cregit-Linux how code gets into the kernel

Release 4.14 samples/bpf/xdp_monitor_user.c

Directory: samples/bpf
/* Copyright(c) 2017 Jesper Dangaard Brouer, Red Hat, Inc.
 */

static const char *__doc__=
 "XDP monitor tool, based on tracepoints\n"
;


static const char *__doc_err_only__=
 " NOTICE: Only tracking XDP redirect errors\n"
 "         Enable TX success stats via '--stats'\n"
 "         (which comes with a per packet processing overhead)\n"
;

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include <ctype.h>
#include <unistd.h>
#include <locale.h>

#include <getopt.h>
#include <net/if.h>
#include <time.h>

#include "libbpf.h"
#include "bpf_load.h"
#include "bpf_util.h"


static int verbose = 1;

static bool debug = false;


static const struct option long_options[] = {
	{"help",	no_argument,		NULL, 'h' },
	{"debug",	no_argument,		NULL, 'D' },
	{"stats",	no_argument,		NULL, 'S' },
	{"sec", 	required_argument,	NULL, 's' },
	{0, 0, NULL,  0 }
};


static void usage(char *argv[]) { int i; printf("\nDOCUMENTATION:\n%s\n", __doc__); printf("\n"); printf(" Usage: %s (options-see-below)\n", argv[0]); printf(" Listing options:\n"); for (i = 0; long_options[i].name != 0; i++) { printf(" --%-15s", long_options[i].name); if (long_options[i].flag != NULL) printf(" flag (internal value:%d)", *long_options[i].flag); else printf("(internal short-option: -%c)", long_options[i].val); printf("\n"); } printf("\n"); }

Contributors

PersonTokensPropCommitsCommitProp
Jesper Dangaard Brouer120100.00%1100.00%
Total120100.00%1100.00%

#define NANOSEC_PER_SEC 1000000000 /* 10^9 */
__u64 gettime(void) { struct timespec t; int res; res = clock_gettime(CLOCK_MONOTONIC, &t); if (res < 0) { fprintf(stderr, "Error with gettimeofday! (%i)\n", res); exit(EXIT_FAILURE); } return (__u64) t.tv_sec * NANOSEC_PER_SEC + t.tv_nsec; }

Contributors

PersonTokensPropCommitsCommitProp
Jesper Dangaard Brouer60100.00%1100.00%
Total60100.00%1100.00%

enum { REDIR_SUCCESS = 0, REDIR_ERROR = 1, }; #define REDIR_RES_MAX 2 static const char *redir_names[REDIR_RES_MAX] = { [REDIR_SUCCESS] = "Success", [REDIR_ERROR] = "Error", };
static const char *err2str(int err) { if (err < REDIR_RES_MAX) return redir_names[err]; return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
Jesper Dangaard Brouer26100.00%1100.00%
Total26100.00%1100.00%

struct record { __u64 counter; __u64 timestamp; }; struct stats_record { struct record xdp_redir[REDIR_RES_MAX]; };
static void stats_print_headers(bool err_only) { if (err_only) printf("\n%s\n", __doc_err_only__); printf("%-14s %-10s %-18s %-9s\n", "XDP_REDIRECT", "pps ", "pps-human-readable", "measure-period"); }

Contributors

PersonTokensPropCommitsCommitProp
Jesper Dangaard Brouer33100.00%1100.00%
Total33100.00%1100.00%


static void stats_print(struct stats_record *rec, struct stats_record *prev, bool err_only) { int i = 0; if (err_only) i = REDIR_ERROR; for (; i < REDIR_RES_MAX; i++) { struct record *r = &rec->xdp_redir[i]; struct record *p = &prev->xdp_redir[i]; __u64 period = 0; __u64 packets = 0; double pps = 0; double period_ = 0; if (p->timestamp) { packets = r->counter - p->counter; period = r->timestamp - p->timestamp; if (period > 0) { period_ = ((double) period / NANOSEC_PER_SEC); pps = packets / period_; } } printf("%-14s %-10.0f %'-18.0f %f\n", err2str(i), pps, pps, period_); } }

Contributors

PersonTokensPropCommitsCommitProp
Jesper Dangaard Brouer159100.00%1100.00%
Total159100.00%1100.00%


static __u64 get_key32_value64_percpu(int fd, __u32 key) { /* For percpu maps, userspace gets a value per possible CPU */ unsigned int nr_cpus = bpf_num_possible_cpus(); __u64 values[nr_cpus]; __u64 sum = 0; int i; if ((bpf_map_lookup_elem(fd, &key, values)) != 0) { fprintf(stderr, "ERR: bpf_map_lookup_elem failed key:0x%X\n", key); return 0; } /* Sum values from each CPU */ for (i = 0; i < nr_cpus; i++) { sum += values[i]; } return sum; }

