text: // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
  /* Copyright (C) 2017-2018 Netronome Systems, Inc. */
  
  #define _GNU_SOURCE
  #include <ctype.h>
  #include <errno.h>
  #include <fcntl.h>
  #include <ftw.h>
  #include <libgen.h>
  #include <mntent.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 <net/if.h>
  #include <sys/mount.h>
  #include <sys/resource.h>
  #include <sys/stat.h>
  #include <sys/vfs.h>
  
  #include <bpf/bpf.h>
  #include <bpf/libbpf.h> /* libbpf_num_possible_cpus */
  
  #include "main.h"
  
  #ifndef BPF_FS_MAGIC
  #define BPF_FS_MAGIC		0xcafe4a11
  #endif
  
  const char * const attach_type_name[__MAX_BPF_ATTACH_TYPE] = {
  	[BPF_CGROUP_INET_INGRESS]	= "ingress",
  	[BPF_CGROUP_INET_EGRESS]	= "egress",
  	[BPF_CGROUP_INET_SOCK_CREATE]	= "sock_create",
  	[BPF_CGROUP_INET_SOCK_RELEASE]	= "sock_release",
  	[BPF_CGROUP_SOCK_OPS]		= "sock_ops",
  	[BPF_CGROUP_DEVICE]		= "device",
  	[BPF_CGROUP_INET4_BIND]		= "bind4",
  	[BPF_CGROUP_INET6_BIND]		= "bind6",
  	[BPF_CGROUP_INET4_CONNECT]	= "connect4",
  	[BPF_CGROUP_INET6_CONNECT]	= "connect6",
  	[BPF_CGROUP_INET4_POST_BIND]	= "post_bind4",
  	[BPF_CGROUP_INET6_POST_BIND]	= "post_bind6",
  	[BPF_CGROUP_INET4_GETPEERNAME]	= "getpeername4",
  	[BPF_CGROUP_INET6_GETPEERNAME]	= "getpeername6",
  	[BPF_CGROUP_INET4_GETSOCKNAME]	= "getsockname4",
  	[BPF_CGROUP_INET6_GETSOCKNAME]	= "getsockname6",
  	[BPF_CGROUP_UDP4_SENDMSG]	= "sendmsg4",
  	[BPF_CGROUP_UDP6_SENDMSG]	= "sendmsg6",
  	[BPF_CGROUP_SYSCTL]		= "sysctl",
  	[BPF_CGROUP_UDP4_RECVMSG]	= "recvmsg4",
  	[BPF_CGROUP_UDP6_RECVMSG]	= "recvmsg6",
  	[BPF_CGROUP_GETSOCKOPT]		= "getsockopt",
  	[BPF_CGROUP_SETSOCKOPT]		= "setsockopt",
  
  	[BPF_SK_SKB_STREAM_PARSER]	= "sk_skb_stream_parser",
  	[BPF_SK_SKB_STREAM_VERDICT]	= "sk_skb_stream_verdict",
  	[BPF_SK_MSG_VERDICT]		= "sk_msg_verdict",
  	[BPF_LIRC_MODE2]		= "lirc_mode2",
  	[BPF_FLOW_DISSECTOR]		= "flow_dissector",
  	[BPF_TRACE_RAW_TP]		= "raw_tp",
  	[BPF_TRACE_FENTRY]		= "fentry",
  	[BPF_TRACE_FEXIT]		= "fexit",
  	[BPF_MODIFY_RETURN]		= "mod_ret",
  	[BPF_LSM_MAC]			= "lsm_mac",
  	[BPF_SK_LOOKUP]			= "sk_lookup",
  };
  
