// SPDX-License-Identifier: GPL-2.0 /* * Inject packets with all sorts of encapsulation into the kernel. * * IPv4/IPv6 outer layer 3 * GRE/GUE/BARE outer layer 4, where bare is IPIP/SIT/IPv4-in-IPv6/.. * IPv4/IPv6 inner layer 3 */ #define _GNU_SOURCE #include <stddef.h> #include <arpa/inet.h> #include <asm/byteorder.h> #include <error.h> #include <errno.h> #include <linux/if_packet.h> #include <linux/if_ether.h> #include <linux/ipv6.h> #include <netinet/ip.h> #include <netinet/in.h> #include <netinet/udp.h> #include <poll.h> #include <stdbool.h> #include <stdlib.h> #include <stdio.h> #include <string.h> #include <sys/ioctl.h> #include <sys/socket.h> #include <sys/stat.h> #include <sys/time.h> #include <sys/types.h> #include <unistd.h> #define CFG_PORT_INNER 8000 /* Add some protocol definitions that do not exist in userspace */ struct grehdr { uint16_t unused; uint16_t protocol; } __attribute__((packed)); struct guehdr { union { struct { #if defined(__LITTLE_ENDIAN_BITFIELD) __u8 hlen:5, control:1, version:2; #elif defined (__BIG_ENDIAN_BITFIELD) __u8 version:2, control:1, hlen:5; #else #error "Please fix <asm/byteorder.h>" #endif __u8 proto_ctype; __be16 flags; }; __be32 word; }; }; static uint8_t cfg_dsfield_inner; static uint8_t cfg_dsfield_outer; static uint8_t cfg_encap_proto; static bool cfg_expect_failure = false; static int cfg_l3_extra = AF_UNSPEC; /* optional SIT prefix */ static int cfg_l3_inner = AF_UNSPEC; static int cfg_l3_outer = AF_UNSPEC; static int cfg_num_pkt = 10; static int cfg_num_secs = 0; static char cfg_payload_char = 'a'; static int cfg_payload_len = 100; static int cfg_port_gue = 6080; static bool cfg_only_rx; static bool cfg_only_tx; static int cfg_src_port = 9; static char buf[ETH_DATA_LEN]; #define INIT_ADDR4(name, addr4, port) \ static struct sockaddr_in name = { \ .sin_family = AF_INET, \ .sin_port = __constant_htons(port), \ .sin_addr.s_addr = __constant_htonl(addr4), \ }; #define INIT_ADDR6(name, addr6, port) \ static struct sockaddr_in6 name = { \ .sin6_family = AF_INET6, \ .sin6_port = __constant_htons(port), \ .sin6_addr = addr6, \ }; INIT_ADDR4(in_daddr4, INADDR_LOOPBACK, CFG_PORT_INNER) INIT_ADDR4(in_saddr4, INADDR_LOOPBACK + 2, 0) INIT_ADDR4(out_daddr4, INADDR_LOOPBACK, 0) INIT_ADDR4(out_saddr4, INADDR_LOOPBACK + 1, 0) INIT_ADDR4(extra_daddr4, INADDR_LOOPBACK, 0) INIT_ADDR4(extra_saddr4, INADDR_LOOPBACK + 1, 0) INIT_ADDR6(in_daddr6, IN6ADDR_LOOPBACK_INIT, CFG_PORT_INNER) INIT_ADDR6(in_saddr6, IN6ADDR_LOOPBACK_INIT, 0) INIT_ADDR6(out_daddr6, IN6ADDR_LOOPBACK_INIT, 0) INIT_ADDR6(out_saddr6, IN6ADDR_LOOPBACK_INIT, 0) INIT_ADDR6(extra_daddr6, IN6ADDR_LOOPBACK_INIT, 0) INIT_ADDR6(extra_saddr6, IN6ADDR_LOOPBACK_INIT, 0) static unsigned long util_gettime(void) { struct timeval tv; gettimeofday(&tv, NULL); return (tv.tv_sec * 1000) + (tv.tv_usec / 1000); } static void util_printaddr(const char *msg, struct sockaddr *addr) { unsigned long off = 0; char nbuf[INET6_ADDRSTRLEN]; switch (addr->sa_family) { case PF_INET: off = __builtin_offsetof(struct sockaddr_in, sin_addr); break; case PF_INET6: off = __builtin_offsetof(struct sockaddr_in6, sin6_addr); break; default: error(1, 0, "printaddr: unsupported family %u\n", addr->sa_family); } if (!inet_ntop(addr->sa_family, ((void *) addr) + off, nbuf, sizeof(nbuf))) error(1, errno, "inet_ntop"); fprintf(stderr, "%s: %s\n", msg, nbuf); } static unsigned long add_csum_hword(const uint16_t *start, int num_u16) { unsigned