// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
/* Copyright (C) 2017-2018 Netronome Systems, Inc. */

#include <ctype.h>
#include <errno.h>
#include <getopt.h>
#include <linux/bpf.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <bpf/bpf.h>
#include <bpf/btf.h>
#include <bpf/hashmap.h>
#include <bpf/libbpf.h>

#include "main.h"

#define BATCH_LINE_LEN_MAX 65536
#define BATCH_ARG_NB_MAX 4096

const char *bin_name;
static int last_argc;
static char **last_argv;
static int (*last_do_help)(int argc, char **argv);
json_writer_t *json_wtr;
bool pretty_output;
bool json_output;
bool show_pinned;
bool block_mount;
bool verifier_logs;
bool relaxed_maps;
bool use_loader;
struct btf *base_btf;
struct hashmap *refs_table;
bool sign_progs;
const char *private_key_path;
const char *cert_path;

static void __noreturn clean_and_exit(int i)
{
        if (json_output)
                jsonw_destroy(&json_wtr);

        exit(i);
}

void usage(void)
{
        last_do_help(last_argc - 1, last_argv + 1);

        clean_and_exit(-1);
}

static int do_help(int argc, char **argv)
{
        if (json_output) {
                jsonw_null(json_wtr);
                return 0;
        }

        fprintf(stderr,
                "Usage: %s [OPTIONS] OBJECT { COMMAND | help }\n"
                "       %s batch file FILE\n"
                "       %s version\n"
                "\n"
                "       OBJECT := { prog | map | link | cgroup | perf | net | feature | btf | gen | struct_ops | iter | token }\n"
                "       " HELP_SPEC_OPTIONS " |\n"
                "                    {-V|--version} }\n"
                "",
                bin_name, bin_name, bin_name);

        return 0;
}

static int do_batch(int argc, char **argv);
static int do_version(int argc, char **argv);

static const struct cmd commands[] = {
        { "help",       do_help },
        { "batch",      do_batch },
        { "prog",       do_prog },
        { "map",        do_map },
        { "link",       do_link },
        { "cgroup",     do_cgroup },
        { "perf",       do_perf },
        { "net",        do_net },
        { "feature",    do_feature },
        { "btf",        do_btf },
        { "gen",        do_gen },
        { "struct_ops", do_struct_ops },
        { "iter",       do_iter },
        { "token",      do_token },
        { "version",    do_version },
        { 0 }
};

#ifndef BPFTOOL_VERSION
/* bpftool's major and minor version numbers are aligned on libbpf's. There is
 * an offset of 6 for the version number, because bpftool's version was higher
 * than libbpf's when we adopted this scheme. The patch number remains at 0
 * for now. Set BPFTOOL_VERSION to override.
 */
#define BPFTOOL_MAJOR_VERSION (LIBBPF_MAJOR_VERSION + 6)
#define BPFTOOL_MINOR_VERSION LIBBPF_MINOR_VERSION
#define BPFTOOL_PATCH_VERSION 0
#endif

static void
print_feature(const char *feature, bool state, unsigned int *nb_features)
{
        if (state) {
                printf("%s %s", *nb_features ? "," : "", feature);
                *nb_features = *nb_features + 1;
        }
}

static int do_version(int argc, char **argv)
{
#ifdef HAVE_LIBBFD_SUPPORT
        const bool has_libbfd = true;
#else
        const bool has_libbfd = false;
#endif
#ifdef HAVE_LLVM_SUPPORT
        const bool has_llvm = true;
#else
        const bool has_llvm = false;
#endif
#ifdef BPFTOOL_WITHOUT_SKELETONS
        const bool has_skeletons = false;
#else
        const bool has_skeletons = true;
#endif
        bool bootstrap = false;
        int i;

        for (i = 0; commands[i].cmd; i++) {
                if (!strcmp(commands[i].cmd, "prog")) {
                        /* Assume we run a bootstrap version if "bpftool prog"
                         * is not available.
                         */
                        bootstrap = !commands[i].func;
                        break;
                }
        }

        if (json_output) {
                jsonw_start_object(json_wtr);   /* root object */

