Commit 37081156 authored by Alexei Starovoitov's avatar Alexei Starovoitov
Browse files

Merge branch 'libbpf-minimize-feature-detection' 



Andrii Nakryiko says:

====================
Get rid of two feature detectors: reallocarray and libelf-mmap. Optional
feature detections complicate libbpf Makefile and cause more troubles for
various applications that want to integrate libbpf as part of their build.

Patch #1 replaces all reallocarray() uses into libbpf-internal reallocarray()
implementation. Patches #2 and #3 makes sure we won't re-introduce
reallocarray() accidentally. Patch #2 also removes last use of
libbpf_internal.h header inside bpftool. There is still nlattr.h that's used
by both libbpf and bpftool, but that's left for a follow up patch to split.
Patch #4 removed libelf-mmap feature detector and all its uses, as it's
trivial to handle missing mmap support in libbpf, the way objtool has been
doing it for a while.

v1->v2 and v2->v3:
  - rebase to latest bpf-next (Alexei).
====================

Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parents 00b2e953 22dd1ac9

tools/bpf/bpftool/gen.c

+0 −2
Original line number Diff line number Diff line
@@ -19,11 +19,9 @@ 
#include <sys/mman.h>

#include <bpf/btf.h>



#include "bpf/libbpf_internal.h"

#include "json_writer.h"

#include "main.h"





#define MAX_OBJ_NAME_LEN 64



static void sanitize_identifier(char *name)

tools/bpf/bpftool/net.c

+282 −17
Original line number Diff line number Diff line
@@ -6,22 +6,27 @@ 
#include <fcntl.h>

#include <stdlib.h>

#include <string.h>

#include <time.h>

#include <unistd.h>

#include <bpf/bpf.h>

#include <bpf/libbpf.h>

#include <net/if.h>

#include <linux/if.h>

#include <linux/rtnetlink.h>

#include <linux/socket.h>

#include <linux/tc_act/tc_bpf.h>

#include <sys/socket.h>

#include <sys/stat.h>

#include <sys/types.h>



#include "bpf/nlattr.h"

#include "bpf/libbpf_internal.h"

#include "main.h"

#include "netlink_dumper.h"



#ifndef SOL_NETLINK

#define SOL_NETLINK 270

#endif



struct ip_devname_ifindex {

	char	devname[64];

	int	ifindex;
@@ -85,6 +90,266 @@ static enum net_attach_type parse_attach_type(const char *str) 
	return net_attach_type_size;

}



typedef int (*dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb);



typedef int (*__dump_nlmsg_t)(struct nlmsghdr *nlmsg, dump_nlmsg_t, void *cookie);



static int netlink_open(__u32 *nl_pid)

{

	struct sockaddr_nl sa;

	socklen_t addrlen;

	int one = 1, ret;

	int sock;



	memset(&sa, 0, sizeof(sa));

	sa.nl_family = AF_NETLINK;



	sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);

	if (sock < 0)

		return -errno;



	if (setsockopt(sock, SOL_NETLINK, NETLINK_EXT_ACK,

		       &one, sizeof(one)) < 0) {

		p_err("Netlink error reporting not supported");

	}



	if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {

		ret = -errno;

		goto cleanup;

	}



	addrlen = sizeof(sa);

	if (getsockname(sock, (struct sockaddr *)&sa, &addrlen) < 0) {

		ret = -errno;

		goto cleanup;

	}



	if (addrlen != sizeof(sa)) {

		ret = -LIBBPF_ERRNO__INTERNAL;

		goto cleanup;

	}



	*nl_pid = sa.nl_pid;

	return sock;



cleanup:

	close(sock);

	return ret;

}



static int netlink_recv(int sock, __u32 nl_pid, __u32 seq,

			    __dump_nlmsg_t _fn, dump_nlmsg_t fn,

			    void *cookie)

