// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)

/*
 * common eBPF ELF operations.
 *
 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
 * Copyright (C) 2015 Huawei Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License (not later!)
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program; if not,  see <http://www.gnu.org/licenses>
 */

#include <stdlib.h>
#include <string.h>
#include <memory.h>
#include <unistd.h>
#include <asm/unistd.h>
#include <errno.h>
#include <linux/bpf.h>
#include "bpf.h"
#include "libbpf.h"
#include "libbpf_internal.h"

/*
 * When building perf, unistd.h is overridden. __NR_bpf is
 * required to be defined explicitly.
 */
#ifndef __NR_bpf
# if defined(__i386__)
#  define __NR_bpf 357
# elif defined(__x86_64__)
#  define __NR_bpf 321
# elif defined(__aarch64__)
#  define __NR_bpf 280
# elif defined(__sparc__)
#  define __NR_bpf 349
# elif defined(__s390__)
#  define __NR_bpf 351
# elif defined(__arc__)
#  define __NR_bpf 280
# else
#  error __NR_bpf not defined. libbpf does not support your arch.
# endif
#endif

static inline __u64 ptr_to_u64(const void *ptr)
{
        return (__u64) (unsigned long) ptr;
}

static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
                          unsigned int size)
{
        return syscall(__NR_bpf, cmd, attr, size);
}

static inline int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size)
{
        int fd;

        do {
                fd = sys_bpf(BPF_PROG_LOAD, attr, size);
        } while (fd < 0 && errno == EAGAIN);

        return fd;
}

int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr)
{
        union bpf_attr attr;

        memset(&attr, '\0', sizeof(attr));

        attr.map_type = create_attr->map_type;
        attr.key_size = create_attr->key_size;
        attr.value_size = create_attr->value_size;
        attr.max_entries = create_attr->max_entries;
        attr.map_flags = create_attr->map_flags;
        if (create_attr->name)
                memcpy(attr.map_name, create_attr->name,
                       min(strlen(create_attr->name), BPF_OBJ_NAME_LEN - 1));
        attr.numa_node = create_attr->numa_node;
        attr.btf_fd = create_attr->btf_fd;
        attr.btf_key_type_id = create_attr->btf_key_type_id;
        attr.btf_value_type_id = create_attr->btf_value_type_id;
        attr.map_ifindex = create_attr->map_ifindex;
        attr.inner_map_fd = create_attr->inner_map_fd;

        return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
}

int bpf_create_map_node(enum bpf_map_type map_type, const char *name,
                        int key_size, int value_size, int max_entries,
                        __u32 map_flags, int node)
{
        struct bpf_create_map_attr map_attr = {};

        map_attr.name = name;
        map_attr.map_type = map_type;
        map_attr.map_flags = map_flags;
        map_attr.key_size = key_size;
        map_attr.value_size = value_size;
        map_attr.max_entries = max_entries;
        if (node >= 0) {
                map_attr.numa_node = node;
                map_attr.map_flags |= BPF_F_NUMA_NODE;
        }

        return bpf_create_map_xattr(&map_attr);
}

int bpf_create_map(enum bpf_map_type map_type, int key_size,
                   int value_size, int max_entries, __u32 map_flags)
{
        struct bpf_create_map_attr map_attr = {};

        map_attr.map_type = map_type;
        map_attr.map_flags = map_flags;
        map_attr.key_size = key_size;
        map_attr.value_size = value_size;
        map_attr.max_entries = max_entries;

        return bpf_create_map_xattr(&map_attr);
}

int bpf_create_map_name(enum bpf_map_type map_type, const char *name,
                        int key_size, int value_size, int max_entries,
                        __u32 map_flags)
{
        struct bpf_create_map_attr map_attr = {};

        map_attr.name = name;
        map_attr.map_type = map_type;
        map_attr.map_flags = map_flags;
        map_attr.key_size = key_size;
        map_attr.value_size = value_size;
        map_attr.max_entries = max_entries;

        return bpf_create_map_xattr(&map_attr);
}

int bpf_create_map_in_map_node(enum bpf_map_type map_type, const char *name,
                               int key_size, int inner_map_fd, int max_entries,
                               __u32 map_flags, int node)
{
        union bpf_attr attr;

        memset(&attr, '\0', sizeof(attr));

