x90 ||
+                                   (hextets[0] & 0xf) > 9) {
+                                       db_printf("Not a valid v4 octet: %x\n",
+                                           hextets[0]);
+                                       goto exit;
+                               }
+
+                               hn = hextets[0];
+                               dn = (hn >> 8) * 100 +
+                                   ((hn >> 4) & 0xf) * 10 +
+                                   (hn & 0xf);
+
+                               hextets[0] = dn;
+
+                               /* Switch to decimal for remaining octets. */
+                               tokflags &= ~DRT_RADIX_MASK;
+                               tokflags |= DRT_DECIMAL;
+
+                               tets = 4;
+                               continue;
+                       }
+
+                       db_printf("Parse error.  Unexpected token %d.\n", t);
+                       goto exit;
+               } else if (af == AF_INET) {
+                       if (t == tDOT)
+                               continue;
+                       db_printf("Expected '.' (%d) between octets but got "
+                           "(%d).\n", tDOT, t);
+                       goto exit;
+
+               } else if (af == AF_INET6) {
+                       if (t == tCOLON)
+                               continue;
+                       if (t == tCOLONCOLON) {
+                               if (exp < 0) {
+                                       i++;
+                                       hextets[i] = 0;
+                                       exp = i;
+                                       continue;
+                               }
+                               db_printf("Got bogus second '::' in v6 "
+                                   "address.\n");
+                               goto exit;
+                       }
+                       if (t == tEOL) {
+                               /*
+                                * Handle in the earlier part of the loop
+                                * because we need to handle trailing :: too.
+                                */
+                               db_unread_token(t);
+                               continue;
+                       }
+
+                       db_printf("Expected ':' (%d) or '::' (%d) between "
+                           "hextets but got (%d).\n", tCOLON, tCOLONCOLON, t);
+                       goto exit;
+               }
+       }
+
+       /* Check for trailing garbage. */
+       if (i == tets) {
+               t = db_read_token_flags(tokflags);
+               if (t != tEOL) {
+                       db_printf("Got unexpected garbage after address "
+                           "(%d).\n", t);
+                       goto exit;
+               }
+       }
+
+       /*
+        * Need to expand compact INET6 addresses.
+        *
+        * Technically '::' for a single ':0:' is MUST NOT but just in case,
+        * don't bother expanding that form (exp >= 0 && i == tets case).
+        */
+       if (af == AF_INET6 && exp >= 0 && i < tets) {
+               if (exp + 1 < i) {
+                       memmove(&hextets[exp + 1 + (nitems(hextets) - i)],
+                           &hextets[exp + 1],
+                           (i - (exp + 1)) * sizeof(hextets[0]));
+               }
+               memset(&hextets[exp + 1], 0, (nitems(hextets) - i) *
+                   sizeof(hextets[0]));
+       }
+
+       memset(&u, 0, sizeof(u));
+       if (af == AF_INET) {
+               u.dest_sin.sin_family = AF_INET;
+               u.dest_sin.sin_len = sizeof(u.dest_sin);
+               u.dest_sin.sin_addr.s_addr = htonl(
+                   ((uint32_t)hextets[0] << 24) |
+                   ((uint32_t)hextets[1] << 16) |
+                   ((uint32_t)hextets[2] << 8) |
+                   (uint32_t)hextets[3]);
+               dstp = (void *)&u.dest_sin;
+               dst_addrp = &u.dest_sin.sin_addr;
+       } else if (af == AF_INET6) {
+               u.dest_sin6.sin6_family = AF_INET6;
+               u.dest_sin6.sin6_len = sizeof(u.dest_sin6);
+               for (i = 0; i < nitems(hextets); i++)
+                       u.dest_sin6.sin6_addr.s6_addr16[i] = htons(hextets[i]);
+               dstp = (void *)&u.dest_sin6;
+               dst_addrp = &u.dest_sin6.sin6_addr;
+       } else
+               MPASS(false);
+
+       bp = inet_ntop(af, dst_addrp, buf, sizeof(buf));
+       if (bp != NULL)
+               db_printf("Looking up route to destination '%s'\n", bp);
+
+       CURVNET_SET(vnet0);
+       rt = rtalloc1(dstp, 0, RTF_RNH_LOCKED);
+       CURVNET_RESTORE();
+
+       if (rt == NULL) {
+               db_printf("Could not get route for that server.\n");
+               return;
+       }
+
+       rt_dumpentry_ddb((void *)rt, NULL);
+       RTFREE_LOCKED(rt);
+
+       return;
+usage:
+       db_printf("Usage: 'show route <address>'\n"
+           "  Currently accepts only dotted-decimal INET or colon-separated\n"
+           "  hextet INET6 addresses.\n");
+exit:
+       db_skip_to_eol();
+}
+#endif
_______________________________________________
svn-src-all@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"

Reply via email to