diff options
Diffstat (limited to 'samples/bpf/xdp_router_ipv4_user.c')
| -rw-r--r-- | samples/bpf/xdp_router_ipv4_user.c | 741 |
1 files changed, 741 insertions, 0 deletions
diff --git a/samples/bpf/xdp_router_ipv4_user.c b/samples/bpf/xdp_router_ipv4_user.c new file mode 100644 index 000000000..c2da1b51f --- /dev/null +++ b/samples/bpf/xdp_router_ipv4_user.c @@ -0,0 +1,741 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (C) 2017 Cavium, Inc. + */ +#include <linux/bpf.h> +#include <linux/netlink.h> +#include <linux/rtnetlink.h> +#include <assert.h> +#include <errno.h> +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/socket.h> +#include <unistd.h> +#include <bpf/bpf.h> +#include <arpa/inet.h> +#include <fcntl.h> +#include <poll.h> +#include <net/if.h> +#include <netdb.h> +#include <sys/ioctl.h> +#include <sys/syscall.h> +#include "bpf_util.h" +#include <bpf/libbpf.h> +#include <sys/resource.h> +#include <libgen.h> + +int sock, sock_arp, flags = XDP_FLAGS_UPDATE_IF_NOEXIST; +static int total_ifindex; +static int *ifindex_list; +static __u32 *prog_id_list; +char buf[8192]; +static int lpm_map_fd; +static int rxcnt_map_fd; +static int arp_table_map_fd; +static int exact_match_map_fd; +static int tx_port_map_fd; + +static int get_route_table(int rtm_family); +static void int_exit(int sig) +{ + __u32 prog_id = 0; + int i = 0; + + for (i = 0; i < total_ifindex; i++) { + if (bpf_get_link_xdp_id(ifindex_list[i], &prog_id, flags)) { + printf("bpf_get_link_xdp_id on iface %d failed\n", + ifindex_list[i]); + exit(1); + } + if (prog_id_list[i] == prog_id) + bpf_set_link_xdp_fd(ifindex_list[i], -1, flags); + else if (!prog_id) + printf("couldn't find a prog id on iface %d\n", + ifindex_list[i]); + else + printf("program on iface %d changed, not removing\n", + ifindex_list[i]); + prog_id = 0; + } + exit(0); +} + +static void close_and_exit(int sig) +{ + close(sock); + close(sock_arp); + + int_exit(0); +} + +/* Get the mac address of the interface given interface name */ +static __be64 getmac(char *iface) +{ + struct ifreq ifr; + __be64 mac = 0; + int fd, i; + + fd = socket(AF_INET, SOCK_DGRAM, 0); + ifr.ifr_addr.sa_family = AF_INET; + strncpy(ifr.ifr_name, iface, IFNAMSIZ - 1); + if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) { + printf("ioctl failed leaving....\n"); + return -1; + } + for (i = 0; i < 6 ; i++) + *((__u8 *)&mac + i) = (__u8)ifr.ifr_hwaddr.sa_data[i]; + close(fd); + return mac; +} + +static int recv_msg(struct sockaddr_nl sock_addr, int sock) +{ + struct nlmsghdr *nh; + int len, nll = 0; + char *buf_ptr; + + buf_ptr = buf; + while (1) { + len = recv(sock, buf_ptr, sizeof(buf) - nll, 0); + if (len < 0) + return len; + + nh = (struct nlmsghdr *)buf_ptr; + + if (nh->nlmsg_type == NLMSG_DONE) + break; + buf_ptr += len; + nll += len; + if ((sock_addr.nl_groups & RTMGRP_NEIGH) == RTMGRP_NEIGH) + break; + + if ((sock_addr.nl_groups & RTMGRP_IPV4_ROUTE) == RTMGRP_IPV4_ROUTE) + break; + } + return nll; +} + +/* Function to parse the route entry returned by netlink + * Updates the route entry related map entries + */ +static void read_route(struct nlmsghdr *nh, int nll) +{ + char