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xdpdump.c
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/* SPDX-License-Identifier: GPL-2.0 */
/*****************************************************************************
* Include files
*****************************************************************************/
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <bpf/bpf.h>
#include <bpf/btf.h>
#include <bpf/libbpf.h>
#include <linux/err.h>
#include <linux/ethtool.h>
#include <linux/perf_event.h>
#include <linux/sockios.h>
#include <net/if.h>
#define PCAP_DONT_INCLUDE_PCAP_BPF_H
#include <pcap/dlt.h>
#include <pcap/pcap.h>
#include <sys/ioctl.h>
#include <sys/resource.h>
#include <sys/sysinfo.h>
#include <sys/utsname.h>
#include <xdp/prog_dispatcher.h>
#include "logging.h"
#include "params.h"
#include "util.h"
#include "xdpdump.h"
#include "xpcapng.h"
#include "compat.h"
/*****************************************************************************
* Local definitions and global variables
*****************************************************************************/
#define PROG_NAME "xdpdump"
#define DEFAULT_SNAP_LEN 262144
#ifndef ENOTSUPP
#define ENOTSUPP 524 /* Operation is not supported */
#endif
#define RX_FLAG_FENTRY (1<<0)
#define RX_FLAG_FEXIT (1<<1)
struct flag_val rx_capture_flags[] = {
{"entry", RX_FLAG_FENTRY},
{"exit", RX_FLAG_FEXIT},
{}
};
struct enum_val xdp_modes[] = {
{"native", XDP_MODE_NATIVE},
{"skb", XDP_MODE_SKB},
{"hw", XDP_MODE_HW},
{"unspecified", XDP_MODE_UNSPEC},
{NULL, 0}
};
static const struct dumpopt {
bool hex_dump;
bool list_interfaces;
bool load_xdp;
bool promiscuous;
bool use_pcap;
struct iface iface;
uint32_t perf_wakeup;
uint32_t snaplen;
char *pcap_file;
char *program_names;
unsigned int load_xdp_mode;
unsigned int rx_capture;
} defaults_dumpopt = {
.hex_dump = false,
.list_interfaces = false,
.load_xdp = false,
.promiscuous = false,
.use_pcap = false,
.snaplen = DEFAULT_SNAP_LEN,
.load_xdp_mode = XDP_MODE_NATIVE,
.rx_capture = RX_FLAG_FENTRY,
};
struct dumpopt cfg_dumpopt;
static struct prog_option xdpdump_options[] = {
DEFINE_OPTION("rx-capture", OPT_FLAGS, struct dumpopt, rx_capture,
.metavar = "<mode>",
.typearg = rx_capture_flags,
.help = "Capture point for the rx direction"),
DEFINE_OPTION("list-interfaces", OPT_BOOL, struct dumpopt,
list_interfaces,
.short_opt = 'D',
.help = "Print the list of available interfaces"),
DEFINE_OPTION("load-xdp-mode", OPT_ENUM, struct dumpopt, load_xdp_mode,
.typearg = xdp_modes,
.metavar = "<mode>",
.help = "Mode used for --load-xdp-mode, default native"),
DEFINE_OPTION("load-xdp-program", OPT_BOOL, struct dumpopt, load_xdp,
.help = "Load XDP trace program if no XDP program is loaded"),
DEFINE_OPTION("interface", OPT_IFNAME, struct dumpopt, iface,
.short_opt = 'i',
.metavar = "<ifname>",
.help = "Name of interface to capture on"),
#ifdef HAVE_LIBBPF_PERF_BUFFER__CONSUME
DEFINE_OPTION("perf-wakeup", OPT_U32, struct dumpopt, perf_wakeup,
.metavar = "<events>",
.help = "Wake up xdpdump every <events> packets"),
#endif
DEFINE_OPTION("program-names", OPT_STRING, struct dumpopt,
program_names,
.short_opt = 'p',
.metavar = "<prog>",
.help = "Specific program to attach to"),
DEFINE_OPTION("promiscuous-mode", OPT_BOOL, struct dumpopt,
promiscuous,
.short_opt = 'P',
.help = "Open interface in promiscuous mode"),
DEFINE_OPTION("snapshot-length", OPT_U32, struct dumpopt, snaplen,
.short_opt = 's',
.metavar = "<snaplen>",
.help = "Minimum bytes of packet to capture"),
DEFINE_OPTION("use-pcap", OPT_BOOL, struct dumpopt, use_pcap,
.help = "Use legacy pcap format for XDP traces"),
DEFINE_OPTION("write", OPT_STRING, struct dumpopt, pcap_file,
.short_opt = 'w',
.metavar = "<file>",
.help = "Write raw packets to pcap file"),
DEFINE_OPTION("hex", OPT_BOOL, struct dumpopt, hex_dump,
.short_opt = 'x',
.help = "Print the full packet in hex"),
END_OPTIONS
};
#define MAX_LOADED_XDP_PROGRAMS (MAX_DISPATCHER_ACTIONS + 1)
struct capture_programs {
/* Contains a list of programs to capture on, with the respective
* program names. The order MUST be the same as the loaded order!