Contributors

PersonTokensPropCommitsCommitProp
Jesper Dangaard Brouer90100.00%1100.00%
Total90100.00%1100.00%


static bool stats_collect(int fd, struct stats_record *rec) { int i; /* TODO: Detect if someone unloaded the perf event_fd's, as * this can happen by someone running perf-record -e */ for (i = 0; i < REDIR_RES_MAX; i++) { rec->xdp_redir[i].timestamp = gettime(); rec->xdp_redir[i].counter = get_key32_value64_percpu(fd, i); } return true; }

Contributors

PersonTokensPropCommitsCommitProp
Jesper Dangaard Brouer64100.00%1100.00%
Total64100.00%1100.00%


static void stats_poll(int interval, bool err_only) { struct stats_record rec, prev; int map_fd; memset(&rec, 0, sizeof(rec)); /* Trick to pretty printf with thousands separators use %' */ setlocale(LC_NUMERIC, "en_US"); /* Header */ if (verbose) printf("\n%s", __doc__); /* TODO Need more advanced stats on error types */ if (verbose) printf(" - Stats map: %s\n", map_data[0].name); map_fd = map_data[0].fd; stats_print_headers(err_only); fflush(stdout); while (1) { memcpy(&prev, &rec, sizeof(rec)); stats_collect(map_fd, &rec); stats_print(&rec, &prev, err_only); fflush(stdout); sleep(interval); } }

Contributors

PersonTokensPropCommitsCommitProp
Jesper Dangaard Brouer139100.00%1100.00%
Total139100.00%1100.00%


void print_bpf_prog_info(void) { int i; /* Prog info */ printf("Loaded BPF prog have %d bpf program(s)\n", prog_cnt); for (i = 0; i < prog_cnt; i++) { printf(" - prog_fd[%d] = fd(%d)\n", i, prog_fd[i]); } /* Maps info */ printf("Loaded BPF prog have %d map(s)\n", map_data_count); for (i = 0; i < map_data_count; i++) { char *name = map_data[i].name; int fd = map_data[i].fd; printf(" - map_data[%d] = fd(%d) name:%s\n", i, fd, name); } /* Event info */ printf("Searching for (max:%d) event file descriptor(s)\n", prog_cnt); for (i = 0; i < prog_cnt; i++) { if (event_fd[i] != -1) printf(" - event_fd[%d] = fd(%d)\n", i, event_fd[i]); } }

Contributors

PersonTokensPropCommitsCommitProp
Jesper Dangaard Brouer145100.00%1100.00%
Total145100.00%1100.00%


int main(int argc, char **argv) { int longindex = 0, opt; int ret = EXIT_SUCCESS; char bpf_obj_file[256]; /* Default settings: */ bool errors_only = true; int interval = 2; snprintf(bpf_obj_file, sizeof(bpf_obj_file), "%s_kern.o", argv[0]); /* Parse commands line args */ while ((opt = getopt_long(argc, argv, "h", long_options, &longindex)) != -1) { switch (opt) { case 'D': debug = true; break; case 'S': errors_only = false; break; case 's': interval = atoi(optarg); break; case 'h': default: usage(argv); return EXIT_FAILURE; } } if (load_bpf_file(bpf_obj_file)) { printf("ERROR - bpf_log_buf: %s", bpf_log_buf); return 1; } if (!prog_fd[0]) { printf("ERROR - load_bpf_file: %s\n", strerror(errno)); return 1; } if (debug) { print_bpf_prog_info(); } /* Unload/stop tracepoint event by closing fd's */ if (errors_only) { /* The prog_fd[i] and event_fd[i] depend on the * order the functions was defined in _kern.c */ close(event_fd[2]); /* tracepoint/xdp/xdp_redirect */ close(prog_fd[2]); /* func: trace_xdp_redirect */ close(event_fd[3]); /* tracepoint/xdp/xdp_redirect_map */ close(prog_fd[3]); /* func: trace_xdp_redirect_map */ } stats_poll(interval, errors_only); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Jesper Dangaard Brouer235100.00%1100.00%
Total235100.00%1100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Jesper Dangaard Brouer1272100.00%1100.00%
Total1272100.00%1100.00%
Directory: samples/bpf
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.