        attr.map_type = map_type;
        attr.key_size = key_size;
        attr.value_size = 4;
        attr.inner_map_fd = inner_map_fd;
        attr.max_entries = max_entries;
        attr.map_flags = map_flags;
        if (name)
                memcpy(attr.map_name, name,
                       min(strlen(name), BPF_OBJ_NAME_LEN - 1));

        if (node >= 0) {
                attr.map_flags |= BPF_F_NUMA_NODE;
                attr.numa_node = node;
        }

        return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
}

int bpf_create_map_in_map(enum bpf_map_type map_type, const char *name,
                          int key_size, int inner_map_fd, int max_entries,
                          __u32 map_flags)
{
        return bpf_create_map_in_map_node(map_type, name, key_size,
                                          inner_map_fd, max_entries, map_flags,
                                          -1);
}

static void *
alloc_zero_tailing_info(const void *orecord, __u32 cnt,
                        __u32 actual_rec_size, __u32 expected_rec_size)
{
        __u64 info_len = actual_rec_size * cnt;
        void *info, *nrecord;
        int i;

        info = malloc(info_len);
        if (!info)
                return NULL;

        /* zero out bytes kernel does not understand */
        nrecord = info;
        for (i = 0; i < cnt; i++) {
                memcpy(nrecord, orecord, expected_rec_size);
                memset(nrecord + expected_rec_size, 0,
                       actual_rec_size - expected_rec_size);
                orecord += actual_rec_size;
                nrecord += actual_rec_size;
        }

        return info;
}

int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
                           char *log_buf, size_t log_buf_sz)
{
        void *finfo = NULL, *linfo = NULL;
        union bpf_attr attr;
        __u32 log_level;
        int fd;

        if (!load_attr || !log_buf != !log_buf_sz)
                return -EINVAL;

        log_level = load_attr->log_level;
        if (log_level > (4 | 2 | 1) || (log_level && !log_buf))
                return -EINVAL;

        memset(&attr, 0, sizeof(attr));
        attr.prog_type = load_attr->prog_type;
        attr.expected_attach_type = load_attr->expected_attach_type;
        attr.insn_cnt = (__u32)load_attr->insns_cnt;
        attr.insns = ptr_to_u64(load_attr->insns);
        attr.license = ptr_to_u64(load_attr->license);

        attr.log_level = log_level;
        if (log_level) {
                attr.log_buf = ptr_to_u64(log_buf);
                attr.log_size = log_buf_sz;
        } else {
                attr.log_buf = ptr_to_u64(NULL);
                attr.log_size = 0;
        }

        attr.kern_version = load_attr->kern_version;
        attr.prog_ifindex = load_attr->prog_ifindex;
        attr.prog_btf_fd = load_attr->prog_btf_fd;
        attr.func_info_rec_size = load_attr->func_info_rec_size;
        attr.func_info_cnt = load_attr->func_info_cnt;
        attr.func_info = ptr_to_u64(load_attr->func_info);
        attr.line_info_rec_size = load_attr->line_info_rec_size;
        attr.line_info_cnt = load_attr->line_info_cnt;
        attr.line_info = ptr_to_u64(load_attr->line_info);
        if (load_attr->name)
                memcpy(attr.prog_name, load_attr->name,
                       min(strlen(load_attr->name), BPF_OBJ_NAME_LEN - 1));
        attr.prog_flags = load_attr->prog_flags;

        fd = sys_bpf_prog_load(&attr, sizeof(attr));
        if (fd >= 0)
                return fd;

        /* After bpf_prog_load, the kernel may modify certain attributes
         * to give user space a hint how to deal with loading failure.
         * Check to see whether we can make some changes and load again.
         */
        while (errno == E2BIG && (!finfo || !linfo)) {
                if (!finfo && attr.func_info_cnt &&
                    attr.func_info_rec_size < load_attr->func_info_rec_size) {
                        /* try with corrected func info records */
                        finfo = alloc_zero_tailing_info(load_attr->func_info,
                                                        load_attr->func_info_cnt,
                                                        load_attr->func_info_rec_size,
                                                        attr.func_info_rec_size);
                        if (!finfo)
                                goto done;

                        attr.func_info = ptr_to_u64(finfo);
                        attr.func_info_rec_size = load_attr->func_info_rec_size;
                } else if (!linfo && attr.line_info_cnt &&
                           attr.line_info_rec_size <
                           load_attr->line_info_rec_size) {
                        linfo = alloc_zero_tailing_info(load_attr->line_info,
                                                        load_attr->line_info_cnt,
                                                        load_attr->line_info_rec_size,
                                                        attr.line_info_rec_size);
                        if (!linfo)
                                goto done;