dsts[24], gws[24], ifs[16], dsts_len[24], metrics[24]; + struct bpf_lpm_trie_key *prefix_key; + struct rtattr *rt_attr; + struct rtmsg *rt_msg; + int rtm_family; + int rtl; + int i; + struct route_table { + int dst_len, iface, metric; + char *iface_name; + __be32 dst, gw; + __be64 mac; + } route; + struct arp_table { + __be64 mac; + __be32 dst; + }; + + struct direct_map { + struct arp_table arp; + int ifindex; + __be64 mac; + } direct_entry; + + if (nh->nlmsg_type == RTM_DELROUTE) + printf("DELETING Route entry\n"); + else if (nh->nlmsg_type == RTM_GETROUTE) + printf("READING Route entry\n"); + else if (nh->nlmsg_type == RTM_NEWROUTE) + printf("NEW Route entry\n"); + else + printf("%d\n", nh->nlmsg_type); + + memset(&route, 0, sizeof(route)); + printf("Destination\t\tGateway\t\tGenmask\t\tMetric\t\tIface\n"); + for (; NLMSG_OK(nh, nll); nh = NLMSG_NEXT(nh, nll)) { + rt_msg = (struct rtmsg *)NLMSG_DATA(nh); + rtm_family = rt_msg->rtm_family; + if (rtm_family == AF_INET) + if (rt_msg->rtm_table != RT_TABLE_MAIN) + continue; + rt_attr = (struct rtattr *)RTM_RTA(rt_msg); + rtl = RTM_PAYLOAD(nh); + + for (; RTA_OK(rt_attr, rtl); rt_attr = RTA_NEXT(rt_attr, rtl)) { + switch (rt_attr->rta_type) { + case NDA_DST: + sprintf(dsts, "%u", + (*((__be32 *)RTA_DATA(rt_attr)))); + break; + case RTA_GATEWAY: + sprintf(gws, "%u", + *((__be32 *)RTA_DATA(rt_attr))); + break; + case RTA_OIF: + sprintf(ifs, "%u", + *((int *)RTA_DATA(rt_attr))); + break; + case RTA_METRICS: + sprintf(metrics, "%u", + *((int *)RTA_DATA(rt_attr))); + default: + break; + } + } + sprintf(dsts_len, "%d", rt_msg->rtm_dst_len); + route.dst = atoi(dsts); + route.dst_len = atoi(dsts_len); + route.gw = atoi(gws); + route.iface = atoi(ifs); + route.metric = atoi(metrics); + route.iface_name = alloca(sizeof(char *) * IFNAMSIZ); + route.iface_name = if_indextoname(route.iface, route.iface_name); + route.mac = getmac(route.iface_name); + if (route.mac == -1) + int_exit(0); + assert(bpf_map_update_elem(tx_port_map_fd, + &route.iface, &route.iface, 0) == 0); + if (rtm_family == AF_INET) { + struct trie_value { + __u8 prefix[4]; + __be64 value; + int ifindex; + int metric; + __be32 gw; + } *prefix_value; + + prefix_key = alloca(sizeof(*prefix_key) + 3); + prefix_value = alloca(sizeof(*prefix_value)); + + prefix_key->prefixlen = 32; + prefix_key->prefixlen = route.dst_len; + direct_entry.mac = route.mac & 0xffffffffffff; + direct_entry.ifindex = route.iface; + direct_entry.arp.mac = 0; + direct_entry.arp.dst = 0; + if (route.dst_len == 32) { + if (nh->nlmsg_type == RTM_DELROUTE) { + assert(bpf_map_delete_elem(exact_match_map_fd, + &route.dst) == 0); + } else { + if (bpf_map_lookup_elem(arp_table_map_fd, + &route.dst, + &direct_entry.arp.mac) == 0) + direct_entry.arp.dst = route.dst; + assert(bpf_map_update_elem(exact_match_map_fd, + &route.dst, + &direct_entry, 0) == 0); + } + } + for (i = 0; i < 4; i++) + prefix_key->data[i] = (route.dst >> i * 8) & 0xff; + + printf("%3d.%d.%d.