diff options
Diffstat (limited to 'tools/testing/selftests/bpf/network_helpers.c')
| -rw-r--r-- | tools/testing/selftests/bpf/network_helpers.c | 602 |
1 files changed, 543 insertions, 59 deletions
diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c index e0cba4178e41..27784946b01b 100644 --- a/tools/testing/selftests/bpf/network_helpers.c +++ b/tools/testing/selftests/bpf/network_helpers.c @@ -11,17 +11,31 @@ #include <arpa/inet.h> #include <sys/mount.h> #include <sys/stat.h> +#include <sys/types.h> #include <sys/un.h> +#include <sys/eventfd.h> #include <linux/err.h> #include <linux/in.h> #include <linux/in6.h> #include <linux/limits.h> +#include <linux/ip.h> +#include <linux/udp.h> +#include <netinet/tcp.h> +#include <net/if.h> + #include "bpf_util.h" #include "network_helpers.h" #include "test_progs.h" +#ifdef TRAFFIC_MONITOR +/* Prevent pcap.h from including pcap/bpf.h and causing conflicts */ +#define PCAP_DONT_INCLUDE_PCAP_BPF_H 1 +#include <pcap/pcap.h> +#include <pcap/dlt.h> +#endif + #ifndef IPPROTO_MPTCP #define IPPROTO_MPTCP 262 #endif @@ -80,12 +94,15 @@ int settimeo(int fd, int timeout_ms) #define save_errno_close(fd) ({ int __save = errno; close(fd); errno = __save; }) -static int __start_server(int type, const struct sockaddr *addr, socklen_t addrlen, - const struct network_helper_opts *opts) +int start_server_addr(int type, const struct sockaddr_storage *addr, socklen_t addrlen, + const struct network_helper_opts *opts) { int fd; - fd = socket(addr->sa_family, type, opts->proto); + if (!opts) + opts = &default_opts; + + fd = socket(addr->ss_family, type, opts->proto); if (fd < 0) { log_err("Failed to create server socket"); return -1; @@ -100,7 +117,7 @@ static int __start_server(int type, const struct sockaddr *addr, socklen_t addrl goto error_close; } - if (bind(fd, addr, addrlen) < 0) { + if (bind(fd, (struct sockaddr *)addr, addrlen) < 0) { log_err("Failed to bind socket"); goto error_close; } @@ -131,7 +148,7 @@ int start_server_str(int family, int type, const char *addr_str, __u16 port, if (make_sockaddr(family, addr_str, port, &addr, &addrlen)) return -1; - return __start_server(type, (struct sockaddr *)&addr, addrlen, opts); + return start_server_addr(type, &addr, addrlen, opts); } int start_server(int family, int type, const char *addr_str, __u16 port, @@ -173,7 +190,7 @@ int *start_reuseport_server(int family, int type, const char *addr_str, if (!fds) return NULL; - fds[0] = __start_server(type, (struct sockaddr *)&addr, addrlen, &opts); + fds[0] = start_server_addr(type, &addr, addrlen, &opts); if (fds[0] == -1) goto close_fds; nr_fds = 1; @@ -182,7 +199,7 @@ int *start_reuseport_server(int family, int type, const char *addr_str, goto close_fds; for (; nr_fds < nr_listens; nr_fds++) { - fds[nr_fds] = __start_server(type, (struct sockaddr *)&addr, addrlen, &opts); + fds[nr_fds] = start_server_addr(type, &addr, addrlen, &opts); if (fds[nr_fds] == -1) goto close_fds; } @@ -194,15 +211,6 @@ close_fds: return NULL; } -int start_server_addr(int type, const struct sockaddr_storage *addr, socklen_t len, - const struct network_helper_opts *opts) -{ - if (!opts) - opts = &default_opts; - - return __start_server(type, (struct sockaddr *)addr, len, opts); -} - void free_fds(int *fds, unsigned int nr_close_fds) { if (fds) { @@ -277,33 +285,6 @@ error_close: return -1; } -static int connect_fd_to_addr(int fd, - const struct sockaddr_storage *addr, - socklen_t addrlen, const bool must_fail) -{ - int ret; - - errno = 0; - ret = connect(fd, (const struct sockaddr *)addr, addrlen); - if (must_fail) { - if (!ret) { - log_err("Unexpected success to connect to server"); - return -1; - } - if (errno != EPERM) { - log_err("Unexpected error from connect to server"); - return -1; - } - } else { - if (ret) { - log_err("Failed to connect to server"); - return -1; - } - } - - return 0; -} - int connect_to_addr(int type, const struct sockaddr_storage *addr, socklen_t addrlen, const struct network_helper_opts *opts) { @@ -318,17 +299,17 @@ int connect_to_addr(int type, const struct sockaddr_storage *addr, socklen_t add return -1; } - if (connect_fd_to_addr(fd, addr, addrlen, opts->must_fail)) - goto error_close; + if (connect(fd, (const struct sockaddr *)addr, addrlen)) { + log_err("Failed to connect to server"); + save_errno_close(fd); + return -1; + } return fd; - -error_close: - save_errno_close(fd); - return -1; } -int connect_to_fd_opts(int server_fd, int type, const struct network_helper_opts *opts) +int connect_to_addr_str(int family, int type, const char *addr_str, __u16 port, + const struct network_helper_opts *opts) { struct sockaddr_storage addr; socklen_t addrlen; @@ -336,6 +317,27 @@ int connect_to_fd_opts(int server_fd, int type, const struct network_helper_opts if (!opts) opts = &default_opts; + if (make_sockaddr(family, addr_str, port, &addr, &addrlen)) + return -1; + + return connect_to_addr(type, &addr, addrlen, opts); +} + +int connect_to_fd_opts(int server_fd, const struct network_helper_opts *opts) +{ + struct sockaddr_storage addr; + socklen_t addrlen, optlen; + int type; + + if (!opts) + opts = &default_opts; + + optlen = sizeof(type); + if (getsockopt(server_fd, SOL_SOCKET, SO_TYPE, &type, &optlen)) { + log_err("getsockopt(SOL_TYPE)"); + return -1; + } + addrlen = sizeof(addr); if (getsockname(server_fd, (struct sockaddr *)&addr, &addrlen)) { log_err("Failed to get server addr"); @@ -350,14 +352,8 @@ int connect_to_fd(int server_fd, int timeout_ms) struct network_helper_opts opts = { .timeout_ms = timeout_ms, }; - int type, protocol; socklen_t optlen; - - optlen = sizeof(type); - if (getsockopt(server_fd, SOL_SOCKET, SO_TYPE, &type, &optlen)) { - log_err("getsockopt(SOL_TYPE)"); - return -1; - } + int protocol; optlen = sizeof(protocol); if (getsockopt(server_fd, SOL_SOCKET, SO_PROTOCOL, &protocol, &optlen)) { @@ -366,7 +362,7 @@ int connect_to_fd(int server_fd, int timeout_ms) } opts.proto = protocol; - return connect_to_fd_opts(server_fd, type, &opts); + return connect_to_fd_opts(server_fd, &opts); } int connect_fd_to_fd(int client_fd, int server_fd, int timeout_ms) @@ -382,8 +378,10 @@ int connect_fd_to_fd(int client_fd, int server_fd, int timeout_ms) return -1; } - if (connect_fd_to_addr(client_fd, &addr, len, false)) + if (connect(client_fd, (const struct sockaddr *)&addr, len)) { + log_err("Failed to connect to server"); return -1; + } return 0; } @@ -448,6 +446,52 @@ char *ping_command(int family) return "ping"; } +int remove_netns(const char *name) +{ + char *cmd; + int r; + + r = asprintf(&cmd, "ip netns del %s >/dev/null 2>&1", name); + if (r < 0) { + log_err("Failed to malloc cmd"); + return -1; + } + + r = system(cmd); + free(cmd); + return r; +} + +int make_netns(const char *name) +{ + char *cmd; + int r; + + r = asprintf(&cmd, "ip netns add %s", name); + if (r < 0) { + log_err("Failed to malloc cmd"); + return -1; + } + + r = system(cmd); + free(cmd); + + if (r) + return r; + + r = asprintf(&cmd, "ip -n %s link set lo up", name); + if (r < 0) { + log_err("Failed to malloc cmd for setting up lo"); + remove_netns(name); + return -1; + } + + r = system(cmd); + free(cmd); + + return r; +} + struct nstoken { int orig_netns_fd; }; @@ -676,3 +720,443 @@ int send_recv_data(int lfd, int fd, uint32_t total_bytes) return err; } + +#ifdef TRAFFIC_MONITOR +struct tmonitor_ctx { + pcap_t *pcap; + pcap_dumper_t *dumper; + pthread_t thread; + int wake_fd; + + volatile bool done; + char pkt_fname[PATH_MAX]; + int pcap_fd; +}; + +/* Is this packet captured with a Ethernet protocol type? */ +static bool is_ethernet(const u_char *packet) +{ + u16 arphdr_type; + + memcpy(&arphdr_type, packet + 8, 2); + arphdr_type = ntohs(arphdr_type); + + /* Except the following cases, the protocol type contains the + * Ethernet protocol type for the packet. + * + * https://www.tcpdump.org/linktypes/LINKTYPE_LINUX_SLL2.html + */ + switch (arphdr_type) { + case 770: /* ARPHRD_FRAD */ + case 778: /* ARPHDR_IPGRE */ + case 803: /* ARPHRD_IEEE80211_RADIOTAP */ + printf("Packet captured: arphdr_type=%d\n", arphdr_type); + return false; + } + return true; +} + +static const char * const pkt_types[] = { + "In", + "B", /* Broadcast */ + "M", /* Multicast */ + "C", /* Captured with the promiscuous mode */ + "Out", +}; + +static const char *pkt_type_str(u16 pkt_type) +{ + if (pkt_type < ARRAY_SIZE(pkt_types)) + return pkt_types[pkt_type]; + return "Unknown"; +} + +/* Show the information of the transport layer in the packet */ +static void show_transport(const u_char *packet, u16 len, u32 ifindex, + const char *src_addr, const char *dst_addr, + u16 proto, bool ipv6, u8 pkt_type) +{ + char *ifname, _ifname[IF_NAMESIZE]; + const char *transport_str; + u16 src_port, dst_port; + struct udphdr *udp; + struct tcphdr *tcp; + + ifname = if_indextoname(ifindex, _ifname); + if (!ifname) { + snprintf(_ifname, sizeof(_ifname), "unknown(%d)", ifindex); + ifname = _ifname; + } + + if (proto == IPPROTO_UDP) { + udp = (struct udphdr *)packet; + src_port = ntohs(udp->source); + dst_port = ntohs(udp->dest); + transport_str = "UDP"; + } else if (proto == IPPROTO_TCP) { + tcp = (struct tcphdr *)packet; + src_port = ntohs(tcp->source); + dst_port = ntohs(tcp->dest); + transport_str = "TCP"; + } else if (proto == IPPROTO_ICMP) { + printf("%-7s %-3s IPv4 %s > %s: ICMP, length %d, type %d, code %d\n", + ifname, pkt_type_str(pkt_type), src_addr, dst_addr, len, + packet[0], packet[1]); + return; + } else if (proto == IPPROTO_ICMPV6) { + printf("%-7s %-3s IPv6 %s > %s: ICMPv6, length %d, type %d, code %d\n", + ifname, pkt_type_str(pkt_type), src_addr, dst_addr, len, + packet[0], packet[1]); + return; + } else { + printf("%-7s %-3s %s %s > %s: protocol %d\n", + ifname, pkt_type_str(pkt_type), ipv6 ? "IPv6" : "IPv4", + src_addr, dst_addr, proto); + return; + } + + /* TCP or UDP*/ + + flockfile(stdout); + if (ipv6) + printf("%-7s %-3s IPv6 %s.%d > %s.%d: %s, length %d", + ifname, pkt_type_str(pkt_type), src_addr, src_port, + dst_addr, dst_port, transport_str, len); + else + printf("%-7s %-3s IPv4 %s:%d > %s:%d: %s, length %d", + ifname, pkt_type_str(pkt_type), src_addr, src_port, + dst_addr, dst_port, transport_str, len); + + if (proto == IPPROTO_TCP) { + if (tcp->fin) + printf(", FIN"); + if (tcp->syn) + printf(", SYN"); + if (tcp->rst) + printf(", RST"); + if (tcp->ack) + printf(", ACK"); + } + + printf("\n"); + funlockfile(stdout); +} + +static void show_ipv6_packet(const u_char *packet, u32 ifindex, u8 pkt_type) +{ + char src_buf[INET6_ADDRSTRLEN], dst_buf[INET6_ADDRSTRLEN]; + struct ipv6hdr *pkt = (struct ipv6hdr *)packet; + const char *src, *dst; + u_char proto; + + src = inet_ntop(AF_INET6, &pkt->saddr, src_buf, sizeof(src_buf)); + if (!src) + src = "<invalid>"; + dst = inet_ntop(AF_INET6, &pkt->daddr, dst_buf, sizeof(dst_buf)); + if (!dst) + dst = "<invalid>"; + proto = pkt->nexthdr; + show_transport(packet + sizeof(struct ipv6hdr), + ntohs(pkt->payload_len), + ifindex, src, dst, proto, true, pkt_type); +} + +static void show_ipv4_packet(const u_char *packet, u32 