{

	bool multipart = true;

	struct nlmsgerr *err;

	struct nlmsghdr *nh;

	char buf[4096];

	int len, ret;



	while (multipart) {

		multipart = false;

		len = recv(sock, buf, sizeof(buf), 0);

		if (len < 0) {

			ret = -errno;

			goto done;

		}



		if (len == 0)

			break;



		for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, len);

		     nh = NLMSG_NEXT(nh, len)) {

			if (nh->nlmsg_pid != nl_pid) {

				ret = -LIBBPF_ERRNO__WRNGPID;

				goto done;

			}

			if (nh->nlmsg_seq != seq) {

				ret = -LIBBPF_ERRNO__INVSEQ;

				goto done;

			}

			if (nh->nlmsg_flags & NLM_F_MULTI)

				multipart = true;

			switch (nh->nlmsg_type) {

			case NLMSG_ERROR:

				err = (struct nlmsgerr *)NLMSG_DATA(nh);

				if (!err->error)

					continue;

				ret = err->error;

				libbpf_nla_dump_errormsg(nh);

				goto done;

			case NLMSG_DONE:

				return 0;

			default:

				break;

			}

			if (_fn) {

				ret = _fn(nh, fn, cookie);

				if (ret)

					return ret;

			}

		}

	}

	ret = 0;

done:

	return ret;

}



static int __dump_class_nlmsg(struct nlmsghdr *nlh,

			      dump_nlmsg_t dump_class_nlmsg,

			      void *cookie)

{

	struct nlattr *tb[TCA_MAX + 1], *attr;

	struct tcmsg *t = NLMSG_DATA(nlh);

	int len;



	len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));

	attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));

	if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)

		return -LIBBPF_ERRNO__NLPARSE;



	return dump_class_nlmsg(cookie, t, tb);

}



static int netlink_get_class(int sock, unsigned int nl_pid, int ifindex,

			     dump_nlmsg_t dump_class_nlmsg, void *cookie)

{

	struct {

		struct nlmsghdr nlh;

		struct tcmsg t;

	} req = {

		.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),

		.nlh.nlmsg_type = RTM_GETTCLASS,

		.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,

		.t.tcm_family = AF_UNSPEC,

		.t.tcm_ifindex = ifindex,

	};

	int seq = time(NULL);



	req.nlh.nlmsg_seq = seq;

	if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)

		return -errno;



	return netlink_recv(sock, nl_pid, seq, __dump_class_nlmsg,

			    dump_class_nlmsg, cookie);

}



static int __dump_qdisc_nlmsg(struct nlmsghdr *nlh,

			      dump_nlmsg_t dump_qdisc_nlmsg,

			      void *cookie)

{

	struct nlattr *tb[TCA_MAX + 1], *attr;

	struct tcmsg *t = NLMSG_DATA(nlh);

	int len;



	len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));

	attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));

	if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)

		return -LIBBPF_ERRNO__NLPARSE;



	return dump_qdisc_nlmsg(cookie, t, tb);

}



static int netlink_get_qdisc(int sock, unsigned int nl_pid, int ifindex,

			     dump_nlmsg_t dump_qdisc_nlmsg, void *cookie)

{

	struct {

		struct nlmsghdr nlh;

		struct tcmsg t;

	} req = {

		.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),

		.nlh.nlmsg_type = RTM_GETQDISC,

		.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,

		.t.tcm_family = AF_UNSPEC,

		.t.tcm_ifindex = ifindex,

	};

	int seq = time(NULL);



	req.nlh.nlmsg_seq = seq;

	if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)

		return -errno;



	return netlink_recv(sock, nl_pid, seq, __dump_qdisc_nlmsg,

			    dump_qdisc_nlmsg, cookie);

}



static int __dump_filter_nlmsg(struct nlmsghdr *nlh,

			       dump_nlmsg_t dump_filter_nlmsg,

			       void *cookie)