                jsonw_name(json_wtr, "version");
#ifdef BPFTOOL_VERSION
                jsonw_printf(json_wtr, "\"%s\"", BPFTOOL_VERSION);
#else
                jsonw_printf(json_wtr, "\"%d.%d.%d\"", BPFTOOL_MAJOR_VERSION,
                             BPFTOOL_MINOR_VERSION, BPFTOOL_PATCH_VERSION);
#endif
                jsonw_name(json_wtr, "libbpf_version");
                jsonw_printf(json_wtr, "\"%u.%u\"",
                             libbpf_major_version(), libbpf_minor_version());

                jsonw_name(json_wtr, "features");
                jsonw_start_object(json_wtr);   /* features */
                jsonw_bool_field(json_wtr, "libbfd", has_libbfd);
                jsonw_bool_field(json_wtr, "llvm", has_llvm);
                jsonw_bool_field(json_wtr, "skeletons", has_skeletons);
                jsonw_bool_field(json_wtr, "bootstrap", bootstrap);
                jsonw_end_object(json_wtr);     /* features */

                jsonw_end_object(json_wtr);     /* root object */
        } else {
                unsigned int nb_features = 0;

#ifdef BPFTOOL_VERSION
                printf("%s v%s\n", bin_name, BPFTOOL_VERSION);
#else
                printf("%s v%d.%d.%d\n", bin_name, BPFTOOL_MAJOR_VERSION,
                       BPFTOOL_MINOR_VERSION, BPFTOOL_PATCH_VERSION);
#endif
                printf("using libbpf %s\n", libbpf_version_string());
                printf("features:");
                print_feature("libbfd", has_libbfd, &nb_features);
                print_feature("llvm", has_llvm, &nb_features);
                print_feature("skeletons", has_skeletons, &nb_features);
                print_feature("bootstrap", bootstrap, &nb_features);
                printf("\n");
        }
        return 0;
}

int cmd_select(const struct cmd *cmds, int argc, char **argv,
               int (*help)(int argc, char **argv))
{
        unsigned int i;

        last_argc = argc;
        last_argv = argv;
        last_do_help = help;

        if (argc < 1 && cmds[0].func)
                return cmds[0].func(argc, argv);

        for (i = 0; cmds[i].cmd; i++) {
                if (is_prefix(*argv, cmds[i].cmd)) {
                        if (!cmds[i].func) {
                                p_err("command '%s' is not supported in bootstrap mode",
                                      cmds[i].cmd);
                                return -1;
                        }
                        return cmds[i].func(argc - 1, argv + 1);
                }
        }

        help(argc - 1, argv + 1);

        return -1;
}

bool is_prefix(const char *pfx, const char *str)
{
        if (!pfx)
                return false;
        if (strlen(str) < strlen(pfx))
                return false;

        return !memcmp(str, pfx, strlen(pfx));
}

/* Last argument MUST be NULL pointer */
int detect_common_prefix(const char *arg, ...)
{
        unsigned int count = 0;
        const char *ref;
        char msg[256];
        va_list ap;

        snprintf(msg, sizeof(msg), "ambiguous prefix: '%s' could be '", arg);
        va_start(ap, arg);
        while ((ref = va_arg(ap, const char *))) {
                if (!is_prefix(arg, ref))
                        continue;
                count++;
                if (count > 1)
                        strncat(msg, "' or '", sizeof(msg) - strlen(msg) - 1);
                strncat(msg, ref, sizeof(msg) - strlen(msg) - 1);
        }
        va_end(ap);
        strncat(msg, "'", sizeof(msg) - strlen(msg) - 1);

        if (count >= 2) {
                p_err("%s", msg);
                return -1;
        }

        return 0;
}

void fprint_hex(FILE *f, void *arg, unsigned int n, const char *sep)
{
        unsigned char *data = arg;
        unsigned int i;

        for (i = 0; i < n; i++) {
                const char *pfx = "";

                if (!i)
                        /* nothing */;
                else if (!(i % 16))
                        fprintf(f, "\n");
                else if (!(i % 8))
                        fprintf(f, "  ");
                else
                        pfx = sep;