long sum = 0; int i; for (i = 0; i < num_u16; i++) sum += start[i]; return sum; } static uint16_t build_ip_csum(const uint16_t *start, int num_u16, unsigned long sum) { sum += add_csum_hword(start, num_u16); while (sum >> 16) sum = (sum & 0xffff) + (sum >> 16); return ~sum; } static void build_ipv4_header(void *header, uint8_t proto, uint32_t src, uint32_t dst, int payload_len, uint8_t tos) { struct iphdr *iph = header; iph->ihl = 5; iph->version = 4; iph->tos = tos; iph->ttl = 8; iph->tot_len = htons(sizeof(*iph) + payload_len); iph->id = htons(1337); iph->protocol = proto; iph->saddr = src; iph->daddr = dst; iph->check = build_ip_csum((void *) iph, iph->ihl << 1, 0); } static void ipv6_set_dsfield(struct ipv6hdr *ip6h, uint8_t dsfield) { uint16_t val, *ptr = (uint16_t *)ip6h; val = ntohs(*ptr); val &= 0xF00F; val |= ((uint16_t) dsfield) << 4; *ptr = htons(val); } static void build_ipv6_header(void *header, uint8_t proto, struct sockaddr_in6 *src, struct sockaddr_in6 *dst, int payload_len, uint8_t dsfield) { struct ipv6hdr *ip6h = header; ip6h->version = 6; ip6h->payload_len = htons(payload_len); ip6h->nexthdr = proto; ip6h->hop_limit = 8; ipv6_set_dsfield(ip6h, dsfield); memcpy(&ip6h->saddr, &src->sin6_addr, sizeof(ip6h->saddr)); memcpy(&ip6h->daddr, &dst->sin6_addr, sizeof(ip6h->daddr)); } static uint16_t build_udp_v4_csum(const struct iphdr *iph, const struct udphdr *udph, int num_words) { unsigned long pseudo_sum; int num_u16 = sizeof(iph->saddr); /* halfwords: twice byte len */ pseudo_sum = add_csum_hword((void *) &iph->saddr, num_u16); pseudo_sum += htons(IPPROTO_UDP); pseudo_sum += udph->len; return build_ip_csum((void *) udph, num_words, pseudo_sum); } static uint16_t build_udp_v6_csum(const struct ipv6hdr *ip6h, const struct udphdr *udph, int num_words) { unsigned long pseudo_sum; int num_u16 = sizeof(ip6h->saddr); /* halfwords: twice byte len */ pseudo_sum = add_csum_hword((void *) &ip6h->saddr, num_u16); pseudo_sum += htons(ip6h->nexthdr); pseudo_sum += ip6h->payload_len; return build_ip_csum((void *) udph, num_words, pseudo_sum); } static void build_udp_header(void *header, int payload_len, uint16_t dport, int family) { struct udphdr *udph = header; int len = sizeof(*udph) + payload_len; udph->source = htons(cfg_src_port); udph->dest = htons(dport); udph->len = htons(len); udph->check = 0; if (family == AF_INET) udph->check = build_udp_v4_csum(header - sizeof(struct iphdr), udph, len >> 1); else udph->check = build_udp_v6_csum(header - sizeof(struct ipv6hdr), udph, len >> 1); } static void build_gue_header(void *header, uint8_t proto) { struct guehdr *gueh = header; gueh->proto_ctype = proto; } static void build_gre_header(void *header, uint16_t proto) { struct grehdr *greh = header; greh->protocol = htons(proto); } static int l3_length(int family) { if (family == AF_INET) return sizeof(struct iphdr); else return sizeof(struct ipv6hdr); } static int build_packet(void) { int ol3_len = 0, ol4_len = 0, il3_len = 0, il4_len = 0; int el3_len = 0; if (cfg_l3_extra) el3_len = l3_length(cfg_l3_extra); /* calculate header offsets */ if (cfg_encap_proto) { ol3_len = l3_length(cfg_l3_outer); if (cfg_encap_proto == IPPROTO_GRE) ol4_len = sizeof(struct grehdr); else if (cfg_encap_proto == IPPROTO_UDP) ol4_len = sizeof(struct udphdr) + sizeof(struct guehdr); } il3_len = l3_length(cfg_l3_inner); il4_len = sizeof(struct udphdr); if (el3_len + ol3_len + ol4_len + il3_len + il4_len + cfg_payload_len >= sizeof(buf)) error(1, 0, "packet too large\n"); /* * Fill packet from inside out, to calculate correct checksums. * But create ip before udp headers, as udp uses ip for pseudo-sum. */ memset(buf + el3_len + ol3_len + ol4_len + il3_len + il4_len, cfg_payload_char, cfg_payload_len); /* add zero byte for udp csum padding */ buf[el3_len + ol3_len + ol4_len + il3_len + il4_len + cfg_payload_len] = 0; switch (cfg_l3_inner) { case PF_INET: build_ipv4_header(buf + el3_len + ol3_len + ol4_len, IPPROTO_UDP, in_saddr4.sin_addr.s_addr, in_daddr4.sin_addr.s_addr, il4_len + cfg_payload_len, cfg_dsfield_inner); break; case PF_INET6: build_ipv6_header(buf + el3_len + ol3_len + ol4_len, IPPROTO_UDP, &in_saddr6, &in_daddr6, il4_len + cfg_payload_len, cfg_dsfield_inner); break; } build_udp_header(buf + el3_len + ol3_len + ol4_len + il3_len, cfg_payload_len, CFG_PORT_INNER, cfg_l3_inner); if (!cfg_encap_proto) return il3_len + il4_len + cfg_payload_len; switch (cfg_l3_outer) { case PF_INET: build_ipv4_header(buf + el3_len, cfg_encap_proto, out_saddr4.sin_addr.s_addr, out_daddr4.sin_addr.s_addr, ol4_len + il3_len + il4_len + cfg_payload_len, cfg_dsfield_outer); break; case PF_INET6: build_ipv6_header(buf + el3_len, cfg_encap_proto, &out_saddr6, &out_daddr6, ol4_len + il3_len + il4_len + cfg_payload_len, cfg_dsfield_outer); break; } switch (cfg_encap_proto) { case IPPROTO_UDP: build_gue_header(buf + el3_len + ol3_len + ol4_len - sizeof(struct guehdr), cfg_l3_inner == PF_INET ? IPPROTO_IPIP : IPPROTO_IPV6); build_udp_header(buf + el3_len + ol3_len, sizeof(struct guehdr) + il3_len + il4_len + cfg_payload_len, cfg_port_gue, cfg_l3_outer); break; case IPPROTO_GRE: build_gre_header(buf + el3_len + ol3_len, cfg_l3_inner == PF_INET ? ETH_P_IP : ETH_P_IPV6); break; } switch (cfg_l3_extra) { case PF_INET: build_ipv4_header(buf, cfg_l3_outer == PF_INET ? IPPROTO_IPIP : IPPROTO_IPV6, extra_saddr4.sin_addr.s_addr, extra_daddr4.sin_addr.s_addr, ol3_len + ol4_len + il3_len + il4_len + cfg_payload_len, 0); break; case PF_INET6: build_ipv6_header(buf, cfg_l3_outer == PF_INET ? IPPROTO_IPIP : IPPROTO_IPV6, &extra_saddr6, &extra_daddr6, ol3_len + ol4_len + il3_len + il4_len + cfg_payload_len, 0); break; } return el3_len + ol3_len + ol4_len + il3_len + il4_len + cfg_payload_len; } /* sender transmits encapsulated over RAW or unencap'd over UDP */ static int setup_tx(void) { int family, fd, ret; if (cfg_l3_extra) family = cfg_l3_extra; else if (cfg_l3_outer) family = cfg_l3_outer; else family = cfg_l3_inner; fd = socket(family, SOCK_RAW, IPPROTO_RAW); if (fd == -1) error(1, errno, "socket tx"); if (cfg_l3_extra) { if (cfg_l3_extra == PF_INET) ret = connect(fd, (void *) &extra_daddr4, sizeof(extra_daddr4)); else ret = connect(fd, (void *) &extra_daddr6, sizeof(extra_daddr6)); if (ret) error(1, errno, "connect tx"); } else if (cfg_l3_outer) { /* connect to destination if not encapsulated */ if (cfg_l3_outer == PF_INET) ret = connect(fd, (void *) &out_daddr4, sizeof(out_daddr4)); else ret = connect(fd, (void *) &out_daddr6, sizeof(out_daddr6)); if (ret) error(1, errno, "connect tx"); } else { /* otherwise using loopback */ if (cfg_l3_inner == PF_INET) ret = connect(fd, (void *) &in_daddr4, sizeof(in_daddr4)); else ret = connect(fd, (void *) &in_daddr6, sizeof(in_daddr6)); if (ret) error(1, errno, "connect tx"); } return fd; } /* receiver reads unencapsulated UDP */ static int setup_rx(void) { int