{

	struct nlattr *tb[TCA_MAX + 1], *attr;

	struct tcmsg *t = NLMSG_DATA(nlh);

	int len;



	len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));

	attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));

	if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)

		return -LIBBPF_ERRNO__NLPARSE;



	return dump_filter_nlmsg(cookie, t, tb);

}



static int netlink_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle,

			      dump_nlmsg_t dump_filter_nlmsg, void *cookie)

{

	struct {

		struct nlmsghdr nlh;

		struct tcmsg t;

	} req = {

		.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),

		.nlh.nlmsg_type = RTM_GETTFILTER,

		.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,

		.t.tcm_family = AF_UNSPEC,

		.t.tcm_ifindex = ifindex,

		.t.tcm_parent = handle,

	};

	int seq = time(NULL);



	req.nlh.nlmsg_seq = seq;

	if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)

		return -errno;



	return netlink_recv(sock, nl_pid, seq, __dump_filter_nlmsg,

			    dump_filter_nlmsg, cookie);

}



static int __dump_link_nlmsg(struct nlmsghdr *nlh,

			     dump_nlmsg_t dump_link_nlmsg, void *cookie)

{

	struct nlattr *tb[IFLA_MAX + 1], *attr;

	struct ifinfomsg *ifi = NLMSG_DATA(nlh);

	int len;



	len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*ifi));

	attr = (struct nlattr *) ((void *) ifi + NLMSG_ALIGN(sizeof(*ifi)));

	if (libbpf_nla_parse(tb, IFLA_MAX, attr, len, NULL) != 0)

		return -LIBBPF_ERRNO__NLPARSE;



	return dump_link_nlmsg(cookie, ifi, tb);

}



static int netlink_get_link(int sock, unsigned int nl_pid,

			    dump_nlmsg_t dump_link_nlmsg, void *cookie)

{

	struct {

		struct nlmsghdr nlh;

		struct ifinfomsg ifm;

	} req = {

		.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),

		.nlh.nlmsg_type = RTM_GETLINK,

		.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,

		.ifm.ifi_family = AF_PACKET,

	};

	int seq = time(NULL);



	req.nlh.nlmsg_seq = seq;

	if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)

		return -errno;



	return netlink_recv(sock, nl_pid, seq, __dump_link_nlmsg,

			    dump_link_nlmsg, cookie);

}



static int dump_link_nlmsg(void *cookie, void *msg, struct nlattr **tb)

{

	struct bpf_netdev_t *netinfo = cookie;
@@ -168,13 +433,13 @@ static int show_dev_tc_bpf(int sock, unsigned int nl_pid, 
	tcinfo.array_len = 0;



	tcinfo.is_qdisc = false;

	ret = libbpf_nl_get_class(sock, nl_pid, dev->ifindex,

	ret = netlink_get_class(sock, nl_pid, dev->ifindex,

				dump_class_qdisc_nlmsg, &tcinfo);

	if (ret)

		goto out;



	tcinfo.is_qdisc = true;

	ret = libbpf_nl_get_qdisc(sock, nl_pid, dev->ifindex,

	ret = netlink_get_qdisc(sock, nl_pid, dev->ifindex,

				dump_class_qdisc_nlmsg, &tcinfo);

	if (ret)

		goto out;
@@ -183,7 +448,7 @@ static int show_dev_tc_bpf(int sock, unsigned int nl_pid, 
	filter_info.ifindex = dev->ifindex;

	for (i = 0; i < tcinfo.used_len; i++) {

		filter_info.kind = tcinfo.handle_array[i].kind;

		ret = libbpf_nl_get_filter(sock, nl_pid, dev->ifindex,

		ret = netlink_get_filter(sock, nl_pid, dev->ifindex,

					 tcinfo.handle_array[i].handle,

					 dump_filter_nlmsg, &filter_info);

		if (ret)
@@ -193,21 +458,21 @@ static int show_dev_tc_bpf(int sock, unsigned int nl_pid, 
	/* root, ingress and egress handle */