  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;
  }
  
  void set_max_rlimit(void)
  {
  	struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY };
  
  	setrlimit(RLIMIT_MEMLOCK, &rinf);
  }
  
  static int
  mnt_fs(const char *target, const char *type, 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(type, target, type, 0, "mode=0700")) {
  		snprintf(buff, bufflen, "mount -t %s %s %s failed: %s",
  			 type, type, target, strerror(errno));
  		return -1;
  	}
  
  	return 0;
  }
  
  int mount_tracefs(const char *target)
  {
  	char err_str[ERR_MAX_LEN];
  	int err;
  
  	err = mnt_fs(target, "tracefs", err_str, ERR_MAX_LEN);
  	if (err) {
  		err_str[ERR_MAX_LEN - 1] = '\0';
  		p_err("can't mount tracefs: %s", err_str);
  	}
  
  	return err;
  }
  
  int open_obj_pinned(const char *path, bool quiet)
  {
  	char *pname;
  	int fd = -1;
  
  	pname = strdup(path);
  	if (!pname) {
  		if (!quiet)
  			p_err("mem alloc failed");
  		goto out_ret;
  	}
  
  	fd = bpf_obj_get(pname);
  	if (fd < 0) {
  		if (!quiet)
  			p_err("bpf obj get (%s): %s", pname,
  			      errno == EACCES && !is_bpffs(dirname(pname)) ?
  			    "directory not in bpf file system (bpffs)" :
  			    strerror(errno));
  		goto out_free;
  	}
  
  out_free:
  	free(pname);
  out_ret:
  	return fd;
  }
  
  int open_obj_pinned_any(const char *path, enum bpf_obj_type exp_type)
  {
  	enum bpf_obj_type type;
  	int fd;
  
  	fd = open_obj_pinned(path, false);
  	if (fd < 0)
  		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 mount_bpffs_for_pin(const char *name)
  {
  	char err_str[ERR_MAX_LEN];
  	char *file;
  	char *dir;
  	int err = 0;
  
  	file = malloc(strlen(name) + 1);
  	strcpy(file, name);
  	dir = dirname(file);
  
  	if (is_bpffs(dir))
  		/* nothing to do if already mounted */
  		goto out_free;
  
  	if (block_mount) {
  		p_err("no BPF file system found, not mounting it due to --nomount option");
  		err = -1;
  		goto out_free;
  	}
  
  	err = mnt_fs(dir, "bpf", err_str, ERR_MAX_LEN);
  	if (err) {
  		err_str[ERR_MAX_LEN - 1] = '\0';
  		p_err("can't mount BPF file system to pin the object (%s): %s",
  		      name, err_str);
  	}
  
  out_free:
  	free(file);
  	return err;
  }
  
  int do_pin_fd(int fd, const char *name)
  {
  	int err;
  
  	err = mount_bpffs_for_pin(name);
  	if (err)
  		return err;
  
  	err = bpf_obj_pin(fd, name);
  	if (err)
  		p_err("can't pin the object (%s): %s", name, strerror(errno));
  
  	return err;
  }
  
  int do_pin_any(int argc, char **argv, int (*get_fd)(int *, char ***))
  {
  	int err;
  	int fd;
  
  	fd = get_fd(&argc, &argv);
  	if (fd < 0)
  		return fd;
  
  	err = do_pin_fd(fd, *argv);
  
  	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/self/fd/%d", 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;
  	else if (strstr(buf, "bpf-link"))
  		return BPF_OBJ_LINK;
  
  	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/self/fdinfo/%d", fd);
  
  	fdi = fopen(path, "r");
  	if (!fdi)
  		return NULL;
  
  	while ((n = getline(&line, &line_n, fdi)) > 0) {
  		char *value;
  		int len;
  
  		if (!strstr(line, key))
  			continue;
  
  		fclose(fdi);
  
  		value = strchr(line, '\t');
  		if (!value || !value[1]) {
  			free(line);
  			return NULL;
  		}
  		value++;
  
  		len = strlen(value);
  		memmove(line, value, len);
  		line[len - 1] = '\0';
  
  		return line;
  	}
  
  	free(line);
  	fclose(fdi);
  	return NULL;
  }
  
  void print_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, "%d", data[i]);
  	jsonw_end_array(json_wtr);
  }
  