ifindex, u8 pkt_type) +{ + char src_buf[INET_ADDRSTRLEN], dst_buf[INET_ADDRSTRLEN]; + struct iphdr *pkt = (struct iphdr *)packet; + const char *src, *dst; + u_char proto; + + src = inet_ntop(AF_INET, &pkt->saddr, src_buf, sizeof(src_buf)); + if (!src) + src = "<invalid>"; + dst = inet_ntop(AF_INET, &pkt->daddr, dst_buf, sizeof(dst_buf)); + if (!dst) + dst = "<invalid>"; + proto = pkt->protocol; + show_transport(packet + sizeof(struct iphdr), + ntohs(pkt->tot_len), + ifindex, src, dst, proto, false, pkt_type); +} + +static void *traffic_monitor_thread(void *arg) +{ + char *ifname, _ifname[IF_NAMESIZE]; + const u_char *packet, *payload; + struct tmonitor_ctx *ctx = arg; + pcap_dumper_t *dumper = ctx->dumper; + int fd = ctx->pcap_fd, nfds, r; + int wake_fd = ctx->wake_fd; + struct pcap_pkthdr header; + pcap_t *pcap = ctx->pcap; + u32 ifindex; + fd_set fds; + u16 proto; + u8 ptype; + + nfds = (fd > wake_fd ? fd : wake_fd) + 1; + FD_ZERO(&fds); + + while (!ctx->done) { + FD_SET(fd, &fds); + FD_SET(wake_fd, &fds); + r = select(nfds, &fds, NULL, NULL, NULL); + if (!r) + continue; + if (r < 0) { + if (errno == EINTR) + continue; + log_err("Fail to select on pcap fd and wake fd"); + break; + } + + /* This instance of pcap is non-blocking */ + packet = pcap_next(pcap, &header); + if (!packet) + continue; + + /* According to the man page of pcap_dump(), first argument + * is the pcap_dumper_t pointer even it's argument type is + * u_char *. + */ + pcap_dump((u_char *)dumper, &header, packet); + + /* Not sure what other types of packets look like. Here, we + * parse only Ethernet and compatible packets. + */ + if (!is_ethernet(packet)) + continue; + + /* Skip SLL2 header + * https://www.tcpdump.org/linktypes/LINKTYPE_LINUX_SLL2.html + * + * Although the document doesn't mention that, the payload + * doesn't include the Ethernet header. The payload starts + * from the first byte of the network layer header. + */ + payload = packet + 20; + + memcpy(&proto, packet, 2); + proto = ntohs(proto); + memcpy(&ifindex, packet + 4, 4); + ifindex = ntohl(ifindex); + ptype = packet[10]; + + if (proto == ETH_P_IPV6) { + show_ipv6_packet(payload, ifindex, ptype); + } else if (proto == ETH_P_IP) { + show_ipv4_packet(payload, ifindex, ptype); + } else { + ifname = if_indextoname(ifindex, _ifname); + if (!ifname) { + snprintf(_ifname, sizeof(_ifname), "unknown(%d)", ifindex); + ifname = _ifname; + } + + printf("%-7s %-3s Unknown network protocol type 0x%x\n", + ifname, pkt_type_str(ptype), proto); + } + } + + return NULL; +} + +/* Prepare the pcap handle to capture packets. + * + * This pcap is non-blocking and immediate mode is enabled to receive + * captured packets as soon as possible. The snaplen is set to 1024 bytes + * to limit the size of captured content. The format of the link-layer + * header is set to DLT_LINUX_SLL2 to enable handling various link-layer + * technologies. + */ +static pcap_t *traffic_monitor_prepare_pcap(void) +{ + char errbuf[PCAP_ERRBUF_SIZE]; + pcap_t *pcap; + int r; + + /* Listen on all NICs in the namespace */ + pcap = pcap_create("any", errbuf); + if (!pcap) { + log_err("Failed to open pcap: %s", errbuf); + return NULL; + } + /* Limit the size of the packet (first N bytes) */ + r = pcap_set_snaplen(pcap, 1024); + if (r) { + log_err("Failed to set snaplen: %s", pcap_geterr(pcap)); + goto error; + } + /* To receive packets as fast as possible */ + r = pcap_set_immediate_mode(pcap, 1); + if (r) { + log_err("Failed to set immediate mode: %s", pcap_geterr(pcap)); + goto error; + } + r = pcap_setnonblock(pcap, 1, errbuf); + if (r) { + log_err("Failed to set nonblock: %s", errbuf); + goto error; + } + r = pcap_activate(pcap); + if (r) { + log_err("Failed to activate pcap: %s", pcap_geterr(pcap)); + goto error; + } + /* Determine the format of the link-layer header */ + r = pcap_set_datalink(pcap, DLT_LINUX_SLL2); + if (r) { + log_err("Failed to set datalink: %s", pcap_geterr(pcap)); + goto error; + } + + return pcap; +error: + pcap_close(pcap); + return NULL; +} + +static void encode_test_name(char *buf, size_t len, const char *test_name, const char *subtest_name) +{ + char *p; + + if (subtest_name) + snprintf(buf, len, "%s__%s", test_name, subtest_name); + else + snprintf(buf, len, "%s", test_name); + while ((p = strchr(buf, '/'))) + *p = '_'; + while ((p = strchr(buf, ' '))) + *p = '_'; +} + +#define PCAP_DIR "/tmp/tmon_pcap" + +/* Start to monitor the network traffic in the given network namespace. + * + * netns: the name of the network namespace to monitor. If NULL, the + * current network namespace is monitored. + * test_name: the name of the running test. + * subtest_name: the name of the running subtest if there is. It should be + * NULL if it is not a subtest. + * + * This function will start a thread to capture packets going through NICs + * in the give network namespace. + */ +struct tmonitor_ctx *traffic_monitor_start(const char *netns, const char *test_name, + const char *subtest_name) +{ + struct nstoken *nstoken = NULL; + struct tmonitor_ctx *ctx; + char test_name_buf[64]; + static int tmon_seq; + int r; + + if (netns) { + nstoken = open_netns(netns); + if (!nstoken) + return NULL; + } + ctx = malloc(sizeof(*ctx)); + if (!ctx) { + log_err("Failed to malloc ctx"); + goto fail_ctx; + } + memset(ctx, 0, sizeof(*ctx)); + + encode_test_name(test_name_buf, sizeof(test_name_buf), test_name, subtest_name); + snprintf(ctx->pkt_fname, sizeof(ctx->pkt_fname), + PCAP_DIR "/packets-%d-%d-%s-%s.log", getpid(), tmon_seq++, + test_name_buf, netns ? netns : "unknown"); + + r = mkdir(PCAP_DIR, 0755); + if (r && errno != EEXIST) { + log_err("Failed to create " PCAP_DIR); + goto fail_pcap; + } + + ctx->pcap = traffic_monitor_prepare_pcap(); + if (!ctx->pcap) + goto fail_pcap; + ctx->pcap_fd = pcap_get_selectable_fd(ctx->pcap); + if (ctx->pcap_fd < 0) { + log_err("Failed to get pcap fd"); + goto fail_dumper; + } + + /* Create a packet file */ + ctx->dumper = pcap_dump_open(ctx->pcap, ctx->pkt_fname); + if (!ctx->dumper) { + log_err("Failed to open pcap dump: %s", ctx->pkt_fname); + goto fail_dumper; + } + + /* Create an eventfd to wake up the monitor thread */ + ctx->wake_fd = eventfd(0, 0); + if (ctx->wake_fd < 0) { + log_err("Failed to create eventfd"); + goto fail_eventfd; + } + + r = pthread_create(&ctx->thread, NULL, traffic_monitor_thread, ctx); + if (r) { + log_err("Failed to create thread"); + goto fail; + } + + close_netns(nstoken); + + return ctx; + +fail: + close(ctx->wake_fd); + +fail_eventfd: + pcap_dump_close(ctx->dumper); + unlink(ctx->pkt_fname); + +fail_dumper: + pcap_close(ctx->pcap); + +fail_pcap: + free(ctx); + +fail_ctx: + close_netns(nstoken); + + return NULL; +} + +static void traffic_monitor_release(struct tmonitor_ctx *ctx) +{ + pcap_close(ctx->pcap); + pcap_dump_close(ctx->dumper); + + close(ctx->wake_fd); + + free(ctx); +} + +/* Stop the network traffic monitor. + * + * ctx: the context returned by traffic_monitor_start() + */ +void traffic_monitor_stop(struct tmonitor_ctx *ctx) +{ + __u64 w = 1; + + if (!ctx) + return; + + /* Stop the monitor thread */ + ctx->done = true; + /* Wake up the background thread. */ + write(ctx->wake_fd, &w, sizeof(w)); + pthread_join(ctx->thread, NULL); + + printf("Packet file: %s\n", strrchr(ctx->pkt_fname, '/') + 1); + + traffic_monitor_release(ctx); +} +#endif /* TRAFFIC_MONITOR */ |