If it interests anyone, I've also implemented the route option described in https://tools.ietf.org/html/rfc4191#section-2.3
I find sharing patches via this mailing list particularly unwieldy, so I've pushed my work to a git branch at https://github.com/cqcallaw/src/tree/rfc-4191 On Wed, Aug 7, 2019 at 11:27 PM Caleb <[email protected]> wrote: > > Thank you for the code and review! I've synthesized the existing patch > and review into something that successfully advertises router > preferences in local testing (verified w/ rdisc6). This patch does not > implement the route information option specified in RFC 4191 section > 2.3. > > diff --git a/usr.sbin/rad/frontend.c b/usr.sbin/rad/frontend.c > index 8178b058629..4031da6b99d 100644 > --- a/usr.sbin/rad/frontend.c > +++ b/usr.sbin/rad/frontend.c > @@ -411,7 +411,7 @@ frontend_dispatch_main(int fd, short event, void *bula) > ra_prefix_conf)) > fatalx("%s: IMSG_RECONF_RA_PREFIX wrong " > "length: %lu", __func__, > - IMSG_DATA_SIZE(imsg)); > + IMSG_DATA_SIZE(imsg)); > if ((ra_prefix_conf = malloc(sizeof(struct > ra_prefix_conf))) == NULL) > fatal(NULL); > @@ -1023,6 +1023,18 @@ build_packet(struct ra_iface *ra_iface) > ra->nd_ra_router_lifetime = > htons(ra_options_conf->router_lifetime); > } > + > + /* add router preference flags */ > + if (ra_options_conf->preference == ND_RA_FLAG_RTPREF_RSV) { > + fatalx("Invalid router preference found during RA packet > construction."); > + } > + > + if (ra_options_conf->router_lifetime == 0) { > + log_debug("Router lifetime set to zero; ignoring router > preference per https://tools.ietf.org/html/rfc4191#section-2.2";); > + } else { > + ra->nd_ra_flags_reserved |= ra_options_conf->preference; > + } > + > ra->nd_ra_reachable = htonl(ra_options_conf->reachable_time); > ra->nd_ra_retransmit = htonl(ra_options_conf->retrans_timer); > p += sizeof(*ra); > diff --git a/usr.sbin/rad/parse.y b/usr.sbin/rad/parse.y > index 004e5e22f92..74480148246 100644 > --- a/usr.sbin/rad/parse.y > +++ b/usr.sbin/rad/parse.y > @@ -32,6 +32,7 @@ > #include <net/if.h> > #include <arpa/inet.h> > +#include <netinet/icmp6.h> > #include <ctype.h> > #include <err.h> > @@ -117,10 +118,12 @@ typedef struct { > %token CONFIGURATION OTHER LIFETIME REACHABLE TIME RETRANS TIMER > %token AUTO PREFIX VALID PREFERRED LIFETIME ONLINK AUTONOMOUS > %token ADDRESS_CONFIGURATION DNS NAMESERVER SEARCH MTU > +%token PREFERENCE LOW MEDIUM HIGH > %token <v.string> STRING > %token <v.number> NUMBER > %type <v.number> yesno > +%type <v.number> preference > %type <v.string> string > %% > @@ -166,6 +169,11 @@ yesno : YES { $$ = 1; } > | NO { $$ = 0; } > ; > +preference : LOW { $$ = ND_RA_FLAG_RTPREF_LOW; } > + | MEDIUM { $$ = ND_RA_FLAG_RTPREF_MEDIUM; } > + | HIGH { $$ = ND_RA_FLAG_RTPREF_HIGH; } > + ; > + > varset : STRING '=' string { > char *s = $1; > if (cmd_opts & OPT_VERBOSE) > @@ -213,6 +221,9 @@ ra_opt_block : DEFAULT ROUTER yesno { > | MTU NUMBER { > ra_options->mtu = $2; > } > + | PREFERENCE preference { > + ra_options->preference = $2; > + } > | DNS dns_block > ; > @@ -426,16 +437,20 @@ lookup(char *s) > {"default", DEFAULT}, > {"dns", DNS}, > {"hop", HOP}, > + {"high", HIGH}, > {"include", INCLUDE}, > {"interface", RA_IFACE}, > {"lifetime", LIFETIME}, > {"limit", LIMIT}, > + {"low", LOW}, > {"managed", MANAGED}, > + {"medium", MEDIUM}, > {"mtu", MTU}, > {"nameserver", NAMESERVER}, > {"no", NO}, > {"on-link", ONLINK}, > {"other", OTHER}, > + {"preference", PREFERENCE}, > {"preferred", PREFERRED}, > {"prefix", PREFIX}, > {"reachable", REACHABLE}, > diff --git a/usr.sbin/rad/printconf.c b/usr.sbin/rad/printconf.c > index d42890da518..c2173d2142f 100644 > --- a/usr.sbin/rad/printconf.c > +++ b/usr.sbin/rad/printconf.c > @@ -26,6 +26,7 @@ > #include <net/if.h> > #include <arpa/inet.h> > +#include <netinet/icmp6.h> > #include <event.h> > #include <imsg.h> > @@ -34,6 +35,7 @@ > #include "rad.h" > const char* yesno(int); > +const char* preference(int); > void print_ra_options(const char*, const struct ra_options_conf*); > void print_prefix_options(const char*, const struct ra_prefix_conf*); > @@ -42,6 +44,20 @@ yesno(int flag) > { > return flag ? "yes" : "no"; > } > +const char* > +preference(int p) > +{ > + switch (p) { > + case ND_RA_FLAG_RTPREF_LOW: > + return "low"; > + case ND_RA_FLAG_RTPREF_MEDIUM: > + return "medium"; > + case ND_RA_FLAG_RTPREF_HIGH: > + return "high"; > + default: > + return "invalid"; > + } > +} > void > print_ra_options(const char *indent, const struct ra_options_conf *ra_options) > @@ -60,6 +76,9 @@ print_ra_options(const char *indent, const struct > ra_options_conf *ra_options) > printf("%sretrans timer %u\n", indent, ra_options->retrans_timer); > if (ra_options->mtu > 0) > printf("%smtu %u\n", indent, ra_options->mtu); > + if (ra_options->preference != ND_RA_FLAG_RTPREF_RSV) > + printf("%spreference %s\n", indent, > + preference(ra_options->preference)); > if (!SIMPLEQ_EMPTY(&ra_options->ra_rdnss_list) || > !SIMPLEQ_EMPTY(&ra_options->ra_dnssl_list)) { > diff --git a/usr.sbin/rad/rad.c b/usr.sbin/rad/rad.c > index 93675167b6b..cb0593f11ab 100644 > --- a/usr.sbin/rad/rad.c > +++ b/usr.sbin/rad/rad.c > @@ -433,7 +433,7 @@ main_dispatch_frontend(int fd, short event, void *bula) > case IMSG_CTL_LOG_VERBOSE: > if (IMSG_DATA_SIZE(imsg) != sizeof(verbose)) > fatalx("%s: IMSG_CTL_LOG_VERBOSE wrong length: " > - "%lu", __func__, IMSG_DATA_SIZE(imsg)); > + "%lu", __func__, IMSG_DATA_SIZE(imsg)); > memcpy(&verbose, imsg.data, sizeof(verbose)); > log_setverbose(verbose); > break; > @@ -754,6 +754,7 @@ config_new_empty(void) > xconf->ra_options.cur_hl = 0; > xconf->ra_options.m_flag = 0; > xconf->ra_options.o_flag = 0; > + xconf->ra_options.preference = ND_RA_FLAG_RTPREF_MEDIUM; > xconf->ra_options.router_lifetime = 1800; > xconf->ra_options.reachable_time = 0; > xconf->ra_options.retrans_timer = 0; > diff --git a/usr.sbin/rad/rad.conf.5 b/usr.sbin/rad/rad.conf.5 > index f651a715d1a..b822f3d195d 100644 > --- a/usr.sbin/rad/rad.conf.5 > +++ b/usr.sbin/rad/rad.conf.5 > @@ -107,6 +107,8 @@ The default is 1800 seconds. > .\" XXX > .\" .It Ic retrans timer Ar number > .