diff options
| -rw-r--r-- | sysdep/linux/netlink.c | 187 |
1 files changed, 141 insertions, 46 deletions
diff --git a/sysdep/linux/netlink.c b/sysdep/linux/netlink.c index efbf41a6..640d1877 100644 --- a/sysdep/linux/netlink.c +++ b/sysdep/linux/netlink.c @@ -226,24 +226,98 @@ nl_checkin(struct nlmsghdr *h, int lsize) return NLMSG_DATA(h); } +struct nl_want_attrs { + u8 defined:1; + u8 checksize:1; + u8 size; +}; + + +#define BIRD_IFLA_MAX (IFLA_WIRELESS+1) + +static struct nl_want_attrs ifla_attr_want[BIRD_IFLA_MAX] = { + [IFLA_IFNAME] = { 1, 0, 0 }, + [IFLA_MTU] = { 1, 1, sizeof(u32) }, + [IFLA_WIRELESS] = { 1, 0, 0 }, +}; + + +#define BIRD_IFA_MAX (IFA_ANYCAST+1) + +#ifndef IPV6 +static struct nl_want_attrs ifa_attr_want4[BIRD_IFA_MAX] = { + [IFA_ADDRESS] = { 1, 1, sizeof(ip4_addr) }, + [IFA_LOCAL] = { 1, 1, sizeof(ip4_addr) }, + [IFA_BROADCAST] = { 1, 1, sizeof(ip4_addr) }, +}; +#else +static struct nl_want_attrs ifa_attr_want6[BIRD_IFA_MAX] = { + [IFA_ADDRESS] = { 1, 1, sizeof(ip6_addr) }, + [IFA_LOCAL] = { 1, 1, sizeof(ip6_addr) }, +}; +#endif + + +#define BIRD_RTA_MAX (RTA_TABLE+1) + +static struct nl_want_attrs mpnh_attr_want4[BIRD_RTA_MAX] = { + [RTA_GATEWAY] = { 1, 1, sizeof(ip4_addr) }, +}; + +#ifndef IPV6 +static struct nl_want_attrs rtm_attr_want4[BIRD_RTA_MAX] = { + [RTA_DST] = { 1, 1, sizeof(ip4_addr) }, + [RTA_OIF] = { 1, 1, sizeof(u32) }, + [RTA_GATEWAY] = { 1, 1, sizeof(ip4_addr) }, + [RTA_PRIORITY] = { 1, 1, sizeof(u32) }, + [RTA_PREFSRC] = { 1, 1, sizeof(ip4_addr) }, + [RTA_METRICS] = { 1, 0, 0 }, + [RTA_MULTIPATH] = { 1, 0, 0 }, + [RTA_FLOW] = { 1, 1, sizeof(u32) }, + [RTA_TABLE] = { 1, 1, sizeof(u32) }, +}; +#else +static struct nl_want_attrs rtm_attr_want6[BIRD_RTA_MAX] = { + [RTA_DST] = { 1, 1, sizeof(ip6_addr) }, + [RTA_IIF] = { 1, 1, sizeof(u32) }, + [RTA_OIF] = { 1, 1, sizeof(u32) }, + [RTA_GATEWAY] = { 1, 1, sizeof(ip6_addr) }, + [RTA_PRIORITY] = { 1, 1, sizeof(u32) }, + [RTA_PREFSRC] = { 1, 1, sizeof(ip6_addr) }, + [RTA_METRICS] = { 1, 0, 0 }, + [RTA_FLOW] = { 1, 1, sizeof(u32) }, + [RTA_TABLE] = { 1, 1, sizeof(u32) }, +}; +#endif + + static int -nl_parse_attrs(struct rtattr *a, struct rtattr **k, int ksize) +nl_parse_attrs(struct rtattr *a, struct nl_want_attrs *want, struct rtattr **k, int ksize) { int max = ksize / sizeof(struct rtattr *); bzero(k, ksize); - while (RTA_OK(a, nl_attr_len)) + + for ( ; RTA_OK(a, nl_attr_len); a = RTA_NEXT(a, nl_attr_len)) { - if (a->rta_type < max) - k[a->rta_type] = a; - a = RTA_NEXT(a, nl_attr_len); + if ((a->rta_type >= max) || !want[a->rta_type].defined) + continue; + + if (want[a->rta_type].checksize && (RTA_PAYLOAD(a) != want[a->rta_type].size)) + { + log(L_ERR "nl_parse_attrs: Malformed message received"); + return 0; + } + + k[a->rta_type] = a; } + if (nl_attr_len) { log(L_ERR "nl_parse_attrs: remnant of size %d", nl_attr_len); return 0; } - else - return 1; + + return 1; } static inline u32 rta_get_u32(struct rtattr *a) @@ -350,7 +424,7 @@ nl_parse_multipath(struct krt_proto *p, struct rtattr *ra) static int nh_buf_size; /* in number of structures */ static int nh_buf_used; - struct rtattr *a[RTA_CACHEINFO+1]; + struct rtattr *a[BIRD_RTA_MAX]; struct rtnexthop *nh = RTA_DATA(ra); struct mpnh *rv, *first, **last; int len = RTA_PAYLOAD(ra); @@ -381,12 +455,9 @@ nl_parse_multipath(struct krt_proto *p, struct rtattr *ra) /* Nonexistent RTNH_PAYLOAD ?? */ nl_attr_len = nh->rtnh_len - RTNH_LENGTH(0); - nl_parse_attrs(RTNH_DATA(nh), a, sizeof(a)); + nl_parse_attrs(RTNH_DATA(nh), mpnh_attr_want4, a, sizeof(a)); if (a[RTA_GATEWAY]) { - if (RTA_PAYLOAD(a[RTA_GATEWAY]) != sizeof(ip_addr)) - return NULL; - memcpy(&rv->gw, RTA_DATA(a[RTA_GATEWAY]), sizeof(ip_addr)); ipa_ntoh(rv->gw); @@ -455,7 +526,7 @@ static void nl_parse_link(struct nlmsghdr *h, int scan) { struct ifinfomsg *i; - struct rtattr *a[IFLA_WIRELESS+1]; + struct rtattr *a[BIRD_IFLA_MAX]; int new = h->nlmsg_type == RTM_NEWLINK; struct iface f = {}; struct iface *ifi; @@ -463,15 +534,23 @@ nl_parse_link(struct nlmsghdr *h, int scan) u32 mtu; uint fl; - if (!(i = nl_checkin(h, sizeof(*i))) || !nl_parse_attrs(IFLA_RTA(i), a, sizeof(a))) + if (!(i = nl_checkin(h, sizeof(*i))) || !nl_parse_attrs(IFLA_RTA(i), ifla_attr_want, a, sizeof(a))) return; - if (!a[IFLA_IFNAME] || RTA_PAYLOAD(a[IFLA_IFNAME]) < 2 || - !a[IFLA_MTU] || RTA_PAYLOAD(a[IFLA_MTU]) != 4) + if (!a[IFLA_IFNAME] || (RTA_PAYLOAD(a[IFLA_IFNAME]) < 2) || !a[IFLA_MTU]) { - if (scan || !a[IFLA_WIRELESS]) - log(L_ERR "nl_parse_link: Malformed message received"); + /* + * IFLA_IFNAME and IFLA_MTU are required, in fact, but there may also come + * a message with IFLA_WIRELESS set, where (e.g.) no IFLA_IFNAME exists. + * We simply ignore all such messages with IFLA_WIRELESS without notice. + */ + + if (a[IFLA_WIRELESS]) + return; + + log(L_ERR "KIF: Malformed message received"); return; } + name = RTA_DATA(a[IFLA_IFNAME]); mtu = rta_get_u32(a[IFLA_MTU]); @@ -522,26 +601,40 @@ static void nl_parse_addr(struct nlmsghdr *h, int scan) { struct ifaddrmsg *i; - struct rtattr *a[IFA_ANYCAST+1]; + struct rtattr *a[BIRD_IFA_MAX]; int new = h->nlmsg_type == RTM_NEWADDR; struct ifa ifa; struct iface *ifi; int scope; - if (!(i = nl_checkin(h, sizeof(*i))) || !nl_parse_attrs(IFA_RTA(i), a, sizeof(a))) + if (!