  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);
  }
  
  /* extra params for nftw cb */
  static struct pinned_obj_table *build_fn_table;
  static enum bpf_obj_type build_fn_type;
  
  static int do_build_table_cb(const char *fpath, const struct stat *sb,
  			     int typeflag, struct FTW *ftwbuf)
  {
  	struct bpf_prog_info pinned_info;
  	__u32 len = sizeof(pinned_info);
  	struct pinned_obj *obj_node;
  	enum bpf_obj_type objtype;
  	int fd, err = 0;
  
  	if (typeflag != FTW_F)
  		goto out_ret;
  
  	fd = open_obj_pinned(fpath, true);
  	if (fd < 0)
  		goto out_ret;
  
  	objtype = get_fd_type(fd);
  	if (objtype != build_fn_type)
  		goto out_close;
  
  	memset(&pinned_info, 0, sizeof(pinned_info));
  	if (bpf_obj_get_info_by_fd(fd, &pinned_info, &len))
  		goto out_close;
  
  	obj_node = calloc(1, sizeof(*obj_node));
  	if (!obj_node) {
  		err = -1;
  		goto out_close;
  	}
  
  	obj_node->id = pinned_info.id;
  	obj_node->path = strdup(fpath);
  	if (!obj_node->path) {
  		err = -1;
  		free(obj_node);
  		goto out_close;
  	}
  
  	hash_add(build_fn_table->table, &obj_node->hash, obj_node->id);
  out_close:
  	close(fd);
  out_ret:
  	return err;
  }
  
  int build_pinned_obj_table(struct pinned_obj_table *tab,
  			   enum bpf_obj_type type)
  {
  	struct mntent *mntent = NULL;
  	FILE *mntfile = NULL;
  	int flags = FTW_PHYS;
  	int nopenfd = 16;
  	int err = 0;
  
  	mntfile = setmntent("/proc/mounts", "r");
  	if (!mntfile)
  		return -1;
  
  	build_fn_table = tab;
  	build_fn_type = type;
  
  	while ((mntent = getmntent(mntfile))) {
  		char *path = mntent->mnt_dir;
  
  		if (strncmp(mntent->mnt_type, "bpf", 3) != 0)
  			continue;
  		err = nftw(path, do_build_table_cb, nopenfd, flags);
  		if (err)
  			break;
  	}
  	fclose(mntfile);
  	return err;
  }
  
  void delete_pinned_obj_table(struct pinned_obj_table *tab)
  {
  	struct pinned_obj *obj;
  	struct hlist_node *tmp;
  	unsigned int bkt;
  
  	hash_for_each_safe(tab->table, bkt, tmp, obj, hash) {
  		hash_del(&obj->hash);
  		free(obj->path);
  		free(obj);
  	}
  }
  
  unsigned int get_page_size(void)
  {
  	static int result;
  
  	if (!result)
  		result = getpagesize();
  	return result;
  }
  
  unsigned int get_possible_cpus(void)
  {
  	int cpus = libbpf_num_possible_cpus();
  
  	if (cpus < 0) {
  		p_err("Can't get # of possible cpus: %s", strerror(-cpus));
  		exit(-1);
  	}
  	return cpus;
  }
  
  static char *
  ifindex_to_name_ns(__u32 ifindex, __u32 ns_dev, __u32 ns_ino, char *buf)
  {
  	struct stat st;
  	int err;
  
  	err = stat("/proc/self/ns/net", &st);
  	if (err) {
  		p_err("Can't stat /proc/self: %s", strerror(errno));
  		return NULL;
  	}
  
  	if (st.st_dev != ns_dev || st.st_ino != ns_ino)
  		return NULL;
  
  	return if_indextoname(ifindex, buf);
  }
  
  static int read_sysfs_hex_int(char *path)
  {
  	char vendor_id_buf[8];
  	int len;
  	int fd;
  
  	fd = open(path, O_RDONLY);
  	if (fd < 0) {
  		p_err("Can't open %s: %s", path, strerror(errno));
  		return -1;
  	}
  
  	len = read(fd, vendor_id_buf, sizeof(vendor_id_buf));
  	close(fd);
  	if (len < 0) {
  		p_err("Can't read %s: %s", path, strerror(errno));
  		return -1;
  	}
  	if (len >= (int)sizeof(vendor_id_buf)) {
  		p_err("Value in %s too long", path);
  		return -1;
  	}
  