\" XXX > +.It Ic preference Pq Ic low Ns | Ns Ic medium Ns | Ns Ic high > +Communicate router preference to clients. The default is medium. > .El > .Sh INTERFACES > A list of interfaces or interface groups to send advertisments on: > diff --git a/usr.sbin/rad/rad.h b/usr.sbin/rad/rad.h > index 2bbf7c8ed5c..cfaa5e88638 100644 > --- a/usr.sbin/rad/rad.h > +++ b/usr.sbin/rad/rad.h > @@ -92,6 +92,7 @@ struct ra_options_conf { > int cur_hl; /* current hop limit */ > int m_flag; /* managed address conf flag */ > int o_flag; /* other conf flag */ > + int preference; /* router preference (see RFC 4191 2.2) */ > int router_lifetime; /* default router lifetime */ > uint32_t reachable_time; > uint32_t retrans_timer; > > > On Wed, Aug 7, 2019 at 2:04 AM Florian Obser <[email protected]> wrote: > > > > On Tue, Aug 06, 2019 at 11:17:04PM +0200, Sebastian Benoit wrote: > > > Caleb([email protected]) on 2019.08.06 08:05:48 -0700: > > > > How do I publish default router preferences as defined in RFC 4191 > > > > (https://tools.ietf.org/html/rfc4191) using rad in OpenBSD 6.5? > > > > I've read the friendly rad.conf man page > > > > (https://man.openbsd.org/rad.conf.5) and scanned the source > > > > (https://github.com/openbsd/src/tree/master/usr.sbin/rad) with no > > > > success. > > > > > > You can't, because it was not implemented. > > > > > > That is, until now. > > > > > > I wrote a patch, which you can test if you like. It's completly untested > > > though. > > > > > > > needs more yak shaving > > > > > > > > diff --git usr.sbin/rad/frontend.c usr.sbin/rad/frontend.c > > > index 8178b058629..75723797fcf 100644 > > > --- usr.sbin/rad/frontend.c > > > +++ usr.sbin/rad/frontend.c > > > @@ -1016,6 +1016,8 @@ build_packet(struct ra_iface *ra_iface) > > > ra->nd_ra_flags_reserved |= ND_RA_FLAG_MANAGED; > > > if (ra_options_conf->o_flag) > > > ra->nd_ra_flags_reserved |= ND_RA_FLAG_OTHER; > > > + ra->nd_ra_flags_reserved |= > > > + ra_options_conf->preference; > > > if (ra_iface->removed) > > > /* tell clients that we are no longer a default router */ > > > ra->nd_ra_router_lifetime = 0; > > > @@ -1048,6 +1050,8 @@ build_packet(struct ra_iface *ra_iface) > > > if (ra_prefix_conf->aflag) > > > ndopt_pi->nd_opt_pi_flags_reserved |= > > > ND_OPT_PI_FLAG_AUTO; > > > + ndopt_pi->nd_opt_pi_flags_reserved |= > > > + ra_prefix_conf->preference; > > > > This is a prefix information option (type 3) not a route information option > > (type 24). > > Option 3 does not have a preference. > > > > > ndopt_pi->nd_opt_pi_valid_time = > > > htonl(ra_prefix_conf->vltime); > > > ndopt_pi->nd_opt_pi_preferred_time = > > > htonl(ra_prefix_conf->pltime); > > > diff --git usr.sbin/rad/parse.y usr.sbin/rad/parse.y > > > index 004e5e22f92..b004ab37356 100644 > > > --- usr.sbin/rad/parse.y > > > +++ usr.sbin/rad/parse.y > > > @@ -106,6 +106,7 @@ typedef struct { > > > union { > > > int64_t number; > > > char *string; > > > + short pref; > > > > eek, just treat it as a number? > > > > > } v; > > > int lineno; > > > } YYSTYPE; > > > @@ -117,11 +118,13 @@ typedef struct { > > > %token CONFIGURATION OTHER LIFETIME REACHABLE TIME RETRANS TIMER > > > %token AUTO PREFIX VALID PREFERRED LIFETIME ONLINK AUTONOMOUS > > > %token ADDRESS_CONFIGURATION DNS NAMESERVER SEARCH MTU > > > +%token PREFERENCE LOW MEDIUM HIGH > > > > > > %token <v.string> STRING > > > %token <v.number> NUMBER > > > %type <v.number> yesno > > > %type <v.string> string > > > +%type <v.pref> preftype > > > > > > %% > > > > > > @@ -213,6 +216,9 @@ ra_opt_block : DEFAULT ROUTER yesno { > > > | MTU NUMBER { > > > ra_options->mtu = $2; > > > } > > > + | PREFERENCE preftype { > > > + ra_options->preference = $2; > > > + } > > > | DNS dns_block > > > ; > > > > > > @@ -298,6 +304,19 @@ ra_prefixoptsl : VALID LIFETIME NUMBER { > > > | AUTONOMOUS ADDRESS_CONFIGURATION yesno { > > > ra_prefix_conf->aflag = $3; > > > } > > > + | PREFERENCE preftype { > > > + ra_prefix_conf->preference = $2; > > > + } > > > + ; > > > > see above, we are announcing prefix information, not route information > > > > > +preftype : LOW { > > > + $$ = RA_PREFIXOPT_PREF_LOW; > > > + } > > > + | MEDIUM { > > > + $$ = RA_PREFIXOPT_PREF_MEDIUM; > > > + } > > > + | HIGH { > > > + $$ = RA_PREFIXOPT_PREF_HIGH; > > > + } > > > > please use the defines from icmp6.h: > > > > #define ND_RA_FLAG_RTPREF_HIGH 0x08 /* 00001000 */ > > #define ND_RA_FLAG_RTPREF_MEDIUM 0x00 /* 00000000 */ > > #define ND_RA_FLAG_RTPREF_LOW 0x18 /* 00011000 */ > > #define ND_RA_FLAG_RTPREF_RSV 0x10 /* 00010000 */ > > > > > > > ; > > > dns_block : '{' optnl dnsopts_l '}' > > > | '{' optnl '}' > > > @@ -425,17 +444,21 @@ lookup(char *s) > > > {"configuration", CONFIGURATION}, > > > {"default", DEFAULT}, > > > {"dns", DNS}, > > > + {"high", HIGH}, > > > {"hop", HOP}, > > > {"include", INCLUDE}, > > > {"interface", RA_IFACE}, > > > {"lifetime", LIFETIME}, > > > {"limit", LIMIT}, > > > + {"low", LOW}, > > > {"managed", MANAGED}, > > > + {"medium", MEDIUM}, > > > {"mtu", MTU}, > > > {"nameserver", NAMESERVER}, > > > {"no", NO}, > > > {"on-link", ONLINK}, > > > {"other", OTHER}, > > > + {"preference", PREFERENCE}, > > > {"preferred", PREFERRED}, > > > {"prefix", PREFIX}, > > > {"reachable", REACHABLE}, > > > diff --git usr.sbin/rad/printconf.c usr.sbin/rad/printconf.c > > > index d42890da518..e063daaa19f 100644 > > > --- usr.sbin/rad/printconf.c > > > +++ usr.sbin/rad/printconf.c > > > @@ -34,6 +34,7 @@ > > > #include "rad.h" > > > > > > const char* yesno(int); > > > +const char* preference(short); > > > > make this an in ^ > > > > > void print_ra_options(const char*, const struct > > > ra_options_conf*); > > > void print_prefix_options(const char*, const struct > > > ra_prefix_conf*); > > > > > > @@ -43,6 +44,21 @@ yesno(int flag) > > > return flag ? "yes" : "no"; > > > } > > > > > > +const char* > > > +preference(short p) > > ^ and here > > > +{ > > > + switch (p) { > > > + case RA_PREFIXOPT_PREF_LOW: > > > + return "low"; > > > + case RA_PREFIXOPT_PREF_MEDIUM: > > > + return "medium"; > > > + case RA_PREFIXOPT_PREF_HIGH: > > > + return "high"; > > > + default: > > > + return "invalid"; > > > > use the defines from icmp6.h > > > > > + } > > > +} > > > + > > > void > > > print_ra_options(const char *indent, const struct ra_options_conf > > > *ra_options) > > > { > > > @@ -60,6 +76,9 @@ print_ra_options(const char *indent, const struct > > > ra_options_conf *ra_options) > > > printf("%sretrans timer %u\n", indent, ra_options->retrans_timer); > > > if (ra_options->mtu > 0) > > > printf("%smtu %u\n", indent, ra_options->mtu); > > > + if (ra_options->preference > 0) > > > > this does not work, if you set the default in the config file (medium) > > it will never get printed since it's 0, but maybe that's your > > intention? I'd store ND_RA_FLAG_RTPREF_RSV as default and map it to > > medium when building the packet. Then you can match on it here. > > > > > > > + printf("%spreference %s\n", indent, > > > + preference(ra_options->preference)); > > > > > > if (!SIMPLEQ_EMPTY(&ra_options->ra_rdnss_list) || > > > !SIMPLEQ_EMPTY(&ra_options->ra_dnssl_list)) { > > > @@ -95,6 +114,8 @@ print_prefix_options(const char *indent, const struct > > > ra_prefix_conf > > > printf("%son-link %s\n", indent, yesno(ra_prefix_conf->lflag)); > > > printf("%sautonomous address-configuration %s\n", indent, > > > yesno(ra_prefix_conf->aflag)); > > > + printf("%spreference %s\n", indent, > > > + preference(ra_prefix_conf->preference)); > > > > Prefix Information, not Route Information > > > > > } > > > > > > void > > > diff --git usr.sbin/rad/rad.conf.5 usr.sbin/rad/rad.conf.5 > > > index f651a715d1a..888a8f79b76 100644 > > > --- usr.sbin/rad/rad.conf.5 > > > +++ usr.sbin/rad/rad.conf.5 > > > @@ -107,6 +107,11 @@ The default is 1800 seconds. > > > .\" XXX > > > .\" .It Ic retrans timer Ar number > > > .\" XXX > > > +.It Ic preference Pq Ic low Ns | Ns Ic medium Ns | Ns Ic high > > > +Specify the router preference that is communicated to hosts through > > > +router advertisements. > > > +It can be used to communicate a prefered default router to IPv6 hosts. > > > +The default is medium. > > > .El > > > .Sh INTERFACES > > > A list of interfaces or interface groups to send advertisments on: > > > @@ -147,6 +152,9 @@ The default is 604800. > > > The valid lifetime (vltime) in seconds for addresses generated from this > > > prefix. > > > The default is 2592000. > > > +.It Ic preference Pq Ic low Ns | Ns Ic medium Ns | Ns Ic high > > > +The preference of the prefix is low, medium or high. > > > +The default is medium. > > > > Prefix Information vs. Route Informatiuon > > > > > .El > > > .Sh FILES > > > .Bl -tag -width "/etc/rad.conf" -compact > > > diff --git usr.sbin/rad/rad.h usr.sbin/rad/rad.h > > > index 2bbf7c8ed5c..9508783da2e 100644 > > > --- usr.sbin/rad/rad.h > > > +++ usr.sbin/rad/rad.h > > > @@ -93,6 +93,7 @@ struct ra_options_conf { > > > int m_flag; /* managed address conf > > > flag */ > > > int o_flag; /* other conf flag */ > > > int router_lifetime; /* default router lifetime > > > */ > > > + short preference; /* rfc4191 def. router > > > pref. */ > > > > ^ make it an int > > > > > uint32_t reachable_time; > > > uint32_t retrans_timer; > > > uint32_t mtu; > > > @@ -112,8 +113,17 @@ struct ra_prefix_conf { > > > uint32_t pltime; /* prefered > > > lifetime */ > > > int lflag; /* on-link flag*/ > > > int aflag; /* autonom. addr > > > flag */ > > > + short preference; /* preference > > > rfc4191 */ > > > > > > Prefix Information vs. Route Information > > > > > }; > > > > > > +/* > > > + RFC4191 preference values, in the middle of the 8bit reserved field. > > > + 01 High, 00 Medium (default), 11 Low, 10 Reserved - MUST NOT be sent > > > +*/ > > > +#define RA_PREFIXOPT_PREF_LOW 0x18 > > > +#define RA_PREFIXOPT_PREF_MEDIUM 0x00 > > > +#define RA_PREFIXOPT_PREF_HIGH 0x08 > > > + > > > > see above, use the defines from icmp6.h > > > > > struct ra_iface_conf { > > > SIMPLEQ_ENTRY(ra_iface_conf) entry; > > > struct ra_options_conf ra_options; > > > > -- > > I'm not entirely sure you are real.