%d\t\t%3x\t\t%d\t\t%d\t\t%s\n", + (int)prefix_key->data[0], + (int)prefix_key->data[1], + (int)prefix_key->data[2], + (int)prefix_key->data[3], + route.gw, route.dst_len, + route.metric, + route.iface_name); + if (bpf_map_lookup_elem(lpm_map_fd, prefix_key, + prefix_value) < 0) { + for (i = 0; i < 4; i++) + prefix_value->prefix[i] = prefix_key->data[i]; + prefix_value->value = route.mac & 0xffffffffffff; + prefix_value->ifindex = route.iface; + prefix_value->gw = route.gw; + prefix_value->metric = route.metric; + + assert(bpf_map_update_elem(lpm_map_fd, + prefix_key, + prefix_value, 0 + ) == 0); + } else { + if (nh->nlmsg_type == RTM_DELROUTE) { + printf("deleting entry\n"); + printf("prefix key=%d.%d.%d.%d/%d", + prefix_key->data[0], + prefix_key->data[1], + prefix_key->data[2], + prefix_key->data[3], + prefix_key->prefixlen); + assert(bpf_map_delete_elem(lpm_map_fd, + prefix_key + ) == 0); + /* Rereading the route table to check if + * there is an entry with the same + * prefix but a different metric as the + * deleted enty. + */ + get_route_table(AF_INET); + } else if (prefix_key->data[0] == + prefix_value->prefix[0] && + prefix_key->data[1] == + prefix_value->prefix[1] && + prefix_key->data[2] == + prefix_value->prefix[2] && + prefix_key->data[3] == + prefix_value->prefix[3] && + route.metric >= prefix_value->metric) { + continue; + } else { + for (i = 0; i < 4; i++) + prefix_value->prefix[i] = + prefix_key->data[i]; + prefix_value->value = + route.mac & 0xffffffffffff; + prefix_value->ifindex = route.iface; + prefix_value->gw = route.gw; + prefix_value->metric = route.metric; + assert(bpf_map_update_elem(lpm_map_fd, + prefix_key, + prefix_value, + 0) == 0); + } + } + } + memset(&route, 0, sizeof(route)); + memset(dsts, 0, sizeof(dsts)); + memset(dsts_len, 0, sizeof(dsts_len)); + memset(gws, 0, sizeof(gws)); + memset(ifs, 0, sizeof(ifs)); + memset(&route, 0, sizeof(route)); + } +} + +/* Function to read the existing route table when the process is launched*/ +static int get_route_table(int rtm_family) +{ + struct sockaddr_nl sa; + struct nlmsghdr *nh; + int sock, seq = 0; + struct msghdr msg; + struct iovec iov; + int ret = 0; + int nll; + + struct { + struct nlmsghdr nl; + struct rtmsg rt; + char buf[8192]; + } req; + + sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); + if (sock < 0) { + printf("open netlink socket: %s\n", strerror(errno)); + return -1; + } + memset(&sa, 0, sizeof(sa)); + sa.nl_family = AF_NETLINK; + if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) { + printf("bind to netlink: %s\n", strerror(errno)); + ret = -1; + goto cleanup; + } + memset(&req, 0, sizeof(req)); + req.nl.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg)); + req.nl.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP; + req.nl.nlmsg_type = RTM_GETROUTE; + + req.rt.rtm_family = rtm_family; + req.rt.rtm_table = RT_TABLE_MAIN; + req.nl.nlmsg_pid = 0; + req.nl.nlmsg_seq = ++seq; + memset(&msg, 0, sizeof(msg)); + iov.iov_base = (void *)&req.nl; + iov.iov_len = req.nl.nlmsg_len; + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + ret = sendmsg(sock, &msg, 0); + if (ret < 0) { + printf("send to netlink: %s\n", strerror(errno)); + ret = -1; + goto cleanup; + } + memset(buf, 0, sizeof(buf)); + nll = recv_msg(sa, sock); + if (nll < 0) { + printf("recv from netlink: %s\n", strerror(nll)); + ret = -1; + goto cleanup; + } + nh = (struct nlmsghdr *)buf; + read_route(nh, nll); +cleanup: + close(sock); + return ret; +} + +/* Function to parse the arp entry returned by netlink + * Updates the arp entry related map entries + */ +static void read_arp(struct nlmsghdr *nh, int nll) +{ + struct rtattr *rt_attr; + char dsts[24], mac[24]; + struct ndmsg *rt_msg; + int rtl, ndm_family; + + struct arp_table { + __be64 mac; + __be32 dst; + } arp_entry; + struct direct_map { + struct arp_table arp; + int ifindex; + __be64 mac; + } direct_entry; + + if (nh->nlmsg_type == RTM_GETNEIGH) + printf("READING arp entry\n"); + printf("Address\tHwAddress\n"); + for (; NLMSG_OK(nh, nll); nh = NLMSG_NEXT(nh, nll)) { + rt_msg = (struct ndmsg *)NLMSG_DATA(nh); + rt_attr = (struct rtattr *)RTM_RTA(rt_msg); + ndm_family = rt_msg->ndm_family; + rtl = RTM_PAYLOAD(nh); + for (; RTA_OK(rt_attr, rtl); rt_attr = RTA_NEXT(rt_attr, rtl)) { + switch (rt_attr->rta_type) { + case NDA_DST: + sprintf(dsts, "%u", + *((__be32 *)RTA_DATA(rt_attr))); + break; + case NDA_LLADDR: + sprintf(mac, "%lld", + *((__be64 *)RTA_DATA(rt_attr))); + break; + default: + break; + } + } + arp_entry.dst = atoi(dsts); + arp_entry.mac = atol(mac); + printf("%x\t\t%llx\n", arp_entry.dst, arp_entry.mac); + if (ndm_family == AF_INET) { + if (bpf_map_lookup_elem(exact_match_map_fd, + &arp_entry.dst, + &direct_entry) == 0) { + if (nh->nlmsg_type == RTM_DELNEIGH) { + direct_entry.arp.dst = 0; + direct_entry.arp.mac = 0; + } else if (nh->nlmsg_type == RTM_NEWNEIGH) { + direct_entry.arp.dst = arp_entry.dst; + direct_entry.arp.mac = arp_entry.mac; + } + assert(bpf_map_update_elem(exact_match_map_fd, + &arp_entry.dst, + &direct_entry, 0 + ) == 0); + memset(&direct_entry, 0, sizeof(direct_entry)); + } + if (nh->nlmsg_type == RTM_DELNEIGH) { + assert(bpf_map_delete_elem(arp_table_map_fd, + &arp_entry.dst) == 0); + } else if (nh->nlmsg_type == RTM_NEWNEIGH) { + assert(bpf_map_update_elem(arp_table_map_fd, + &arp_entry.dst, + &arp_entry.mac, 0 + ) == 0); + } + } + memset(&arp_entry, 0, sizeof(arp_entry)); + memset(dsts, 0, sizeof(dsts)); + } +} + +/* Function to read the existing arp table when the process is launched*/ +static int get_arp_table(int rtm_family) +{ + struct sockaddr_nl sa; + struct nlmsghdr *nh; + int sock, seq = 0; + struct msghdr msg; + struct iovec iov; + int ret = 0; + int nll; + struct { + struct nlmsghdr nl; + struct ndmsg rt; + char buf[8192]; + } req; + + sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); + if (sock < 0) { + printf("open netlink socket: %s\n", strerror(errno)); + return -1; + } + memset(&sa, 0, sizeof(sa)); + sa.nl_family = AF_NETLINK; + if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) { + printf("bind to netlink: %s\n", strerror(errno)); + ret = -1; + goto cleanup; + } + memset(&req, 0, sizeof(req)); + req.nl.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg)); + req.nl.