*/
unsigned int nr_of_progs;
struct prog_info {
struct xdp_program *prog;
const char *func;
unsigned int rx_capture;
/* Fields used by the actual loader. */
bool attached;
int perf_map_fd;
struct bpf_object *prog_obj;
struct bpf_link *fentry_link;
struct bpf_link *fexit_link;
} progs[MAX_LOADED_XDP_PROGRAMS];
};
struct perf_handler_ctx {
uint64_t missed_events;
uint64_t last_missed_events;
uint64_t captured_packets;
uint64_t epoch_delta;
uint64_t packet_id;
uint64_t cpu_packet_id[MAX_CPUS];
struct dumpopt *cfg;
struct capture_programs *xdp_progs;
pcap_t *pcap;
pcap_dumper_t *pcap_dumper;
struct xpcapng_dumper *pcapng_dumper;
};
bool exit_xdpdump;
pcap_t *exit_pcap;
/*****************************************************************************
* get_if_speed()
*****************************************************************************/
static uint64_t get_if_speed(struct iface *iface)
{
#define MAX_MODE_MASKS 10
int fd;
struct ifreq ifr;
struct {
struct ethtool_link_settings req;
uint32_t modes[3 * MAX_MODE_MASKS];
} ereq;
if (iface == NULL)
return 0;
/* Open socket, and initialize structures. */
fd = socket(AF_INET, SOCK_DGRAM, 0);
if (fd < 0)
return 0;
memset(&ereq, 0, sizeof(ereq));
ereq.req.cmd = ETHTOOL_GLINKSETTINGS;
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.ifr_name, iface->ifname, sizeof(ifr.ifr_name) - 1);
ifr.ifr_data = (void *)&ereq;
/* First query the kernel to see how many masks we need to ask for. */
if (ioctl(fd, SIOCETHTOOL, &ifr) != 0)
goto error_exit;
if (ereq.req.link_mode_masks_nwords >= 0 ||
ereq.req.link_mode_masks_nwords < -MAX_MODE_MASKS ||
ereq.req.cmd != ETHTOOL_GLINKSETTINGS)
goto error_exit;
/* Now ask for the data set, and extract the speed in bps. */
ereq.req.link_mode_masks_nwords = -ereq.req.link_mode_masks_nwords;
if (ioctl(fd, SIOCETHTOOL, &ifr) != 0)
goto error_exit;
/* If speed is unknown return 0. */
if (ereq.req.speed == -1U)
ereq.req.speed = 0;
close(fd);
return ereq.req.speed * 1000000ULL;
error_exit:
close(fd);
return 0;
}
/*****************************************************************************
* get_if_drv_info()
*****************************************************************************/
static char *get_if_drv_info(struct iface *iface, char *buffer, size_t len)
{
int fd;
char *r_buffer = NULL;
struct ifreq ifr;
struct ethtool_drvinfo info;
if (iface == NULL || buffer == NULL || len == 0)
return NULL;
fd = socket(AF_INET, SOCK_DGRAM, 0);
if (fd < 0)
return NULL;
memset(&info, 0, sizeof(info));
info.cmd = ETHTOOL_GDRVINFO;
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.ifr_name, iface->ifname, sizeof(ifr.ifr_name) - 1);
ifr.ifr_data = (void *)&info;
if (ioctl(fd, SIOCETHTOOL, &ifr) != 0)
goto exit;
if (try_snprintf(buffer, len,
"driver: \"%s\", version: \"%s\", "
"fw-version: \"%s\", rom-version: \"%s\", "
"bus-info: \"%s\"",
info.driver, info.version, info.fw_version,
info.erom_version, info.bus_info))
goto exit;
r_buffer = buffer;
exit:
close(fd);
return r_buffer;
}
/*****************************************************************************
* set_if_promiscuous_mode()
*****************************************************************************/
static int set_if_promiscuous_mode(struct iface *iface, bool enable,
bool *did_enable)
{
int fd;
int rc = 0;
struct ifreq ifr;
if (iface == NULL)
return -EINVAL;
fd = socket(AF_INET, SOCK_DGRAM, 0);
if (fd < 0)
return -errno;