                        attr.line_info = ptr_to_u64(linfo);
                        attr.line_info_rec_size = load_attr->line_info_rec_size;
                } else {
                        break;
                }

                fd = sys_bpf_prog_load(&attr, sizeof(attr));

                if (fd >= 0)
                        goto done;
        }

        if (log_level || !log_buf)
                goto done;

        /* Try again with log */
        attr.log_buf = ptr_to_u64(log_buf);
        attr.log_size = log_buf_sz;
        attr.log_level = 1;
        log_buf[0] = 0;
        fd = sys_bpf_prog_load(&attr, sizeof(attr));
done:
        free(finfo);
        free(linfo);
        return fd;
}

int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
                     size_t insns_cnt, const char *license,
                     __u32 kern_version, char *log_buf,
                     size_t log_buf_sz)
{
        struct bpf_load_program_attr load_attr;

        memset(&load_attr, 0, sizeof(struct bpf_load_program_attr));
        load_attr.prog_type = type;
        load_attr.expected_attach_type = 0;
        load_attr.name = NULL;
        load_attr.insns = insns;
        load_attr.insns_cnt = insns_cnt;
        load_attr.license = license;
        load_attr.kern_version = kern_version;

        return bpf_load_program_xattr(&load_attr, log_buf, log_buf_sz);
}

int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns,
                       size_t insns_cnt, __u32 prog_flags, const char *license,
                       __u32 kern_version, char *log_buf, size_t log_buf_sz,
                       int log_level)
{
        union bpf_attr attr;

        memset(&attr, 0, sizeof(attr));
        attr.prog_type = type;
        attr.insn_cnt = (__u32)insns_cnt;
        attr.insns = ptr_to_u64(insns);
        attr.license = ptr_to_u64(license);
        attr.log_buf = ptr_to_u64(log_buf);
        attr.log_size = log_buf_sz;
        attr.log_level = log_level;
        log_buf[0] = 0;
        attr.kern_version = kern_version;
        attr.prog_flags = prog_flags;

        return sys_bpf_prog_load(&attr, sizeof(attr));
}

int bpf_map_update_elem(int fd, const void *key, const void *value,
                        __u64 flags)
{
        union bpf_attr attr;

        memset(&attr, 0, sizeof(attr));
        attr.map_fd = fd;
        attr.key = ptr_to_u64(key);
        attr.value = ptr_to_u64(value);
        attr.flags = flags;

        return sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
}

int bpf_map_lookup_elem(int fd, const void *key, void *value)
{
        union bpf_attr attr;

        memset(&attr, 0, sizeof(attr));
        attr.map_fd = fd;
        attr.key = ptr_to_u64(key);
        attr.value = ptr_to_u64(value);

        return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
}

int bpf_map_lookup_elem_flags(int fd, const void *key, void *value, __u64 flags)
{
        union bpf_attr attr;

        memset(&attr, 0, sizeof(attr));
        attr.map_fd = fd;
        attr.key = ptr_to_u64(key);
        attr.value = ptr_to_u64(value);
        attr.flags = flags;

        return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
}

int bpf_map_lookup_and_delete_elem(int fd, const void *key, void *value)
{
        union bpf_attr attr;

        memset(&attr, 0, sizeof(attr));
        attr.map_fd = fd;
        attr.key = ptr_to_u64(key);
        attr.value = ptr_to_u64(value);

        return sys_bpf(BPF_MAP_LOOKUP_AND_DELETE_ELEM, &attr, sizeof(attr));
}

int bpf_map_delete_elem(int fd, const void *key)
{
        union bpf_attr attr;

        memset(&attr, 0, sizeof(attr));
        attr.map_fd = fd;
        attr.key = ptr_to_u64(key);

        return sys_bpf(BPF_MAP_DELETE_ELEM, &attr, sizeof(attr));
}

int bpf_map_get_next_key(int fd, const void *key, void *next_key)
{
        union bpf_attr attr;

        memset(&attr, 0, sizeof(attr));
        attr.map_fd = fd;
        attr.key = ptr_to_u64(key);
        attr.next_key = ptr_to_u64(next_key);