  	vendor_id_buf[len] = 0;
  
  	return strtol(vendor_id_buf, NULL, 0);
  }
  
  static int read_sysfs_netdev_hex_int(char *devname, const char *entry_name)
  {
  	char full_path[64];
  
  	snprintf(full_path, sizeof(full_path), "/sys/class/net/%s/device/%s",
  		 devname, entry_name);
  
  	return read_sysfs_hex_int(full_path);
  }
  
  const char *
  ifindex_to_bfd_params(__u32 ifindex, __u64 ns_dev, __u64 ns_ino,
  		      const char **opt)
  {
  	char devname[IF_NAMESIZE];
  	int vendor_id;
  	int device_id;
  
  	if (!ifindex_to_name_ns(ifindex, ns_dev, ns_ino, devname)) {
  		p_err("Can't get net device name for ifindex %d: %s", ifindex,
  		      strerror(errno));
  		return NULL;
  	}
  
  	vendor_id = read_sysfs_netdev_hex_int(devname, "vendor");
  	if (vendor_id < 0) {
  		p_err("Can't get device vendor id for %s", devname);
  		return NULL;
  	}
  
  	switch (vendor_id) {
  	case 0x19ee:
  		device_id = read_sysfs_netdev_hex_int(devname, "device");
  		if (device_id != 0x4000 &&
  		    device_id != 0x6000 &&
  		    device_id != 0x6003)
  			p_info("Unknown NFP device ID, assuming it is NFP-6xxx arch");
  		*opt = "ctx4";
  		return "NFP-6xxx";
  	default:
  		p_err("Can't get bfd arch name for device vendor id 0x%04x",
  		      vendor_id);
  		return NULL;
  	}
  }
  
  void print_dev_plain(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
  {
  	char name[IF_NAMESIZE];
  
  	if (!ifindex)
  		return;
  
  	printf("  offloaded_to ");
  	if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
  		printf("%s", name);
  	else
  		printf("ifindex %u ns_dev %llu ns_ino %llu",
  		       ifindex, ns_dev, ns_inode);
  }
  
  void print_dev_json(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
  {
  	char name[IF_NAMESIZE];
  
  	if (!ifindex)
  		return;
  
  	jsonw_name(json_wtr, "dev");
  	jsonw_start_object(json_wtr);
  	jsonw_uint_field(json_wtr, "ifindex", ifindex);
  	jsonw_uint_field(json_wtr, "ns_dev", ns_dev);
  	jsonw_uint_field(json_wtr, "ns_inode", ns_inode);
  	if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
  		jsonw_string_field(json_wtr, "ifname", name);
  	jsonw_end_object(json_wtr);
  }
  
  int parse_u32_arg(int *argc, char ***argv, __u32 *val, const char *what)
  {
  	char *endptr;
  
  	NEXT_ARGP();
  
  	if (*val) {
  		p_err("%s already specified", what);
  		return -1;
  	}
  
  	*val = strtoul(**argv, &endptr, 0);
  	if (*endptr) {
  		p_err("can't parse %s as %s", **argv, what);
  		return -1;
  	}
  	NEXT_ARGP();
  
  	return 0;
  }
  
  int __printf(2, 0)
  print_all_levels(__maybe_unused enum libbpf_print_level level,
  		 const char *format, va_list args)
  {
  	return vfprintf(stderr, format, args);
  }
  
  static int prog_fd_by_nametag(void *nametag, int **fds, bool tag)
  {
  	unsigned int id = 0;
  	int fd, nb_fds = 0;
  	void *tmp;
  	int err;
  
  	while (true) {
  		struct bpf_prog_info info = {};
  		__u32 len = sizeof(info);
  
  		err = bpf_prog_get_next_id(id, &id);
  		if (err) {
  			if (errno != ENOENT) {
  				p_err("%s", strerror(errno));
  				goto err_close_fds;
  			}
  			return nb_fds;
  		}
  