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.ifr_name, iface->ifname, sizeof(ifr.ifr_name) - 1);
if (ioctl(fd, SIOCGIFFLAGS, &ifr) != 0) {
pr_debug("DBG: Failed getting promiscuous mode: %s\n",
strerror(errno));
rc = -errno;
goto exit;
}
if (((ifr.ifr_flags & IFF_PROMISC) && enable) ||
(!(ifr.ifr_flags & IFF_PROMISC) && !enable)) {
pr_debug("DBG: Promiscuous mode already %s!\n",
enable ? "on" : "off");
goto exit;
}
if (enable)
ifr.ifr_flags |= IFF_PROMISC;
else
ifr.ifr_flags &= ~IFF_PROMISC;
if (ioctl(fd, SIOCSIFFLAGS, &ifr) != 0) {
pr_debug("DBG: Failed setting promiscuous mode %s: %s\n",
enable ? "on" : "off", strerror(errno));
rc = -errno;
goto exit;
}
if (did_enable) {
if (enable)
*did_enable = true;
else
*did_enable = false;
}
exit:
close(fd);
return rc;
}
/*****************************************************************************
* get_xdp_return_string()
*****************************************************************************/
static const char *get_xdp_action_string(enum xdp_action act)
{
switch (act) {
case XDP_ABORTED:
return "[ABORTED]";
case XDP_DROP:
return "[DROP]";
case XDP_PASS:
return "[PASS]";
case XDP_TX:
return "[TX]";
case XDP_REDIRECT:
return "[REDIRECT]";
}
return "[*unknown*]";
}
/*****************************************************************************
* get_capture_mode_string()
*****************************************************************************/
static const char *get_capture_mode_string(unsigned int mode)
{
switch(mode) {
case RX_FLAG_FENTRY:
return "entry";
case RX_FLAG_FEXIT:
return "exit";
case RX_FLAG_FENTRY | RX_FLAG_FEXIT:
return "entry/exit";
}
return "unknown";
}
/*****************************************************************************
* snprinth()
*****************************************************************************/
#define SNPRINTH_MIN_BUFFER_SIZE sizeof("0xffff: 00 11 22 33 44 55 66 77 88" \
" 99 aa bb cc dd ee ff " \
"................0")
static int snprinth(char *str, size_t size,
const uint8_t *buffer, size_t buffer_size, size_t offset)
{
int i;
int pre_skip;
int post_skip;
size_t zero_offset;
if (str == NULL || size < SNPRINTH_MIN_BUFFER_SIZE ||
buffer == NULL || offset >= buffer_size || buffer_size > 0xffff)
return -EINVAL;
zero_offset = offset & ~0xf;
pre_skip = offset & 0xf;
post_skip = (zero_offset + 0xf) < buffer_size ? \
0 : 16 - (buffer_size - zero_offset);
/* Print offset */
snprintf(str, size, "0x%04zx: ", offset & 0xfff0);
str += 9;
/* Print hex values */
if (pre_skip) {
memset(str, ' ', pre_skip * 3);
str[pre_skip * 3] = 0;
}
for (i = pre_skip; i < 16 - post_skip; i++) {
snprintf(str + (i * 3), 5, "%02x ",
buffer[zero_offset + i]);
}
if (post_skip) {
memset(str + (i * 3), ' ', post_skip * 3);
str[(i * 3) + (post_skip * 3)] = 0;
}
/* Print printable chars */
str += 16 * 3;
*str++ = ' ';
if (pre_skip) {
memset(str, ' ', pre_skip);
str[pre_skip] = 0;
}
for (i = pre_skip; i < 16 - post_skip; i++)
str[i] = isprint(buffer[zero_offset + i]) ? \
buffer[zero_offset + i]: '.';
str[i] = 0;
return 0;
}
/*****************************************************************************
* handle_perf_event()
*****************************************************************************/
static enum bpf_perf_event_ret handle_perf_event(void *private_data,
int cpu,
struct perf_event_header *event)
{
uint64_t ts;
bool fexit;
unsigned int if_idx, prog_idx;
const char *xdp_func;
struct perf_handler_ctx *ctx = private_data;
struct perf_sample_event *e = container_of(event,
