diff options
| -rw-r--r-- | sysdep/linux/netlink/netlink.c | 178 |
1 files changed, 157 insertions, 21 deletions
diff --git a/sysdep/linux/netlink/netlink.c b/sysdep/linux/netlink/netlink.c index 25bcadf..3eaa53a 100644 --- a/sysdep/linux/netlink/netlink.c +++ b/sysdep/linux/netlink/netlink.c @@ -238,37 +238,143 @@ nl_parse_attrs(struct rtattr *a, struct rtattr **k, int ksize) return 1; } -static void -nl_add_attr_u32(struct nlmsghdr *h, unsigned maxsize, int code, u32 data) +void +nl_add_attr(struct nlmsghdr *h, unsigned bufsize, unsigned code, + void *data, unsigned dlen) { - unsigned len = RTA_LENGTH(4); + unsigned len = RTA_LENGTH(dlen); + unsigned pos = NLMSG_ALIGN(h->nlmsg_len); struct rtattr *a; - if (NLMSG_ALIGN(h->nlmsg_len) + len > maxsize) - bug("nl_add_attr32: packet buffer overflow"); - a = (struct rtattr *)((char *)h + NLMSG_ALIGN(h->nlmsg_len)); + if (pos + len > bufsize) + bug("nl_add_attr: packet buffer overflow"); + a = (struct rtattr *)((char *)h + pos); a->rta_type = code; a->rta_len = len; - memcpy(RTA_DATA(a), &data, 4); - h->nlmsg_len = NLMSG_ALIGN(h->nlmsg_len) + len; + h->nlmsg_len = pos + len; + memcpy(RTA_DATA(a), data, dlen); } -static void -nl_add_attr_ipa(struct nlmsghdr *h, unsigned maxsize, int code, ip_addr ipa) +static inline void +nl_add_attr_u32(struct nlmsghdr *h, unsigned bufsize, int code, u32 data) { - unsigned len = RTA_LENGTH(sizeof(ipa)); - struct rtattr *a; + nl_add_attr(h, bufsize, code, &data, 4); +} - if (NLMSG_ALIGN(h->nlmsg_len) + len > maxsize) - bug("nl_add_attr_ipa: packet buffer overflow"); - a = (struct rtattr *)((char *)h + NLMSG_ALIGN(h->nlmsg_len)); - a->rta_type = code; - a->rta_len = len; +static inline void +nl_add_attr_ipa(struct nlmsghdr *h, unsigned bufsize, int code, ip_addr ipa) +{ ipa_hton(ipa); - memcpy(RTA_DATA(a), &ipa, sizeof(ipa)); - h->nlmsg_len = NLMSG_ALIGN(h->nlmsg_len) + len; + nl_add_attr(h, bufsize, code, &ipa, sizeof(ipa)); +} + +#define RTNH_SIZE (sizeof(struct rtnexthop) + sizeof(struct rtattr) + sizeof(ip_addr)) + +static inline void +add_mpnexthop(char *buf, ip_addr ipa, unsigned iface, unsigned char weight) +{ + struct rtnexthop *nh = (void *) buf; + struct rtattr *rt = (void *) (buf + sizeof(*nh)); + nh->rtnh_len = RTNH_SIZE; + nh->rtnh_flags = 0; + nh->rtnh_hops = weight; + nh->rtnh_ifindex = iface; + rt->rta_len = sizeof(*rt) + sizeof(ipa); + rt->rta_type = RTA_GATEWAY; + ipa_hton(ipa); + memcpy(buf + sizeof(*nh) + sizeof(*rt), &ipa, sizeof(ipa)); +} + + +static void +nl_add_multipath(struct nlmsghdr *h, unsigned bufsize, struct mpnh *nh) +{ + unsigned len = sizeof(struct rtattr); + unsigned pos = NLMSG_ALIGN(h->nlmsg_len); + char *buf = (char *)h + pos; + struct rtattr *rt = (void *) buf; + buf += len; + + for (; nh; nh = nh->next) + { + len += RTNH_SIZE; + if (pos + len > bufsize) + bug("nl_add_multipath: packet buffer overflow"); + + add_mpnexthop(buf, nh->gw, nh->iface->index, nh->weight); + buf += RTNH_SIZE; + } + + rt->rta_type = RTA_MULTIPATH; + rt->rta_len = len; + h->nlmsg_len = pos + len; } + +static struct mpnh * +nl_parse_multipath(struct krt_proto *p, struct rtattr *ra) +{ + /* Temporary buffer for multicast nexthops */ + static struct mpnh *nh_buffer; + static int nh_buf_size; /* in number of structures */ + static int nh_buf_used; + + struct rtattr *a[RTA_CACHEINFO+1]; + struct rtnexthop *nh = RTA_DATA(ra); + struct mpnh *rv, *first, **last; + int len = RTA_PAYLOAD(ra); + + first = NULL; + last = &first; + nh_buf_used = 0; + + while (len) + { + /* Use RTNH_OK(nh,len) ?? */ + if ((len < sizeof(*nh)) || (len < nh->rtnh_len)) + return NULL; + + if (nh_buf_used == nh_buf_size) + { + nh_buf_size = nh_buf_size ? (nh_buf_size * 2) : 4; + nh_buffer = xrealloc(nh_buffer, nh_buf_size * sizeof(struct mpnh)); + } + *last = rv = nh_buffer + nh_buf_used++; + rv->next = NULL; + last = &(rv->next); + + rv->weight = nh->rtnh_hops; + rv->iface = if_find_by_index(nh->rtnh_ifindex); + if (!rv->iface) + return NULL; + + /* Nonexistent RTNH_PAYLOAD ?? */ + nl_attr_len = nh->rtnh_len - RTNH_LENGTH(0); + nl_parse_attrs(RTNH_DATA(nh), 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); + + neighbor *ng = neigh_find2(&p->p, &rv->gw, rv->iface, + (nh->rtnh_flags & RTNH_F_ONLINK) ? NEF_ONLINK : 0); + if (!ng || (ng->scope == SCOPE_HOST)) + return NULL; + } + else + return NULL; + + len -= NLMSG_ALIGN(nh->rtnh_len); + nh = RTNH_NEXT(nh); + } + + return first; +} + + /* * Scanning of interfaces */ @@ -490,6 +596,7 @@ krt_capable(rte *e) case RTD_BLACKHOLE: case RTD_UNREACHABLE: case RTD_PROHIBIT: + case RTD_MULTIPATH: break; default: return 0; @@ -497,6 +604,15 @@ krt_capable(rte *e) return 1; } +static inline int +nh_bufsize(struct mpnh *nh) +{ + int rv = 0; + for (; nh != NULL; nh = nh->next) + rv += RTNH_SIZE; + return rv; +} + static void nl_send_route(struct krt_proto *p, rte *e, int new) { @@ -505,7 +621,7 @@ nl_send_route(struct krt_proto *p, rte *e, int new) struct { struct nlmsghdr h; struct rtmsg r; - char buf[128]; + char buf[64 + nh_bufsize(a->nexthops)]; } r; DBG("nl_send_route(%I/%d,new=%d)\n", net->n.prefix, net->n.pxlen, new); @@ -531,7 +647,7 @@ nl_send_route(struct krt_proto *p, rte *e, int new) /* a->iface != NULL checked in krt_capable() */ if (ipa_has_link_scope(a->gw)) - nl_add_attr_u32(&r.h, sizeof(r), RTA_OIF, a->iface->index); + nl_add_attr_u32(&r.h, sizeof(r), RTA_OIF, a->iface->index); break; case RTD_DEVICE: @@ -549,6 +665,10 @@ nl_send_route(struct krt_proto *p, rte *e, int new) case RTD_PROHIBIT: r.r.rtm_type = RTN_PROHIBIT; break; + case RTD_MULTIPATH: + r.r.rtm_type = RTN_UNICAST; + nl_add_multipath(&r.h, sizeof(r), a->nexthops); + break; default: bug("krt_capable inconsistent with nl_send_route"); } @@ -566,6 +686,7 @@ krt_set_notify(struct krt_proto *p, net *n UNUSED, rte *new, rte *old) nl_send_route(p, new, 1); } + #define SKIP(ARG...) do { DBG("KRT: Ignoring route - " ARG); return; } while(0) static void @@ -671,6 +792,21 @@ nl_parse_route(struct nlmsghdr *h, int scan) switch (i->rtm_type) { case RTN_UNICAST: + + if (a[RTA_MULTIPATH]) + { + ra.dest = RTD_MULTIPATH; + ra.nexthops = nl_parse_multipath(p, a[RTA_MULTIPATH]); + if (!ra.nexthops) + { + log(L_ERR "KRT: Received strange multipath route %I/%d", + net->n.prefix, net->n.pxlen); + return; + } + + break; + } + ra.iface = if_find_by_index(oif); if (!ra.iface) { |