From 3fdbb1f797ee9fe9260af92f5d7ea760684cd271 Mon Sep 17 00:00:00 2001 From: Steven Barth Date: Tue, 18 Feb 2014 13:18:32 +0100 Subject: [PATCH] Allow routes with source ::/128 for SAS on Linux Linux uses the source-address :: (unspecified) to lookup routes in the routing table for connections that are not bound to a specific source address (e.g. ping6 2001:db8::1). If all default routes are source-restricted a command like above will result in a "Permission denied" error and no packets are being sent. Adding a default route with source ::/128 avoids this issue. This patch excludes ::/128 from the "martian_prefix" check for source prefixes and thus allows such auxiliary routes to be distributed. Signed-off-by: Steven Barth --- kernel_netlink.c | 4 ++-- route.c | 4 ++-- util.c | 4 ++-- util.h | 2 +- xroute.c | 2 +- 5 files changed, 8 insertions(+), 8 deletions(-) diff --git a/kernel_netlink.c b/kernel_netlink.c index 8b9099c..2e174af 100644 --- a/kernel_netlink.c +++ b/kernel_netlink.c @@ -1236,8 +1236,8 @@ filter_kernel_routes(struct nlmsghdr *nh, void *data) if(rc < 0) return 0; - if(martian_prefix(current_route->prefix, current_route->plen) || - martian_prefix(current_route->src_prefix, current_route->src_plen)) + if(martian_prefix(current_route->prefix, current_route->plen, 0) || + martian_prefix(current_route->src_prefix, current_route->src_plen, 1)) return 0; /* Ignore default unreachable routes; no idea where they come from. */ diff --git a/route.c b/route.c index a97e8ed..c709303 100644 --- a/route.c +++ b/route.c @@ -1371,12 +1371,12 @@ update_route(const unsigned char *id, if(memcmp(id, myid, 8) == 0) return NULL; - if(martian_prefix(prefix, plen)) { + if(martian_prefix(prefix, plen, 0)) { fprintf(stderr, "Rejecting martian route to %s through %s.\n", format_prefix(prefix, plen), format_address(id)); return NULL; } - if(src_plen != 0 && martian_prefix(src_prefix, src_plen)) { + if(src_plen != 0 && martian_prefix(src_prefix, src_plen, 1)) { fprintf(stderr, "Rejecting martian route to %s from %s through %s.\n", format_prefix(prefix, plen), format_prefix(src_prefix, src_plen), format_address(id)); diff --git a/util.c b/util.c index cdb4ab2..80930e4 100644 --- a/util.c +++ b/util.c @@ -425,13 +425,13 @@ wait_for_fd(int direction, int fd, int msecs) } int -martian_prefix(const unsigned char *prefix, int plen) +martian_prefix(const unsigned char *prefix, int plen, int is_source) { return (plen >= 8 && prefix[0] == 0xFF) || (plen >= 10 && prefix[0] == 0xFE && (prefix[1] & 0xC0) == 0x80) || (plen >= 128 && memcmp(prefix, zeroes, 15) == 0 && - (prefix[15] == 0 || prefix[15] == 1)) || + ((prefix[15] == 0 && !is_source) || prefix[15] == 1)) || (plen >= 96 && v4mapped(prefix) && ((plen >= 104 && (prefix[12] == 127 || prefix[12] == 0)) || (plen >= 100 && (prefix[12] & 0xE0) == 0xE0))); diff --git a/util.h b/util.h index 935481f..f399b8a 100644 --- a/util.h +++ b/util.h @@ -95,7 +95,7 @@ int parse_net(const char *net, unsigned char *prefix_r, unsigned char *plen_r, int *af_r); int parse_eui64(const char *eui, unsigned char *eui_r); int wait_for_fd(int direction, int fd, int msecs); -int martian_prefix(const unsigned char *prefix, int plen) ATTRIBUTE ((pure)); +int martian_prefix(const unsigned char *prefix, int plen, int is_source) ATTRIBUTE ((pure)); int linklocal(const unsigned char *address) ATTRIBUTE ((pure)); int v4mapped(const unsigned char *address) ATTRIBUTE ((pure)); void v4tov6(unsigned char *dst, const unsigned char *src); diff --git a/xroute.c b/xroute.c index e8b3b11..e4bd12a 100644 --- a/xroute.c +++ b/xroute.c @@ -259,7 +259,7 @@ check_xroutes(int send_updates) /* Add any new routes */ for(i = 0; i < numroutes; i++) { - if(martian_prefix(routes[i].prefix, routes[i].plen)) + if(martian_prefix(routes[i].prefix, routes[i].plen, 0)) continue; metric = redistribute_filter(routes[i].prefix, routes[i].plen, routes[i].src_prefix, routes[i].src_plen, -- 1.8.5.3