struct perf_sample_event,
header);
struct perf_lost_event *lost = container_of(event,
struct perf_lost_event,
header);
switch(e->header.type) {
case PERF_RECORD_SAMPLE:
if (cpu >= MAX_CPUS ||
e->header.size < sizeof(struct perf_sample_event) ||
e->size < (sizeof(struct pkt_trace_metadata) + e->metadata.cap_len) ||
e->metadata.prog_index >= ctx->xdp_progs->nr_of_progs)
return LIBBPF_PERF_EVENT_CONT;
fexit = e->metadata.flags & MDF_DIRECTION_FEXIT;
prog_idx = e->metadata.prog_index;
if_idx = prog_idx * 2 + (fexit ? 1 : 0);
xdp_func = ctx->xdp_progs->progs[prog_idx].func;
if (prog_idx == 0 &&
(!fexit ||
ctx->xdp_progs->progs[prog_idx].rx_capture == RX_FLAG_FEXIT))
ctx->cpu_packet_id[cpu] = ++ctx->packet_id;
ts = e->time + ctx->epoch_delta;
if (ctx->pcapng_dumper) {
struct xpcapng_epb_options_s options = {};
int64_t action = e->metadata.action;
uint32_t queue = e->metadata.rx_queue;
options.flags = PCAPNG_EPB_FLAG_INBOUND;
options.dropcount = ctx->last_missed_events;
options.packetid = &ctx->cpu_packet_id[cpu];
options.queue = &queue;
options.xdp_verdict = fexit ? &action : NULL;
xpcapng_dump_enhanced_pkt(ctx->pcapng_dumper,
if_idx,
e->packet,
e->metadata.pkt_len,
min(e->metadata.cap_len,
ctx->cfg->snaplen),
ts,
&options);
ctx->last_missed_events = 0;
if (ctx->cfg->pcap_file[0] == '-' &&
ctx->cfg->pcap_file[1] == 0)
xpcapng_dump_flush(ctx->pcapng_dumper);
} else if (ctx->pcap_dumper) {
struct pcap_pkthdr h;
h.ts.tv_sec = ts / 1000000000ULL;
h.ts.tv_usec = ts % 1000000000ULL / 1000;
h.caplen = min(e->metadata.cap_len, ctx->cfg->snaplen);
h.len = e->metadata.pkt_len;
pcap_dump((u_char *) ctx->pcap_dumper, &h,
e->packet);
if (ctx->cfg->pcap_file[0] == '-' &&
ctx->cfg->pcap_file[1] == 0)
pcap_dump_flush(ctx->pcap_dumper);
} else {
int i;
char hline[SNPRINTH_MIN_BUFFER_SIZE];
if (ctx->cfg->hex_dump) {
printf("%llu.%09lld: %s()@%s%s: packet size %u "
"bytes, captured %u bytes on if_index "
"%u, rx queue %u, id %"PRIu64"\n",
ts / 1000000000ULL,
ts % 1000000000ULL,
xdp_func,
fexit ? "exit" : "entry",
fexit ? get_xdp_action_string(
e->metadata.action) : "",
e->metadata.pkt_len,
e->metadata.cap_len,
e->metadata.ifindex,
e->metadata.rx_queue,
ctx->cpu_packet_id[cpu]);
for (i = 0; i < e->metadata.cap_len; i += 16) {
snprinth(hline, sizeof(hline),
e->packet,
e->metadata.cap_len, i);
printf(" %s\n", hline);
}
} else {
printf("%llu.%09lld: %s()@%s%s: packet size %u "
"bytes on if_index %u, rx queue %u, "
"id %"PRIu64"\n",
ts / 1000000000ULL,
ts % 1000000000ULL,
xdp_func,
fexit ? "exit" : "entry",
fexit ? get_xdp_action_string(
e->metadata.action) : "",
e->metadata.pkt_len,e->metadata.ifindex,
e->metadata.rx_queue,
ctx->cpu_packet_id[cpu]);
}
}
ctx->captured_packets++;
break;
case PERF_RECORD_LOST:
ctx->missed_events += lost->lost;
ctx->last_missed_events += lost->lost;
break;
}
return LIBBPF_PERF_EVENT_CONT;
}
/*****************************************************************************
* get_epoch_to_uptime_delta()
*****************************************************************************/
static int get_epoch_to_uptime_delta(uint64_t *delta)
{
/* This function will calculate the rough delta between uptime
* seconds and the epoch time. This is not a precise delta as there is
* a delay between calling the two functions below (and time() being in
* seconds), but it's good enough to get a general offset. The delta
* between packets is still based on the timestamps from the trace
* infrastructure.