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP; + req.nl.nlmsg_type = RTM_GETNEIGH; + req.rt.ndm_state = NUD_REACHABLE; + req.rt.ndm_family = rtm_family; + req.nl.nlmsg_pid = 0; + req.nl.nlmsg_seq = ++seq; + memset(&msg, 0, sizeof(msg)); + iov.iov_base = (void *)&req.nl; + iov.iov_len = req.nl.nlmsg_len; + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + ret = sendmsg(sock, &msg, 0); + if (ret < 0) { + printf("send to netlink: %s\n", strerror(errno)); + ret = -1; + goto cleanup; + } + memset(buf, 0, sizeof(buf)); + nll = recv_msg(sa, sock); + if (nll < 0) { + printf("recv from netlink: %s\n", strerror(nll)); + ret = -1; + goto cleanup; + } + nh = (struct nlmsghdr *)buf; + read_arp(nh, nll); +cleanup: + close(sock); + return ret; +} + +/* Function to keep track and update changes in route and arp table + * Give regular statistics of packets forwarded + */ +static int monitor_route(void) +{ + unsigned int nr_cpus = bpf_num_possible_cpus(); + const unsigned int nr_keys = 256; + struct pollfd fds_route, fds_arp; + __u64 prev[nr_keys][nr_cpus]; + struct sockaddr_nl la, lr; + __u64 values[nr_cpus]; + struct nlmsghdr *nh; + int nll, ret = 0; + int interval = 5; + __u32 key; + int i; + + sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); + if (sock < 0) { + printf("open netlink socket: %s\n", strerror(errno)); + return -1; + } + + fcntl(sock, F_SETFL, O_NONBLOCK); + memset(&lr, 0, sizeof(lr)); + lr.nl_family = AF_NETLINK; + lr.nl_groups = RTMGRP_IPV6_ROUTE | RTMGRP_IPV4_ROUTE | RTMGRP_NOTIFY; + if (bind(sock, (struct sockaddr *)&lr, sizeof(lr)) < 0) { + printf("bind to netlink: %s\n", strerror(errno)); + ret = -1; + goto cleanup; + } + fds_route.fd = sock; + fds_route.events = POLL_IN; + + sock_arp = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); + if (sock_arp < 0) { + printf("open netlink socket: %s\n", strerror(errno)); + return -1; + } + + fcntl(sock_arp, F_SETFL, O_NONBLOCK); + memset(&la, 0, sizeof(la)); + la.nl_family = AF_NETLINK; + la.nl_groups = RTMGRP_NEIGH | RTMGRP_NOTIFY; + if (bind(sock_arp, (struct sockaddr *)&la, sizeof(la)) < 0) { + printf("bind to netlink: %s\n", strerror(errno)); + ret = -1; + goto cleanup; + } + fds_arp.fd = sock_arp; + fds_arp.events = POLL_IN; + + memset(prev, 0, sizeof(prev)); + do { + signal(SIGINT, close_and_exit); + signal(SIGTERM, close_and_exit); + + sleep(interval); + for (key = 0; key < nr_keys; key++) { + __u64 sum = 0; + + assert(bpf_map_lookup_elem(rxcnt_map_fd, + &key, values) == 0); + for (i = 0; i < nr_cpus; i++) + sum += (values[i] - prev[key][i]); + if (sum) + printf("proto %u: %10llu pkt/s\n", + key, sum / interval); + memcpy(prev[key], values, sizeof(values)); + } + + memset(buf, 0, sizeof(buf)); + if (poll(&fds_route, 1, 3) == POLL_IN) { + nll = recv_msg(lr, sock); + if (nll < 0) { + printf("recv from netlink: %s\n", strerror(nll)); + ret = -1; + goto cleanup; + } + + nh = (struct nlmsghdr *)buf; + printf("Routing table updated.\n"); + read_route(nh, nll); + } + memset(buf, 0, sizeof(buf)); + if (poll(&fds_arp, 1, 3) == POLL_IN) { + nll = recv_msg(la, sock_arp); + if (nll < 0) { + printf("recv from netlink: %s\n", strerror(nll)); + ret = -1; + goto cleanup; + } + + nh = (struct nlmsghdr *)buf; + read_arp(nh, nll); + } + + } while (1); +cleanup: + close(sock); + return ret; +} + +static void usage(const char *prog) +{ + fprintf(stderr, + "%s: %s [OPTS] interface name list\n\n" + "OPTS:\n" + " -S use skb-mode\n" + " -F force loading