                fprintf(f, "%s%02hhx", i ? pfx : "", data[i]);
        }
}

/* Split command line into argument vector. */
static int make_args(char *line, char *n_argv[], int maxargs, int cmd_nb)
{
        static const char ws[] = " \t\r\n";
        char *cp = line;
        int n_argc = 0;

        while (*cp) {
                /* Skip leading whitespace. */
                cp += strspn(cp, ws);

                if (*cp == '\0')
                        break;

                if (n_argc >= (maxargs - 1)) {
                        p_err("too many arguments to command %d", cmd_nb);
                        return -1;
                }

                /* Word begins with quote. */
                if (*cp == '\'' || *cp == '"') {
                        char quote = *cp++;

                        n_argv[n_argc++] = cp;
                        /* Find ending quote. */
                        cp = strchr(cp, quote);
                        if (!cp) {
                                p_err("unterminated quoted string in command %d",
                                      cmd_nb);
                                return -1;
                        }
                } else {
                        n_argv[n_argc++] = cp;

                        /* Find end of word. */
                        cp += strcspn(cp, ws);
                        if (*cp == '\0')
                                break;
                }

                /* Separate words. */
                *cp++ = 0;
        }
        n_argv[n_argc] = NULL;

        return n_argc;
}

static int do_batch(int argc, char **argv)
{
        char buf[BATCH_LINE_LEN_MAX], contline[BATCH_LINE_LEN_MAX];
        char *n_argv[BATCH_ARG_NB_MAX];
        unsigned int lines = 0;
        int n_argc;
        FILE *fp;
        char *cp;
        int err = 0;
        int i;

        if (argc < 2) {
                p_err("too few parameters for batch");
                return -1;
        } else if (argc > 2) {
                p_err("too many parameters for batch");
                return -1;
        } else if (!is_prefix(*argv, "file")) {
                p_err("expected 'file', got: %s", *argv);
                return -1;
        }
        NEXT_ARG();

        if (!strcmp(*argv, "-"))
                fp = stdin;
        else
                fp = fopen(*argv, "r");
        if (!fp) {
                p_err("Can't open file (%s): %s", *argv, strerror(errno));
                return -1;
        }

        if (json_output)
                jsonw_start_array(json_wtr);
        while (fgets(buf, sizeof(buf), fp)) {
                cp = strchr(buf, '#');
                if (cp)
                        *cp = '\0';

                if (strlen(buf) == sizeof(buf) - 1) {
                        errno = E2BIG;
                        break;
                }

                /* Append continuation lines if any (coming after a line ending
                 * with '\' in the batch file).
                 */
                while ((cp = strstr(buf, "\\\n")) != NULL) {
                        if (!fgets(contline, sizeof(contline), fp) ||
                            strlen(contline) == 0) {
                                p_err("missing continuation line on command %u",
                                      lines);
                                err = -1;
                                goto err_close;
                        }

                        cp = strchr(contline, '#');
                        if (cp)
                                *cp = '\0';

                        if (strlen(buf) + strlen(contline) + 1 > sizeof(buf)) {
                                p_err("command %u is too long", lines);
                                err = -1;
                                goto err_close;
                        }
                        buf[strlen(buf) - 2] = '\0';
                        strcat(buf, contline);
                }

                n_argc = make_args(buf, n_argv, BATCH_ARG_NB_MAX, lines);
                if (!n_argc)
                        continue;
                if (n_argc < 0) {
                        err = n_argc;
                        goto err_close;
                }

                if (json_output) {
                        jsonw_start_object(json_wtr);
                        jsonw_name(json_wtr, "command");
                        jsonw_start_array(json_wtr);
                        for (i = 0; i < n_argc; i++)
                                jsonw_string(json_wtr, n_argv[i]);
                        jsonw_end_array(json_wtr);
                        jsonw_name(json_wtr, "output");
                }

                err = cmd_select(commands, n_argc, n_argv, do_help);

                if (json_output)
                        jsonw_end_object(json_wtr);

                if (err)
                        goto err_close;