  		fd = bpf_prog_get_fd_by_id(id);
  		if (fd < 0) {
  			p_err("can't get prog by id (%u): %s",
  			      id, strerror(errno));
  			goto err_close_fds;
  		}
  
  		err = bpf_obj_get_info_by_fd(fd, &info, &len);
  		if (err) {
  			p_err("can't get prog info (%u): %s",
  			      id, strerror(errno));
  			goto err_close_fd;
  		}
  
  		if ((tag && memcmp(nametag, info.tag, BPF_TAG_SIZE)) ||
  		    (!tag && strncmp(nametag, info.name, BPF_OBJ_NAME_LEN))) {
  			close(fd);
  			continue;
  		}
  
  		if (nb_fds > 0) {
  			tmp = realloc(*fds, (nb_fds + 1) * sizeof(int));
  			if (!tmp) {
  				p_err("failed to realloc");
  				goto err_close_fd;
  			}
  			*fds = tmp;
  		}
  		(*fds)[nb_fds++] = fd;
  	}
  
  err_close_fd:
  	close(fd);
  err_close_fds:
  	while (--nb_fds >= 0)
  		close((*fds)[nb_fds]);
  	return -1;
  }
  
  int prog_parse_fds(int *argc, char ***argv, int **fds)
  {
  	if (is_prefix(**argv, "id")) {
  		unsigned int id;
  		char *endptr;
  
  		NEXT_ARGP();
  
  		id = strtoul(**argv, &endptr, 0);
  		if (*endptr) {
  			p_err("can't parse %s as ID", **argv);
  			return -1;
  		}
  		NEXT_ARGP();
  
  		(*fds)[0] = bpf_prog_get_fd_by_id(id);
  		if ((*fds)[0] < 0) {
  			p_err("get by id (%u): %s", id, strerror(errno));
  			return -1;
  		}
  		return 1;
  	} else if (is_prefix(**argv, "tag")) {
  		unsigned char tag[BPF_TAG_SIZE];
  
  		NEXT_ARGP();
  
  		if (sscanf(**argv, BPF_TAG_FMT, tag, tag + 1, tag + 2,
  			   tag + 3, tag + 4, tag + 5, tag + 6, tag + 7)
  		    != BPF_TAG_SIZE) {
  			p_err("can't parse tag");
  			return -1;
  		}
  		NEXT_ARGP();
  
  		return prog_fd_by_nametag(tag, fds, true);
  	} else if (is_prefix(**argv, "name")) {
  		char *name;
  
  		NEXT_ARGP();
  
  		name = **argv;
  		if (strlen(name) > BPF_OBJ_NAME_LEN - 1) {
  			p_err("can't parse name");
  			return -1;
  		}
  		NEXT_ARGP();
  
  		return prog_fd_by_nametag(name, fds, false);
  	} else if (is_prefix(**argv, "pinned")) {
  		char *path;
  
  		NEXT_ARGP();
  
  		path = **argv;
  		NEXT_ARGP();
  
  		(*fds)[0] = open_obj_pinned_any(path, BPF_OBJ_PROG);
  		if ((*fds)[0] < 0)
  			return -1;
  		return 1;
  	}
  
  	p_err("expected 'id', 'tag', 'name' or 'pinned', got: '%s'?", **argv);
  	return -1;
  }
  
  int prog_parse_fd(int *argc, char ***argv)
  {
  	int *fds = NULL;
  	int nb_fds, fd;
  
  	fds = malloc(sizeof(int));
  	if (!fds) {
  		p_err("mem alloc failed");
  		return -1;
  	}
  	nb_fds = prog_parse_fds(argc, argv, &fds);
  	if (nb_fds != 1) {
  		if (nb_fds > 1) {
  			p_err("several programs match this handle");
  			while (nb_fds--)
  				close(fds[nb_fds]);
  		}
  		fd = -1;
  		goto exit_free;
  	}
  
  	fd = fds[0];
  exit_free:
  	free(fds);
  	return fd;
  }
  
  static int map_fd_by_name(char *name, int **fds)
  {
  	unsigned int id = 0;
  	int fd, nb_fds = 0;
  	void *tmp;
  	int err;
  