        return sys_bpf(BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr));
}

int bpf_map_freeze(int fd)
{
        union bpf_attr attr;

        memset(&attr, 0, sizeof(attr));
        attr.map_fd = fd;

        return sys_bpf(BPF_MAP_FREEZE, &attr, sizeof(attr));
}

int bpf_obj_pin(int fd, const char *pathname)
{
        union bpf_attr attr;

        memset(&attr, 0, sizeof(attr));
        attr.pathname = ptr_to_u64((void *)pathname);
        attr.bpf_fd = fd;

        return sys_bpf(BPF_OBJ_PIN, &attr, sizeof(attr));
}

int bpf_obj_get(const char *pathname)
{
        union bpf_attr attr;

        memset(&attr, 0, sizeof(attr));
        attr.pathname = ptr_to_u64((void *)pathname);

        return sys_bpf(BPF_OBJ_GET, &attr, sizeof(attr));
}

int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type,
                    unsigned int flags)
{
        union bpf_attr attr;

        memset(&attr, 0, sizeof(attr));
        attr.target_fd     = target_fd;
        attr.attach_bpf_fd = prog_fd;
        attr.attach_type   = type;
        attr.attach_flags  = flags;

        return sys_bpf(BPF_PROG_ATTACH, &attr, sizeof(attr));
}

int bpf_prog_detach(int target_fd, enum bpf_attach_type type)
{
        union bpf_attr attr;

        memset(&attr, 0, sizeof(attr));
        attr.target_fd   = target_fd;
        attr.attach_type = type;

        return sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr));
}

int bpf_prog_detach2(int prog_fd, int target_fd, enum bpf_attach_type type)
{
        union bpf_attr attr;

        memset(&attr, 0, sizeof(attr));
        attr.target_fd   = target_fd;
        attr.attach_bpf_fd = prog_fd;
        attr.attach_type = type;

        return sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr));
}

int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags,
                   __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt)
{
        union bpf_attr attr;
        int ret;

        memset(&attr, 0, sizeof(attr));
        attr.query.target_fd    = target_fd;
        attr.query.attach_type  = type;
        attr.query.query_flags  = query_flags;
        attr.query.prog_cnt     = *prog_cnt;
        attr.query.prog_ids     = ptr_to_u64(prog_ids);

        ret = sys_bpf(BPF_PROG_QUERY, &attr, sizeof(attr));
        if (attach_flags)
                *attach_flags = attr.query.attach_flags;
        *prog_cnt = attr.query.prog_cnt;
        return ret;
}

int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size,
                      void *data_out, __u32 *size_out, __u32 *retval,
                      __u32 *duration)
{
        union bpf_attr attr;
        int ret;

        memset(&attr, 0, sizeof(attr));
        attr.test.prog_fd = prog_fd;
        attr.test.data_in = ptr_to_u64(data);
        attr.test.data_out = ptr_to_u64(data_out);
        attr.test.data_size_in = size;
        attr.test.repeat = repeat;

        ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr));
        if (size_out)
                *size_out = attr.test.data_size_out;
        if (retval)
                *retval = attr.test.retval;
        if (duration)
                *duration = attr.test.duration;
        return ret;
}

int bpf_prog_test_run_xattr(struct bpf_prog_test_run_attr *test_attr)
{
        union bpf_attr attr;
        int ret;

        if (!test_attr->data_out && test_attr->data_size_out > 0)
                return -EINVAL;

        memset(&attr, 0, sizeof(attr));
        attr.test.prog_fd = test_attr->prog_fd;
        attr.test.data_in = ptr_to_u64(test_attr->data_in);
        attr.test.data_out = ptr_to_u64(test_attr->data_out);
        attr.test.data_size_in = test_attr->data_size_in;
        attr.test.data_size_out = test_attr->data_size_out;
        attr.test.ctx_in = ptr_to_u64(test_attr->ctx_in);
        attr.test.ctx_out = ptr_to_u64(test_attr->ctx_out);
        attr.test.ctx_size_in = test_attr->ctx_size_in;
        attr.test.ctx_size_out = test_attr->ctx_size_out;
        attr.test.repeat = test_attr->repeat;

        ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr));
        test_attr->data_size_out = attr.test.data_size_out;
        test_attr->ctx_size_out = attr.test.ctx_size_out;
        test_attr->retval = attr.test.retval;
        test_attr->duration = attr.test.duration;
        return ret;
}

static int bpf_obj_get_next_id(__u32 start_id, __u32 *next_id, int cmd)
{
        union bpf_attr attr;
        int err;

        memset(&attr, 0, sizeof(attr));
        attr.start_id = start_id;

        err = sys_bpf(cmd, &attr, sizeof(attr));
        if (!err)
                *next_id = attr.next_id;

        return err;
}

int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id)
{
        return bpf_obj_get_next_id(start_id, next_id, BPF_PROG_GET_NEXT_ID);
}

int bpf_map_get_next_id(__u32 start_id, __u32 *next_id)
{
        return bpf_obj_get_next_id(start_id, next_id, BPF_MAP_GET_NEXT_ID);
}

int bpf_btf_get_next_id(__u32 start_id, __u32 *next_id)
{
        return bpf_obj_get_next_id(start_id, next_id, BPF_BTF_GET_NEXT_ID);
}

int bpf_prog_get_fd_by_id(__u32 id)
{
        union bpf_attr attr;

        memset(&attr, 0, sizeof(attr));
        attr.prog_id = id;

        return sys_bpf(BPF_PROG_GET_FD_BY_ID, &attr, sizeof(attr));
}

int bpf_map_get_fd_by_id(__u32 id)
{
        union bpf_attr attr;

        memset(&attr, 0, sizeof(attr));
        attr.map_id = id;

        return sys_bpf(BPF_MAP_GET_FD_BY_ID, &attr, sizeof(attr));
}

int bpf_btf_get_fd_by_id(__u32 id)
{
        union bpf_attr attr;

        memset(&attr, 0, sizeof(attr));
        attr.btf_id = id;

        return sys_bpf(BPF_BTF_GET_FD_BY_ID, &attr, sizeof(attr));
}

int bpf_obj_get_info_by_fd(int prog_fd, void *info, __u32 *info_len)
{
        union bpf_attr attr;
        int err;

        memset(&attr, 0, sizeof(attr));
        attr.info.bpf_fd = prog_fd;
        attr.info.info_len = *info_len;
        attr.info.info = ptr_to_u64(info);

        err = sys_bpf(BPF_OBJ_GET_INFO_BY_FD, &attr, sizeof(attr));
        if (!err)
                *info_len = attr.info.info_len;

        return err;
}

int bpf_raw_tracepoint_open(const char *name, int prog_fd)
{
        union bpf_attr attr;

        memset(&attr, 0, sizeof(attr));
        attr.raw_tracepoint.name = ptr_to_u64(name);
        attr.raw_tracepoint.prog_fd = prog_fd;

        return sys_bpf(BPF_RAW_TRACEPOINT_OPEN, &attr, sizeof(attr));
}

int bpf_load_btf(void *btf, __u32 btf_size, char *log_buf, __u32 log_buf_size,
                 bool do_log)
{
        union bpf_attr attr = {};
        int fd;

        attr.btf = ptr_to_u64(btf);
        attr.btf_size = btf_size;

retry:
        if (do_log && log_buf && log_buf_size) {
                attr.btf_log_level = 1;
                attr.btf_log_size = log_buf_size;
                attr.btf_log_buf = ptr_to_u64(log_buf);
        }

        fd = sys_bpf(BPF_BTF_LOAD, &attr, sizeof(attr));
        if (fd == -1 && !do_log && log_buf && log_buf_size) {
                do_log = true;
                goto retry;
        }

        return fd;
}

int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf, __u32 *buf_len,
                      __u32 *prog_id, __u32 *fd_type, __u64 *probe_offset,
                      __u64 *probe_addr)
{
        union bpf_attr attr = {};
        int err;

        attr.task_fd_query.pid = pid;
        attr.task_fd_query.fd = fd;
        attr.task_fd_query.flags = flags;
        attr.task_fd_query.buf = ptr_to_u64(buf);
        attr.task_fd_query.buf_len = *buf_len;

        err = sys_bpf(BPF_TASK_FD_QUERY, &attr, sizeof(attr));
        *buf_len = attr.task_fd_query.buf_len;
        *prog_id = attr.task_fd_query.prog_id;
        *fd_type = attr.task_fd_query.fd_type;
        *probe_offset = attr.task_fd_query.probe_offset;
        *probe_addr = attr.task_fd_query.probe_addr;

        return err;
}