*/
struct timespec ts;
uint64_t uptime;
uint64_t epoch = time(NULL) * 1000000000ULL;
if (clock_gettime(CLOCK_MONOTONIC, &ts)) {
pr_warn("ERROR: Failed to get CLOCK_MONOTONIC time: %s(%d)",
strerror(errno), errno);
return -errno;
}
uptime = ts.tv_sec * 1000000000ULL + ts.tv_nsec;
*delta = epoch - uptime;
return 0;
}
/*****************************************************************************
* capture_on_legacy_interface()
*****************************************************************************/
static bool capture_on_legacy_interface(struct dumpopt *cfg)
{
bool rc = false;
char errbuf[PCAP_ERRBUF_SIZE];
uint64_t captured_packets = 0;
pcap_t *pcap = NULL;
pcap_dumper_t *pcap_dumper = NULL;
struct pcap_stat ps;
/* Open pcap handle for live capture. */
if (cfg->rx_capture != RX_FLAG_FENTRY) {
pr_warn("ERROR: For legacy capture only \"--rx-capture entry\""
" is supported!\n");
goto error_exit;
}
pcap = pcap_open_live(cfg->iface.ifname, cfg->snaplen,
cfg->promiscuous, 1000, errbuf);
if (pcap == NULL) {
pr_warn("ERROR: Can't open pcap live interface: %s\n", errbuf);
goto error_exit;
}
/* Open the pcap handle for pcap file. */
if (cfg->pcap_file) {
pcap_dumper = pcap_dump_open(pcap, cfg->pcap_file);
if (!pcap_dumper) {
pr_warn("ERROR: Can't open pcap file for writing!\n");
goto error_exit;
}
}
/* No more error conditions, display some capture information */
fprintf(stderr, "listening on %s, link-type %s (%s), "
"capture size %d bytes\n", cfg->iface.ifname,
pcap_datalink_val_to_name(pcap_datalink(pcap)),
pcap_datalink_val_to_description(pcap_datalink(pcap)),
cfg->snaplen);
/* Loop for receive packets on live interface. */
exit_pcap = pcap;
while (!exit_xdpdump) {
const uint8_t *packet;
struct pcap_pkthdr h;
packet = pcap_next(pcap, &h);
if (!packet)
continue;
if (pcap_dumper) {
pcap_dump((u_char *) pcap_dumper, &h, packet);
if (cfg->pcap_file[0] == '-' && cfg->pcap_file[1] == 0)
pcap_dump_flush(pcap_dumper);
} else {
size_t i;
char hline[SNPRINTH_MIN_BUFFER_SIZE];
if (cfg->hex_dump) {
printf("%ld.%06ld: packet size %u bytes, "
"captured %u bytes on if_name \"%s\"\n",
(long) h.ts.tv_sec, (long) h.ts.tv_usec,
h.len, h.caplen, cfg->iface.ifname);
for (i = 0; i < h.caplen; i += 16) {
snprinth(hline, sizeof(hline),
packet, h.caplen, i);
printf(" %s\n", hline);
}
} else {
printf("%ld.%06ld: packet size %u bytes on "
"if_name \"%s\"\n",
(long) h.ts.tv_sec, (long) h.ts.tv_usec,
h.len, cfg->iface.ifname);
}
}
captured_packets++;
}
exit_pcap = NULL;
rc = true;
fprintf(stderr, "\n%"PRIu64" packets captured\n", captured_packets);
if (pcap_stats(pcap, &ps) == 0) {
fprintf(stderr, "%u packets dropped by kernel\n", ps.ps_drop);
if (ps.ps_ifdrop != 0)
fprintf(stderr, "%u packets dropped by interface\n",
ps.ps_ifdrop);
}
error_exit:
if (pcap_dumper)
pcap_dump_close(pcap_dumper);
if (pcap)
pcap_close(pcap);
return rc;
}
/*****************************************************************************
* append_snprintf()
*****************************************************************************/
int append_snprintf(char **buf, size_t *buf_len, size_t *offset,
const char *format, ...)
