[RFC,v2,5/5] Add sample for adding simple drop program to link

Message ID	1460090930-11219-5-git-send-email-bblanco@plumgrid.com
State	RFC, archived
Delegated to:	David Miller
Headers	show Return-Path: <netdev-owner@vger.kernel.org> From: Brenden Blanco <bblanco@plumgrid.com> To: davem@davemloft.net Cc: Brenden Blanco <bblanco@plumgrid.com>, netdev@vger.kernel.org, tom@herbertland.com, alexei.starovoitov@gmail.com, ogerlitz@mellanox.com, daniel@iogearbox.net, brouer@redhat.com, eric.dumazet@gmail.com, ecree@solarflare.com, john.fastabend@gmail.com, tgraf@suug.ch, johannes@sipsolutions.net, eranlinuxmellanox@gmail.com, lorenzo@google.com Subject: [RFC PATCH v2 5/5] Add sample for adding simple drop program to link Date: Thu, 7 Apr 2016 21:48:50 -0700 Message-Id: <1460090930-11219-5-git-send-email-bblanco@plumgrid.com> In-Reply-To: <1460090930-11219-1-git-send-email-bblanco@plumgrid.com> References: <1460090930-11219-1-git-send-email-bblanco@plumgrid.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk

diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 9959771..19bb926 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -20,6 +20,7 @@ hostprogs-y += offwaketime hostprogs-y += spintest hostprogs-y += map_perf_test hostprogs-y += test_overhead +hostprogs-y += netdrvx1 test_verifier-objs := test_verifier.o libbpf.o test_maps-objs := test_maps.o libbpf.o @@ -40,6 +41,7 @@ offwaketime-objs := bpf_load.o libbpf.o offwaketime_user.o spintest-objs := bpf_load.o libbpf.o spintest_user.o map_perf_test-objs := bpf_load.o libbpf.o map_perf_test_user.o test_overhead-objs := bpf_load.o libbpf.o test_overhead_user.o +netdrvx1-objs := bpf_load.o libbpf.o netdrvx1_user.o # Tell kbuild to always build the programs always := $(hostprogs-y) @@ -60,6 +62,7 @@ always += spintest_kern.o always += map_perf_test_kern.o always += test_overhead_tp_kern.o always += test_overhead_kprobe_kern.o +always += netdrvx1_kern.o HOSTCFLAGS += -I$(objtree)/usr/include @@ -80,6 +83,7 @@ HOSTLOADLIBES_offwaketime += -lelf HOSTLOADLIBES_spintest += -lelf HOSTLOADLIBES_map_perf_test += -lelf -lrt HOSTLOADLIBES_test_overhead += -lelf -lrt +HOSTLOADLIBES_netdrvx1 += -lelf # point this to your LLVM backend with bpf support LLC=$(srctree)/tools/bpf/llvm/bld/Debug+Asserts/bin/llc diff --git a/samples/bpf/bpf_load.c b/samples/bpf/bpf_load.c index 022af71..c7b2245 100644 --- a/samples/bpf/bpf_load.c +++ b/samples/bpf/bpf_load.c @@ -50,6 +50,7 @@ static int load_and_attach(const char *event, struct bpf_insn *prog, int size) bool is_kprobe = strncmp(event, "kprobe/", 7) == 0; bool is_kretprobe = strncmp(event, "kretprobe/", 10) == 0; bool is_tracepoint = strncmp(event, "tracepoint/", 11) == 0; + bool is_phys_dev = strncmp(event, "phys_dev", 8) == 0; enum bpf_prog_type prog_type; char buf[256]; int fd, efd, err, id; @@ -66,6 +67,8 @@ static int load_and_attach(const char *event, struct bpf_insn *prog, int size) prog_type = BPF_PROG_TYPE_KPROBE; } else if (is_tracepoint) { prog_type = BPF_PROG_TYPE_TRACEPOINT; + } else if (is_phys_dev) { + prog_type = BPF_PROG_TYPE_PHYS_DEV; } else { printf("Unknown event '%s'\n", event); return -1; @@ -79,6 +82,9 @@ static int load_and_attach(const char *event, struct bpf_insn *prog, int size) prog_fd[prog_cnt++] = fd; + if (is_phys_dev) + return 0; + if (is_socket) { event += 6; if (*event != '/') @@ -319,6 +325,7 @@ int load_bpf_file(char *path) if (memcmp(shname_prog, "kprobe/", 7) == 0 || memcmp(shname_prog, "kretprobe/", 10) == 0 || memcmp(shname_prog, "tracepoint/", 11) == 0 || + memcmp(shname_prog, "phys_dev", 8) == 0 || memcmp(shname_prog, "socket", 6) == 0) load_and_attach(shname_prog, insns, data_prog->d_size); } @@ -336,6 +343,7 @@ int load_bpf_file(char *path) if (memcmp(shname, "kprobe/", 7) == 0 || memcmp(shname, "kretprobe/", 10) == 0 || memcmp(shname, "tracepoint/", 11) == 0 || + memcmp(shname, "phys_dev", 8) == 0 || memcmp(shname, "socket", 6) == 0) load_and_attach(shname, data->d_buf, data->d_size); } diff --git a/samples/bpf/netdrvx1_kern.c b/samples/bpf/netdrvx1_kern.c new file mode 100644 index 0000000..849802d --- /dev/null +++ b/samples/bpf/netdrvx1_kern.c @@ -0,0 +1,26 @@ +#include <uapi/linux/bpf.h> +#include <uapi/linux/if_ether.h> +#include <uapi/linux/if_packet.h> +#include <uapi/linux/ip.h> +#include "bpf_helpers.h" + +struct bpf_map_def SEC("maps") dropcnt = { + .type = BPF_MAP_TYPE_PERCPU_ARRAY, + .key_size = sizeof(u32), + .value_size = sizeof(long), + .max_entries = 256, +}; + +SEC("phys_dev1") +int bpf_prog1(struct bpf_phys_dev_md *ctx) +{ + int index = load_byte(ctx, ETH_HLEN + offsetof(struct iphdr, protocol)); + long *value; + + value = bpf_map_lookup_elem(&dropcnt, &index); + if (value) + *value += 1; + + return BPF_PHYS_DEV_DROP; +} +char _license[] SEC("license") = "GPL"; diff --git a/samples/bpf/netdrvx1_user.c b/samples/bpf/netdrvx1_user.c new file mode 100644 index 0000000..9e6ec9a --- /dev/null +++ b/samples/bpf/netdrvx1_user.c @@ -0,0 +1,155 @@ +#include <linux/bpf.h> +#include <linux/netlink.h> +#include <linux/rtnetlink.h> +#include <assert.h> +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/socket.h> +#include <unistd.h> +#include "bpf_load.h" +#include "libbpf.h" + +static int set_link_bpf_fd(int ifindex, int fd) +{ + struct sockaddr_nl sa; + int sock, seq = 0, len, ret = -1; + char buf[4096]; + struct rtattr *rta; + struct { + struct nlmsghdr nh; + struct ifinfomsg ifinfo; + char attrbuf[64]; + } req; + struct nlmsghdr *nh; + struct nlmsgerr *err; + + memset(&sa, 0, sizeof(sa)); + sa.nl_family = AF_NETLINK; + + sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); + if (sock < 0) { + printf("open netlink socket: %s\n", strerror(errno)); + return -1; + } + + if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) { + printf("bind to netlink: %s\n", strerror(errno)); + goto cleanup; + } + + memset(&req, 0, sizeof(req)); + req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)); + req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK; + req.nh.nlmsg_type = RTM_SETLINK; + req.nh.nlmsg_pid = 0; + req.nh.nlmsg_seq = ++seq; + req.ifinfo.ifi_family = AF_UNSPEC; + req.ifinfo.ifi_index = ifindex; + rta = (struct rtattr *)(((char *) &req) + + NLMSG_ALIGN(req.nh.nlmsg_len)); + rta->rta_type = 42/*IFLA_BPF_FD*/; + rta->rta_len = RTA_LENGTH(sizeof(unsigned int)); + req.nh.nlmsg_len = NLMSG_ALIGN(req.nh.nlmsg_len) + + RTA_LENGTH(sizeof(fd)); + memcpy(RTA_DATA(rta), &fd, sizeof(fd)); + if (send(sock, &req, req.nh.nlmsg_len, 0) < 0) { + printf("send to netlink: %s\n", strerror(errno)); + goto cleanup; + } + + len = recv(sock, buf, sizeof(buf), 0); + if (len < 0) { + printf("recv from netlink: %s\n", strerror(errno)); + goto cleanup; + } + + for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, len); + nh = NLMSG_NEXT(nh, len)) { + if (nh->nlmsg_pid != getpid()) { + printf("Wrong pid %d, expected %d\n", + nh->nlmsg_pid, getpid()); + goto cleanup; + } + if (nh->nlmsg_seq != seq) { + printf("Wrong seq %d, expected %d\n", + nh->nlmsg_seq, seq); + goto cleanup; + } + switch (nh->nlmsg_type) { + case NLMSG_ERROR: + err = (struct nlmsgerr *)NLMSG_DATA(nh); + if (!err->error) + continue; + printf("nlmsg error %s\n", strerror(-err->error)); + goto cleanup; + case NLMSG_DONE: + break; + } + } + + ret = 0; + +cleanup: + close(sock); + return ret; +} + +/* simple per-protocol drop counter + */ +static void poll_stats(int secs) +{ + unsigned int nr_cpus = sysconf(_SC_NPROCESSORS_CONF); + __u64 values[nr_cpus]; + __u32 key; + int i; + + sleep(secs); + + for (key = 0; key < 256; key++) { + __u64 sum = 0; + + assert(bpf_lookup_elem(map_fd[0], &key, values) == 0); + for (i = 0; i < nr_cpus; i++) + sum += values[i]; + if (sum) + printf("proto %u: %10llu drops/s\n", key, sum/secs); + } +} + +int main(int ac, char **argv) +{ + char filename[256]; + int ifindex; + + snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + + if (ac != 2) { + printf("usage: %s IFINDEX\n", argv[0]); + return 1; + } + + ifindex = strtoul(argv[1], NULL, 0); + + if (load_bpf_file(filename)) { + printf("%s", bpf_log_buf); + return 1; + } + + if (!prog_fd[0]) { + printf("load_bpf_file: %s\n", strerror(errno)); + return 1; + } + + if (set_link_bpf_fd(ifindex, prog_fd[0]) < 0) { + printf("link set bpf fd failed\n"); + return 1; + } + + poll_stats(5); + + set_link_bpf_fd(ifindex, -1); + + return 0; +}

[RFC,v2,5/5] Add sample for adding simple drop program to link

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