  	while (true) {
  		struct bpf_map_info info = {};
  		__u32 len = sizeof(info);
  
  		err = bpf_map_get_next_id(id, &id);
  		if (err) {
  			if (errno != ENOENT) {
  				p_err("%s", strerror(errno));
  				goto err_close_fds;
  			}
  			return nb_fds;
  		}
  
  		fd = bpf_map_get_fd_by_id(id);
  		if (fd < 0) {
  			p_err("can't get map by id (%u): %s",
  			      id, strerror(errno));
  			goto err_close_fds;
  		}
  
  		err = bpf_obj_get_info_by_fd(fd, &info, &len);
  		if (err) {
  			p_err("can't get map info (%u): %s",
  			      id, strerror(errno));
  			goto err_close_fd;
  		}
  
  		if (strncmp(name, info.name, BPF_OBJ_NAME_LEN)) {
  			close(fd);
  			continue;
  		}
  
  		if (nb_fds > 0) {
  			tmp = realloc(*fds, (nb_fds + 1) * sizeof(int));
  			if (!tmp) {
  				p_err("failed to realloc");
  				goto err_close_fd;
  			}
  			*fds = tmp;
  		}
  		(*fds)[nb_fds++] = fd;
  	}
  
  err_close_fd:
  	close(fd);
  err_close_fds:
  	while (--nb_fds >= 0)
  		close((*fds)[nb_fds]);
  	return -1;
  }
  
  int map_parse_fds(int *argc, char ***argv, int **fds)
  {
  	if (is_prefix(**argv, "id")) {
  		unsigned int id;
  		char *endptr;
  
  		NEXT_ARGP();
  
  		id = strtoul(**argv, &endptr, 0);
  		if (*endptr) {
  			p_err("can't parse %s as ID", **argv);
  			return -1;
  		}
  		NEXT_ARGP();
  
  		(*fds)[0] = bpf_map_get_fd_by_id(id);
  		if ((*fds)[0] < 0) {
  			p_err("get map by id (%u): %s", id, strerror(errno));
  			return -1;
  		}
  		return 1;
  	} else if (is_prefix(**argv, "name")) {
  		char *name;
  
  		NEXT_ARGP();
  
  		name = **argv;
  		if (strlen(name) > BPF_OBJ_NAME_LEN - 1) {
  			p_err("can't parse name");
  			return -1;
  		}
  		NEXT_ARGP();
  
  		return map_fd_by_name(name, fds);
  	} else if (is_prefix(**argv, "pinned")) {
  		char *path;
  
  		NEXT_ARGP();
  
  		path = **argv;
  		NEXT_ARGP();
  
  		(*fds)[0] = open_obj_pinned_any(path, BPF_OBJ_MAP);
  		if ((*fds)[0] < 0)
  			return -1;
  		return 1;
  	}
  
  	p_err("expected 'id', 'name' or 'pinned', got: '%s'?", **argv);
  	return -1;
  }
  
  int map_parse_fd(int *argc, char ***argv)
  {
  	int *fds = NULL;
  	int nb_fds, fd;
  
  	fds = malloc(sizeof(int));
  	if (!fds) {
  		p_err("mem alloc failed");
  		return -1;
  	}
  	nb_fds = map_parse_fds(argc, argv, &fds);
  	if (nb_fds != 1) {
  		if (nb_fds > 1) {
  			p_err("several maps match this handle");
  			while (nb_fds--)
  				close(fds[nb_fds]);
  		}
  		fd = -1;
  		goto exit_free;
  	}
  
  	fd = fds[0];
  exit_free:
  	free(fds);
  	return fd;
  }
  
  int map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len)
  {
  	int err;
  	int fd;
  
  	fd = map_parse_fd(argc, argv);
  	if (fd < 0)
  		return -1;
  
  	err = bpf_obj_get_info_by_fd(fd, info, info_len);
  	if (err) {
  		p_err("can't get map info: %s", strerror(errno));
  		close(fd);
  		return err;
  	}
  
  	return fd;
  }
  