{
int len;
va_list args;
if (buf == NULL || *buf == NULL || buf_len == NULL || *buf_len <= 0 ||
offset == NULL || *buf_len - *offset <= 0)
return -EINVAL;
while (true) {
char *new_buf;
size_t new_buf_len;
va_start(args, format);
len = vsnprintf(*buf + *offset, *buf_len - *offset, format, args);
va_end(args);
if ((size_t)len < (*buf_len - *offset)) {
*offset += len;
len = 0;
break;
}
if (*buf_len >= 2048)
return -ENOMEM;
new_buf_len = *buf_len * 2;
new_buf = realloc(*buf, new_buf_len);
if (!new_buf)
return -ENOMEM;
*buf = new_buf;
*buf_len = new_buf_len;
}
return len;
}
/*****************************************************************************
* get_program_names_all()
*****************************************************************************/
static char *get_program_names_all(struct capture_programs *progs, int skip_index)
{
char *program_names;
size_t size = 128;
size_t offset = 0;
program_names = malloc(size);
if (!program_names)
return NULL;
for (unsigned int i = 0; i < progs->nr_of_progs; i++) {
const char *kname = xdp_program__name(progs->progs[i].prog);
const char *fname = progs->progs[i].func;
uint32_t id = xdp_program__id(progs->progs[i].prog);
if (skip_index != (int)i) {
if (append_snprintf(&program_names, &size, &offset,
"%s%s@%d", i == 0 ? "" : ",",
fname ? fname : kname, id) < 0) {
free(program_names);
return NULL;
}
} else {
if (append_snprintf(&program_names, &size, &offset,
"%s%s@%d", i == 0 ? "" : ",",
"<function_name>", id) < 0) {
free(program_names);
return NULL;
}
}
}
return program_names;
}
/*****************************************************************************
* find_func_matches()
*****************************************************************************/
static size_t find_func_matches(const struct btf *btf,
const char *func_name,
const char **found_name,
bool print, int print_id, bool exact)
{
const struct btf_type *t, *match;
size_t len, matches = 0;
const char *name;
int nr_types, i;
if (!btf) {
pr_debug("No BTF found for program\n");
return 0;
}
len = strlen(func_name);
nr_types = btf__type_cnt(btf);
for (i = 1; i < nr_types; i++) {
t = btf__type_by_id(btf, i);
if (!btf_is_func(t))
continue;
name = btf__name_by_offset(btf, t->name_off);
if (!strncmp(name, func_name, len)) {
pr_debug("Found func %s matching %s\n",
name, func_name);
if (print) {
if (print_id < 0)
pr_warn(" %s\n", name);
else
pr_warn(" %s@%d\n", name, print_id);
}
/* Do an exact match if the user specified a function
* name, or if there is no possibility of truncation
* because the length is different from the truncated
* length.
*/
if (strlen(name) == len &&
(exact || len != BPF_OBJ_NAME_LEN - 1)) {
*found_name = name;
return 1; /* exact match */
}
/* prefix, may not be unique */
matches++;
match = t;
}
}
if (exact)
return 0;
if (matches == 1)
*found_name = btf__name_by_offset(btf, match->name_off);
return matches;
}
/*****************************************************************************
* match_target_function()
*****************************************************************************/
static int match_target_function(struct dumpopt *cfg,
struct capture_programs *all_progs,
char *prog_name, int prog_id)
{
int i;
unsigned int matches = 0;
for (i = 0; i < (int)all_progs->nr_of_progs; i++) {
const char *kname = xdp_program__name(all_progs->progs[i].prog);
if (prog_id != -1 &&
xdp_program__id(all_progs->progs[i].prog) != (uint32_t) prog_id)
continue;
if (!strncmp(kname, prog_name, strlen(kname))) {
if (all_progs->progs[i].func == NULL) {
if (find_func_matches(xdp_program__btf(all_progs->progs[i].prog),
prog_name,
&all_progs->progs[i].func,
false, -1,
true) == 1) {
all_progs->progs[i].rx_capture = cfg->rx_capture;
matches++;
} else if (strlen(prog_name) <= BPF_OBJ_NAME_LEN - 1) {
/* If the user cut and paste the
* truncated function name, make sure
* we tell him all the possible options!