                lines++;
        }

        if (errno && errno != ENOENT) {
                p_err("reading batch file failed: %s", strerror(errno));
                err = -1;
        } else {
                if (!json_output)
                        printf("processed %u commands\n", lines);
        }
err_close:
        if (fp != stdin)
                fclose(fp);

        if (json_output)
                jsonw_end_array(json_wtr);

        return err;
}

int main(int argc, char **argv)
{
        static const struct option options[] = {
                { "json",       no_argument,    NULL,   'j' },
                { "help",       no_argument,    NULL,   'h' },
                { "pretty",     no_argument,    NULL,   'p' },
                { "version",    no_argument,    NULL,   'V' },
                { "bpffs",      no_argument,    NULL,   'f' },
                { "mapcompat",  no_argument,    NULL,   'm' },
                { "nomount",    no_argument,    NULL,   'n' },
                { "debug",      no_argument,    NULL,   'd' },
                { "use-loader", no_argument,    NULL,   'L' },
                { "sign",       no_argument,    NULL,   'S' },
                { "base-btf",   required_argument, NULL, 'B' },
                { 0 }
        };
        bool version_requested = false;
        int opt, ret;

        setlinebuf(stdout);

#ifdef USE_LIBCAP
        /* Libcap < 2.63 hooks before main() to compute the number of
         * capabilities of the running kernel, and doing so it calls prctl()
         * which may fail and set errno to non-zero.
         * Let's reset errno to make sure this does not interfere with the
         * batch mode.
         */
        errno = 0;
#endif

        last_do_help = do_help;
        pretty_output = false;
        json_output = false;
        show_pinned = false;
        block_mount = false;
        bin_name = "bpftool";

        opterr = 0;
        while ((opt = getopt_long(argc, argv, "VhpjfLmndSi:k:B:l",
                                  options, NULL)) >= 0) {
                switch (opt) {
                case 'V':
                        version_requested = true;
                        break;
                case 'h':
                        return do_help(argc, argv);
                case 'p':
                        pretty_output = true;
                        /* fall through */
                case 'j':
                        if (!json_output) {
                                json_wtr = jsonw_new(stdout);
                                if (!json_wtr) {
                                        p_err("failed to create JSON writer");
                                        return -1;
                                }
                                json_output = true;
                        }
                        jsonw_pretty(json_wtr, pretty_output);
                        break;
                case 'f':
                        show_pinned = true;
                        break;
                case 'm':
                        relaxed_maps = true;
                        break;
                case 'n':
                        block_mount = true;
                        break;
                case 'd':
                        libbpf_set_print(print_all_levels);
                        verifier_logs = true;
                        break;
                case 'B':
                        base_btf = btf__parse(optarg, NULL);
                        if (!base_btf) {
                                p_err("failed to parse base BTF at '%s': %d\n",
                                      optarg, -errno);
                                return -1;
                        }
                        break;
                case 'L':
                        use_loader = true;
                        break;
                case 'S':
                        sign_progs = true;
                        use_loader = true;
                        break;
                case 'k':
                        private_key_path = optarg;
                        break;
                case 'i':
                        cert_path = optarg;
                        break;
                default:
                        p_err("unrecognized option '%s'", argv[optind - 1]);
                        if (json_output)
                                clean_and_exit(-1);
                        else
                                usage();
                }
        }

        argc -= optind;
        argv += optind;
        if (argc < 0)
                usage();

        if (sign_progs && (private_key_path == NULL || cert_path == NULL)) {
                p_err("-i <identity_x509_cert> and -k <private_key> must be supplied with -S for signing");
                return -EINVAL;
        }

        if (!sign_progs && (private_key_path != NULL || cert_path != NULL)) {
                p_err("--sign (or -S) must be explicitly passed with -i <identity_x509_cert> and -k <private_key> to sign the programs");
                return -EINVAL;
        }

        if (version_requested)
                ret = do_version(argc, argv);
        else
                ret = cmd_select(commands, argc, argv, do_help);

        if (json_output)
                jsonw_destroy(&json_wtr);

        btf__free(base_btf);

        return ret;
}