	handle = TC_H_ROOT;

	filter_info.kind = "root";

	ret = libbpf_nl_get_filter(sock, nl_pid, dev->ifindex, handle,

	ret = netlink_get_filter(sock, nl_pid, dev->ifindex, handle,

				 dump_filter_nlmsg, &filter_info);

	if (ret)

		goto out;



	handle = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_INGRESS);

	filter_info.kind = "clsact/ingress";

	ret = libbpf_nl_get_filter(sock, nl_pid, dev->ifindex, handle,

	ret = netlink_get_filter(sock, nl_pid, dev->ifindex, handle,

				 dump_filter_nlmsg, &filter_info);

	if (ret)

		goto out;



	handle = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_EGRESS);

	filter_info.kind = "clsact/egress";

	ret = libbpf_nl_get_filter(sock, nl_pid, dev->ifindex, handle,

	ret = netlink_get_filter(sock, nl_pid, dev->ifindex, handle,

				 dump_filter_nlmsg, &filter_info);

	if (ret)

		goto out;
@@ -386,7 +651,7 @@ static int do_show(int argc, char **argv) 
	struct bpf_attach_info attach_info = {};

	int i, sock, ret, filter_idx = -1;

	struct bpf_netdev_t dev_array;

	unsigned int nl_pid;

	unsigned int nl_pid = 0;

	char err_buf[256];



	if (argc == 2) {
@@ -401,7 +666,7 @@ static int do_show(int argc, char **argv) 
	if (ret)

		return -1;



	sock = libbpf_netlink_open(&nl_pid);

	sock = netlink_open(&nl_pid);

	if (sock < 0) {

		fprintf(stderr, "failed to open netlink sock\n");

		return -1;
@@ -416,7 +681,7 @@ static int do_show(int argc, char **argv) 
		jsonw_start_array(json_wtr);

	NET_START_OBJECT;

	NET_START_ARRAY("xdp", "%s:\n");

	ret = libbpf_nl_get_link(sock, nl_pid, dump_link_nlmsg, &dev_array);

	ret = netlink_get_link(sock, nl_pid, dump_link_nlmsg, &dev_array);

	NET_END_ARRAY("\n");



	if (!ret) {

tools/build/Makefile.feature

+0 −1
Original line number Diff line number Diff line
@@ -46,7 +46,6 @@ FEATURE_TESTS_BASIC := \ 
        libelf-getphdrnum               \

        libelf-gelf_getnote             \

        libelf-getshdrstrndx            \

        libelf-mmap                     \

        libnuma                         \

        numa_num_possible_cpus          \

        libperl                         \

tools/build/feature/Makefile

+0 −4
Original line number Diff line number Diff line
@@ -25,7 +25,6 @@ FILES= \ 
         test-libelf-getphdrnum.bin             \

         test-libelf-gelf_getnote.bin           \

         test-libelf-getshdrstrndx.bin          \

         test-libelf-mmap.bin                   \

         test-libdebuginfod.bin                 \

         test-libnuma.bin                       \

         test-numa_num_possible_cpus.bin        \
@@ -146,9 +145,6 @@ $(OUTPUT)test-dwarf.bin: 
$(OUTPUT)test-dwarf_getlocations.bin:

	$(BUILD) $(DWARFLIBS)



$(OUTPUT)test-libelf-mmap.bin:

	$(BUILD) -lelf



$(OUTPUT)test-libelf-getphdrnum.bin:

	$(BUILD) -lelf

tools/build/feature/test-all.c

+0 −4
Original line number Diff line number Diff line
@@ -30,10 +30,6 @@ 
# include "test-libelf.c"

#undef main



#define main main_test_libelf_mmap

# include "test-libelf-mmap.c"

#undef main



#define main main_test_get_current_dir_name

# include "test-get_current_dir_name.c"

#undef main

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