*/
matches = UINT_MAX;
break;
}
} else if (!strcmp(all_progs->progs[i].func, prog_name)) {
all_progs->progs[i].rx_capture = cfg->rx_capture;
matches++;
}
}
if (prog_id != -1)
break;
}
if (!matches) {
if (prog_id == -1)
pr_warn("ERROR: Can't find function '%s' on interface!\n",
prog_name);
else
pr_warn("ERROR: Can't find function '%s' in interface program %d!\n",
prog_name, prog_id);
return -ENOENT;
} else if (matches == 1) {
return 0;
}
if (matches != UINT_MAX) {
pr_warn("ERROR: The function '%s' exists in multiple programs!\n",
prog_name);
} else {
if (prog_id == -1)
pr_warn("ERROR: Can't identify the full XDP '%s' function!\n",
prog_name);
else
pr_warn("ERROR: Can't identify the full XDP '%s' function in program %d!\n",
prog_name, prog_id);
}
pr_warn("The following is a list of candidates:\n");
for (i = 0; i < (int)all_progs->nr_of_progs; i++) {
uint32_t cur_prog_id = xdp_program__id(all_progs->progs[i].prog);
const char *func_dummy;
if (prog_id != -1 && cur_prog_id != (uint32_t) prog_id)
continue;
find_func_matches(xdp_program__btf(all_progs->progs[i].prog),
xdp_program__name(all_progs->progs[i].prog),
&func_dummy, true,
(prog_id == -1 &&
matches == UINT_MAX) ? -1 : (int) cur_prog_id,
false);
if (prog_id != -1)
break;
}
pr_warn("Please use the -p option to pick the correct one.\n");
if (!strcmp("all", cfg->program_names)) {
char *program_names = get_program_names_all(all_progs, i);
if (program_names) {
pr_warn("Command line to replace 'all':\n %s\n",
program_names);
free(program_names);
}
}
return -EAGAIN;
}
/*****************************************************************************
* check_btf()
*****************************************************************************/
static bool check_btf(struct xdp_program *prog)
{
if (xdp_program__btf(prog))
return true;
pr_warn("ERROR: xdpdump requires BTF information, but that is missing "
"from the loaded XDP program!\n");
return false;
}
/*****************************************************************************
* find_target()
*
* What is this function trying to do? It will return a list of programs to
* capture on, based on the configured program-names. If this parameter is
* not given, it will attach to the first (main) program.
*
* Note that the kernel API will truncate function names at BPF_OBJ_NAME_LEN
* so we need to guess the correct function if not explicitly given with
* the program-names option.
*
*****************************************************************************/
static int find_target(struct dumpopt *cfg, struct xdp_multiprog *mp,
struct capture_programs *tgt_progs)
{
const char *func;
struct xdp_program *prog, *p;
struct capture_programs progs;
size_t matches;
char *prog_name;
char *prog_safe_ptr;
char *program_names = cfg->program_names;
prog = xdp_multiprog__main_prog(mp);
if (!check_btf(prog))
return -EINVAL;
/* First take care of the default case, i.e. no function supplied */
if (!program_names) {
/* The libxdp code optimization where it skips the dispatcher
* if only one program is loaded. If this is the case, we need
* to attach to the actual first program, not the dispatcher.
*/
if (xdp_multiprog__program_count(mp) == 1) {
prog = xdp_multiprog__next_prog(NULL, mp);
if (!check_btf(prog))
return -EINVAL;
}
matches = find_func_matches(xdp_program__btf(prog),
xdp_program__name(prog),
&func, false, -1, false);
if (!matches) {
pr_warn("ERROR: Can't find function '%s' on interface!\n",
xdp_program__name(prog));
return -ENOENT;
} else if (matches == 1) {
tgt_progs->nr_of_progs = 1;