/*
* Copyright (C) 2017 Netronome Systems, Inc.
*
* This software is dual licensed under the GNU General License Version 2,
* June 1991 as shown in the file COPYING in the top-level directory of this
* source tree or the BSD 2-Clause License provided below. You have the
* option to license this software under the complete terms of either license.
*
* The BSD 2-Clause License:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* 1. Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* 2. Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
/* Author: Jakub Kicinski <kubakici@wp.pl> */
#include <errno.h>
#include <libgen.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <linux/limits.h>
#include <linux/magic.h>
#include <sys/mount.h>
#include <sys/types.h>
#include <sys/vfs.h>
#include <bpf.h>
#include "main.h"
void p_err(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
if (json_output) {
jsonw_start_object(json_wtr);
jsonw_name(json_wtr, "error");
jsonw_vprintf_enquote(json_wtr, fmt, ap);
jsonw_end_object(json_wtr);
} else {
fprintf(stderr, "Error: ");
vfprintf(stderr, fmt, ap);
fprintf(stderr, "\n");
}
va_end(ap);
}
void p_info(const char *fmt, ...)
{
va_list ap;
if (json_output)
return;
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
fprintf(stderr, "\n");
va_end(ap);
}
static bool is_bpffs(char *path)
{
struct statfs st_fs;
if (statfs(path, &st_fs) < 0)
return false;
return (unsigned long)st_fs.f_type == BPF_FS_MAGIC;
}
static int mnt_bpffs(const char *target, char *buff, size_t bufflen)
{
bool bind_done = false;
while (mount("", target, "none", MS_PRIVATE | MS_REC, NULL)) {
if (errno != EINVAL || bind_done) {
snprintf(buff, bufflen,
"mount --make-private %s failed: %s",
target, strerror(errno));
return -1;
}
if (mount(target, target, "none", MS_BIND, NULL)) {
snprintf(buff, bufflen,
"mount --bind %s %s failed: %s",
target, target, strerror(errno));
return -1;
}
bind_done = true;
}
if (mount("bpf", target, "bpf", 0, "mode=0700")) {
snprintf(buff, bufflen, "mount -t bpf bpf %s failed: %s",
target, strerror(errno));
return -1;
}
return 0;
}
int open_obj_pinned_any(char *path, enum bpf_obj_type exp_type)
{
enum bpf_obj_type type;
int fd;
fd = bpf_obj_get(path);
if (fd < 0) {
p_err("bpf obj get (%s): %s", path,
errno == EACCES && !is_bpffs(dirname(path)) ?
"directory not in bpf file system (bpffs)" :
strerror(errno));
return -1;
}
type = get_fd_type(fd);
if (type < 0) {
close(fd);
return type;
}
if (type != exp_type) {
p_err("incorrect object type: %s", get_fd_type_name(type));
close(fd);
return -1;
}
return fd;
}
int do_pin_any(int argc, char **argv, int (*get_fd_by_id)(__u32))
{
char err_str[ERR_MAX_LEN];
unsigned int id;
char *endptr;
char *file;
char *dir;
int err;
int fd;
if (!is_prefix(*argv, "id")) {
p_err("expected 'id' got %s", *argv);
return -1;
}
NEXT_ARG();
id = strtoul(*argv, &endptr, 0);
if (*endptr) {
p_err("can't parse %s as ID", *argv);
return -1;
}
NEXT_ARG();
if (argc != 1)
usage();
fd = get_fd_by_id(id);
if (fd < 0) {
p_err("can't get prog by id (%u): %s", id, strerror(errno));
return -1;
}
err = bpf_obj_pin(fd, *argv);
if (!err)
goto out_close;
file = malloc(strlen(*argv) + 1);
strcpy(file, *argv);
dir = dirname(file);
if (errno != EPERM || is_bpffs(dir)) {
p_err("can't pin the object (%s): %s", *argv, strerror(errno));
goto out_free;
}
/* Attempt to mount bpffs, then retry pinning. */
err = mnt_bpffs(dir, err_str, ERR_MAX_LEN);
if (!err) {
err = bpf_obj_pin(fd, *argv);
if (err)
p_err("can't pin the object (%s): %s", *argv,
strerror(errno));
} else {
err_str[ERR_MAX_LEN - 1] = '\0';
p_err("can't mount BPF file system to pin the object (%s): %s",
*argv, err_str);
}
out_free:
free(file);
out_close:
close(fd);
return err;
}
const char *get_fd_type_name(enum bpf_obj_type type)
{
static const char * const names[] = {
[BPF_OBJ_UNKNOWN] = "unknown",
[BPF_OBJ_PROG] = "prog",
[BPF_OBJ_MAP] = "map",
};
if (type < 0 || type >= ARRAY_SIZE(names) || !names[type])
return names[BPF_OBJ_UNKNOWN];
return names[type];
}
int get_fd_type(int fd)
{
char path[PATH_MAX];
char buf[512];
ssize_t n;
snprintf(path, sizeof(path), "/proc/%d/fd/%d", getpid(), fd);
n = readlink(path, buf, sizeof(buf));
if (n < 0) {
p_err("can't read link type: %s", strerror(errno));
return -1;
}
if (n == sizeof(path)) {
p_err("can't read link type: path too long!");
return -1;
}
if (strstr(buf, "bpf-map"))
return BPF_OBJ_MAP;
else if (strstr(buf, "bpf-prog"))
return BPF_OBJ_PROG;
return BPF_OBJ_UNKNOWN;
}
char *get_fdinfo(int fd, const char *key)
{
char path[PATH_MAX];
char *line = NULL;
size_t line_n = 0;
ssize_t n;
FILE *fdi;
snprintf(path, sizeof(path), "/proc/%d/fdinfo/%d", getpid(), fd);
fdi = fopen(path, "r");
if (!fdi) {
p_err("can't open fdinfo: %s", strerror(errno));
return NULL;
}
while ((n = getline(&line, &line_n, fdi))) {
char *value;
int len;
if (!strstr(line, key))
continue;
fclose(fdi);
value = strchr(line, '\t');
if (!value || !value[1]) {
p_err("malformed fdinfo!?");
free(line);
return NULL;
}
value++;
len = strlen(value);
memmove(line, value, len);
line[len - 1] = '\0';
return line;
}
p_err("key '%s' not found in fdinfo", key);
free(line);
fclose(fdi);
return NULL;
}
void print_hex_data_json(uint8_t *data, size_t len)
{
unsigned int i;
jsonw_start_array(json_wtr);
for (i = 0; i < len; i++)
jsonw_printf(json_wtr, "\"0x%02hhx\"", data[i]);
jsonw_end_array(json_wtr);
}