(i = nl_checkin(h, sizeof(*i)))) return; - if (i->ifa_family != BIRD_AF) - return; - if (!a[IFA_ADDRESS] || RTA_PAYLOAD(a[IFA_ADDRESS]) != sizeof(ip_addr) -#ifdef IPV6 - || a[IFA_LOCAL] && RTA_PAYLOAD(a[IFA_LOCAL]) != sizeof(ip_addr) + + switch (i->ifa_family) + { +#ifndef IPV6 + case AF_INET: + if (!nl_parse_attrs(IFA_RTA(i), ifa_attr_want4, a, sizeof(a))) + return; + if (!a[IFA_LOCAL]) + { + log(L_ERR "KIF: Malformed message received (missing IFA_LOCAL)"); + return; + } + break; #else - || !a[IFA_LOCAL] || RTA_PAYLOAD(a[IFA_LOCAL]) != sizeof(ip_addr) - || (a[IFA_BROADCAST] && RTA_PAYLOAD(a[IFA_BROADCAST]) != sizeof(ip_addr)) + case AF_INET6: + if (!nl_parse_attrs(IFA_RTA(i), ifa_attr_want6, a, sizeof(a))) + return; + break; #endif - ) + default: + return; + } + + if (!a[IFA_ADDRESS]) { - log(L_ERR "nl_parse_addr: Malformed message received"); + log(L_ERR "KIF: Malformed message received (missing IFA_ADDRESS)"); return; } @@ -835,7 +928,7 @@ nl_parse_route(struct nlmsghdr *h, int scan) { struct krt_proto *p; struct rtmsg *i; - struct rtattr *a[RTA_TABLE+1]; + struct rtattr *a[BIRD_RTA_MAX]; int new = h->nlmsg_type == RTM_NEWROUTE; ip_addr dst = IPA_NONE; @@ -843,25 +936,27 @@ nl_parse_route(struct nlmsghdr *h, int scan) u32 table; int src; - if (!(i = nl_checkin(h, sizeof(*i))) || !nl_parse_attrs(RTM_RTA(i), a, sizeof(a))) + if (!(i = nl_checkin(h, sizeof(*i)))) return; - if (i->rtm_family != BIRD_AF) - return; - if ((a[RTA_DST] && RTA_PAYLOAD(a[RTA_DST]) != sizeof(ip_addr)) || -#ifdef IPV6 - (a[RTA_IIF] && RTA_PAYLOAD(a[RTA_IIF]) != 4) || -#endif - (a[RTA_OIF] && RTA_PAYLOAD(a[RTA_OIF]) != 4) || - (a[RTA_TABLE] && RTA_PAYLOAD(a[RTA_TABLE]) != 4) || - (a[RTA_GATEWAY] && RTA_PAYLOAD(a[RTA_GATEWAY]) != sizeof(ip_addr)) || - (a[RTA_PRIORITY] && RTA_PAYLOAD(a[RTA_PRIORITY]) != 4) || - (a[RTA_PREFSRC] && RTA_PAYLOAD(a[RTA_PREFSRC]) != sizeof(ip_addr)) || - (a[RTA_FLOW] && RTA_PAYLOAD(a[RTA_FLOW]) != 4)) + + switch (i->rtm_family) { - log(L_ERR "KRT: Malformed message received"); - return; +#ifndef IPV6 + case AF_INET: + if (!nl_parse_attrs(RTM_RTA(i), rtm_attr_want4, a, sizeof(a))) + return; + break; +#else + case AF_INET6: + if (!nl_parse_attrs(RTM_RTA(i), rtm_attr_want6, a, sizeof(a))) + return; + break; +#endif + default: + return; } + if (a[RTA_DST]) { memcpy(&dst, RTA_DATA(a[RTA_DST]), sizeof(dst)); @@ -938,7 +1033,7 @@ nl_parse_route(struct nlmsghdr *h, int scan) { case RTN_UNICAST: - if (a[RTA_MULTIPATH]) + if (a[RTA_MULTIPATH] && (i->rtm_family == AF_INET)) { ra.dest = RTD_MULTIPATH; ra.nexthops = nl_parse_multipath(p, a[RTA_MULTIPATH]); |