fd, ret; fd = socket(cfg_l3_inner, SOCK_DGRAM, 0); if (fd == -1) error(1, errno, "socket rx"); if (cfg_l3_inner == PF_INET) ret = bind(fd, (void *) &in_daddr4, sizeof(in_daddr4)); else ret = bind(fd, (void *) &in_daddr6, sizeof(in_daddr6)); if (ret) error(1, errno, "bind rx"); return fd; } static int do_tx(int fd, const char *pkt, int len) { int ret; ret = write(fd, pkt, len); if (ret == -1) error(1, errno, "send"); if (ret != len) error(1, errno, "send: len (%d < %d)\n", ret, len); return 1; } static int do_poll(int fd, short events, int timeout) { struct pollfd pfd; int ret; pfd.fd = fd; pfd.events = events; ret = poll(&pfd, 1, timeout); if (ret == -1) error(1, errno, "poll"); if (ret && !(pfd.revents & POLLIN)) error(1, errno, "poll: unexpected event 0x%x\n", pfd.revents); return ret; } static int do_rx(int fd) { char rbuf; int ret, num = 0; while (1) { ret = recv(fd, &rbuf, 1, MSG_DONTWAIT); if (ret == -1 && errno == EAGAIN) break; if (ret == -1) error(1, errno, "recv"); if (rbuf != cfg_payload_char) error(1, 0, "recv: payload mismatch"); num++; } return num; } static int do_main(void) { unsigned long tstop, treport, tcur; int fdt = -1, fdr = -1, len, tx = 0, rx = 0; if (!cfg_only_tx) fdr = setup_rx(); if (!cfg_only_rx) fdt = setup_tx(); len = build_packet(); tcur = util_gettime(); treport = tcur + 1000; tstop = tcur + (cfg_num_secs * 1000); while (1) { if (!cfg_only_rx) tx += do_tx(fdt, buf, len); if (!cfg_only_tx) rx += do_rx(fdr); if (cfg_num_secs) { tcur = util_gettime(); if (tcur >= tstop) break; if (tcur >= treport) { fprintf(stderr, "pkts: tx=%u rx=%u\n", tx, rx); tx = 0; rx = 0; treport = tcur + 1000; } } else { if (tx == cfg_num_pkt) break; } } /* read straggler packets, if any */ if (rx < tx) { tstop = util_gettime() + 100; while (rx < tx) { tcur = util_gettime(); if (tcur >= tstop) break; do_poll(fdr, POLLIN, tstop - tcur); rx += do_rx(fdr); } } fprintf(stderr, "pkts: tx=%u rx=%u\n", tx, rx); if (fdr != -1 && close(fdr)) error(1, errno, "close rx"); if (fdt != -1 && close(fdt)) error(1, errno, "close tx"); /* * success (== 0) only if received all packets * unless failure is expected, in which case none must arrive. */ if (cfg_expect_failure) return rx != 0; else return rx != tx; } static void __attribute__((noreturn)) usage(const char *filepath) { fprintf(stderr, "Usage: %s [-e gre|gue|bare|none] [-i 4|6] [-l len] " "[-O 4|6] [-o 4|6] [-n num] [-t secs] [-R] [-T] " "[-s <osrc> [-d <odst>] [-S <isrc>] [-D <idst>] " "[-x <otos>] [-X <itos>] [-f <isport>] [-F]\n", filepath); exit(1); } static void parse_addr(int family, void *addr, const char *optarg) { int ret; ret = inet_pton(family, optarg, addr); if (ret == -1) error(1, errno, "inet_pton"); if (ret == 0) error(1, 0, "inet_pton: bad string"); } static void parse_addr4(struct sockaddr_in *addr, const char *optarg) { parse_addr(AF_INET, &addr->sin_addr, optarg); } static void parse_addr6(struct sockaddr_in6 *addr, const char *optarg) { parse_addr(AF_INET6, &addr->sin6_addr, optarg); } static int parse_protocol_family(const char *filepath, const char *optarg) { if (!strcmp(optarg, "4")) return PF_INET; if (!strcmp(optarg, "6")) return PF_INET6; usage(filepath); } static void parse_opts(int argc, char **argv) { int c; while ((c = getopt(argc, argv, "d:D:e:f:Fhi:l:n:o:O:Rs:S:t:Tx:X:")) != -1) { switch (c) { case 'd': if (cfg_l3_outer == AF_UNSPEC) error(1, 0, "-d must be preceded by -o"); if (cfg_l3_outer == AF_INET) parse_addr4(&out_daddr4, optarg); else parse_addr6(&out_daddr6, optarg); break; case 'D': if (cfg_l3_inner == AF_UNSPEC) error(1, 0, "-D must be preceded by -i"); if (cfg_l3_inner == AF_INET) parse_addr4(&in_daddr4, optarg); else parse_addr6(&in_daddr6, optarg); break; case 'e': if (!strcmp(optarg, "gre")) cfg_encap_proto = IPPROTO_GRE; else if (!strcmp(optarg, "gue")) cfg_encap_proto = IPPROTO_UDP; else if (!strcmp(optarg, "bare")) cfg_encap_proto = IPPROTO_IPIP; else if (!strcmp(optarg, "none")) cfg_encap_proto = IPPROTO_IP; /* == 0 */ else usage(argv[0]); break; case 'f': cfg_src_port = strtol(optarg, NULL, 0); break; case 'F': cfg_expect_failure = true; break; case 'h': usage(argv[0]); break; case 'i': if (!strcmp(optarg, "4")) cfg_l3_inner = PF_INET; else if (!strcmp(optarg, "6")) cfg_l3_inner = PF_INET6; else usage(argv[0]); break; case 'l': cfg_payload_len = strtol(optarg, NULL, 0); break; case 'n': cfg_num_pkt = strtol(optarg, NULL, 0); break; case 'o': cfg_l3_outer = parse_protocol_family(argv[0], optarg); break; case 'O': cfg_l3_extra = parse_protocol_family(argv[0], optarg); break; case 'R': cfg_only_rx = true; break; case 's': if (cfg_l3_outer == AF_INET) parse_addr4(&out_saddr4, optarg); else parse_addr6(&out_saddr6, optarg); break; case 'S': if (cfg_l3_inner == AF_INET) parse_addr4(&in_saddr4, optarg); else parse_addr6(&in_saddr6, optarg); break; case 't': cfg_num_secs = strtol(optarg, NULL, 0); break; case 'T': cfg_only_tx = true; break; case 'x': cfg_dsfield_outer = strtol(optarg, NULL, 0); break; case 'X': cfg_dsfield_inner = strtol(optarg, NULL, 0); break; } } if (cfg_only_rx && cfg_only_tx) error(1, 0, "options: cannot combine rx-only and tx-only"); if (cfg_encap_proto && cfg_l3_outer == AF_UNSPEC) error(1, 0, "options: must specify outer with encap"); else if ((!cfg_encap_proto) && cfg_l3_outer != AF_UNSPEC) error(1, 0, "options: cannot combine no-encap and outer"); else if ((!cfg_encap_proto) && cfg_l3_extra != AF_UNSPEC) error(1, 0, "options: cannot combine no-encap and extra"); if (cfg_l3_inner == AF_UNSPEC) cfg_l3_inner = AF_INET6; if (cfg_l3_inner == AF_INET6 && cfg_encap_proto == IPPROTO_IPIP) cfg_encap_proto = IPPROTO_IPV6; /* RFC 6040 4.2: * on decap, if outer encountered congestion (CE == 0x3), * but inner cannot encode ECN (NoECT == 0x0), then drop packet. */ if (((cfg_dsfield_outer & 0x3) == 0x3) && ((cfg_dsfield_inner & 0x3) == 0x0)) cfg_expect_failure = true; } static void print_opts(void) { if (cfg_l3_inner == PF_INET6) { util_printaddr("inner.dest6", (void *) &in_daddr6); util_printaddr("inner.source6", (void *) &in_saddr6); } else { util_printaddr("inner.dest4", (void *) &in_daddr4); util_printaddr("inner.source4", (void *) &in_saddr4); } if (!cfg_l3_outer) return; fprintf(stderr, "encap proto: %u\n", cfg_encap_proto); if (cfg_l3_outer == PF_INET6) { util_printaddr("outer.dest6", (void *) &out_daddr6); util_printaddr("outer.source6", (void *) &out_saddr6); } else { util_printaddr("outer.dest4", (void *) &out_daddr4); util_printaddr("outer.source4", (void *) &out_saddr4); } if (!cfg_l3_extra) return; if (cfg_l3_outer == PF_INET6) { util_printaddr("extra.dest6", (void *) &extra_daddr6); util_printaddr("extra.source6", (void *) &extra_saddr6); } else { util_printaddr("extra.dest4", (void *) &extra_daddr4); util_printaddr("extra.source4", (void *) &extra_saddr4); } } int main(int argc, char **argv) { parse_opts(argc, argv); print_opts(); return do_main(); }