prog\n", + __func__, prog); +} + +int main(int ac, char **argv) +{ + struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY}; + struct bpf_prog_load_attr prog_load_attr = { + .prog_type = BPF_PROG_TYPE_XDP, + }; + struct bpf_prog_info info = {}; + __u32 info_len = sizeof(info); + const char *optstr = "SF"; + struct bpf_object *obj; + char filename[256]; + char **ifname_list; + int prog_fd, opt; + int err, i = 1; + + snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + prog_load_attr.file = filename; + + total_ifindex = ac - 1; + ifname_list = (argv + 1); + + while ((opt = getopt(ac, argv, optstr)) != -1) { + switch (opt) { + case 'S': + flags |= XDP_FLAGS_SKB_MODE; + total_ifindex--; + ifname_list++; + break; + case 'F': + flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST; + total_ifindex--; + ifname_list++; + break; + default: + usage(basename(argv[0])); + return 1; + } + } + + if (!(flags & XDP_FLAGS_SKB_MODE)) + flags |= XDP_FLAGS_DRV_MODE; + + if (optind == ac) { + usage(basename(argv[0])); + return 1; + } + + if (setrlimit(RLIMIT_MEMLOCK, &r)) { + perror("setrlimit(RLIMIT_MEMLOCK)"); + return 1; + } + + if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd)) + return 1; + + printf("\n**************loading bpf file*********************\n\n\n"); + if (!prog_fd) { + printf("bpf_prog_load_xattr: %s\n", strerror(errno)); + return 1; + } + + lpm_map_fd = bpf_object__find_map_fd_by_name(obj, "lpm_map"); + rxcnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rxcnt"); + arp_table_map_fd = bpf_object__find_map_fd_by_name(obj, "arp_table"); + exact_match_map_fd = bpf_object__find_map_fd_by_name(obj, + "exact_match"); + tx_port_map_fd = bpf_object__find_map_fd_by_name(obj, "tx_port"); + if (lpm_map_fd < 0 || rxcnt_map_fd < 0 || arp_table_map_fd < 0 || + exact_match_map_fd < 0 || tx_port_map_fd < 0) { + printf("bpf_object__find_map_fd_by_name failed\n"); + return 1; + } + + ifindex_list = (int *)calloc(total_ifindex, sizeof(int *)); + for (i = 0; i < total_ifindex; i++) { + ifindex_list[i] = if_nametoindex(ifname_list[i]); + if (!ifindex_list[i]) { + printf("Couldn't translate interface name: %s", + strerror(errno)); + return 1; + } + } + prog_id_list = (__u32 *)calloc(total_ifindex, sizeof(__u32 *)); + for (i = 0; i < total_ifindex; i++) { + if (bpf_set_link_xdp_fd(ifindex_list[i], prog_fd, flags) < 0) { + printf("link set xdp fd failed\n"); + int recovery_index = i; + + for (i = 0; i < recovery_index; i++) + bpf_set_link_xdp_fd(ifindex_list[i], -1, flags); + + return 1; + } + err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len); + if (err) { + printf("can't get prog info - %s\n", strerror(errno)); + return err; + } + prog_id_list[i] = info.id; + memset(&info, 0, sizeof(info)); + printf("Attached to %d\n", ifindex_list[i]); + } + signal(SIGINT, int_exit); + signal(SIGTERM, int_exit); + + printf("*******************ROUTE TABLE*************************\n\n\n"); + get_route_table(AF_INET); + printf("*******************ARP TABLE***************************\n\n\n"); + get_arp_table(AF_INET); + if (monitor_route() < 0) { + printf("Error in receiving route update"); + return 1; + } + + return 0; +} |