/*
 * Copyright (c) 2011 The Chromium OS Authors.
 * SPDX-License-Identifier:     GPL-2.0+
 */

#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <time.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <linux/types.h>

#include <asm/getopt.h>
#include <asm/sections.h>
#include <asm/state.h>
#include <os.h>
#include <rtc_def.h>

/* Operating System Interface */

struct os_mem_hdr {
        size_t length;          /* number of bytes in the block */
};

ssize_t os_read(int fd, void *buf, size_t count)
{
        return read(fd, buf, count);
}

ssize_t os_read_no_block(int fd, void *buf, size_t count)
{
        const int flags = fcntl(fd, F_GETFL, 0);

        fcntl(fd, F_SETFL, flags | O_NONBLOCK);
        return os_read(fd, buf, count);
}

ssize_t os_write(int fd, const void *buf, size_t count)
{
        return write(fd, buf, count);
}

off_t os_lseek(int fd, off_t offset, int whence)
{
        if (whence == OS_SEEK_SET)
                whence = SEEK_SET;
        else if (whence == OS_SEEK_CUR)
                whence = SEEK_CUR;
        else if (whence == OS_SEEK_END)
                whence = SEEK_END;
        else
                os_exit(1);
        return lseek(fd, offset, whence);
}

int os_open(const char *pathname, int os_flags)
{
        int flags;

        switch (os_flags & OS_O_MASK) {
        case OS_O_RDONLY:
        default:
                flags = O_RDONLY;
                break;

        case OS_O_WRONLY:
                flags = O_WRONLY;
                break;

        case OS_O_RDWR:
                flags = O_RDWR;
                break;
        }

        if (os_flags & OS_O_CREAT)
                flags |= O_CREAT;

        return open(pathname, flags, 0777);
}

int os_close(int fd)
{
        return close(fd);
}

int os_unlink(const char *pathname)
{
        return unlink(pathname);
}

void os_exit(int exit_code)
{
        exit(exit_code);
}

/* Restore tty state when we exit */
static struct termios orig_term;
static bool term_setup;

void os_fd_restore(void)
{
        if (term_setup) {
                tcsetattr(0, TCSANOW, &orig_term);
                term_setup = false;
        }
}

/* Put tty into raw mode so <tab> and <ctrl+c> work */
void os_tty_raw(int fd, bool allow_sigs)
{
        struct termios term;

        if (term_setup)
                return;

        /* If not a tty, don't complain */
        if (tcgetattr(fd, &orig_term))
                return;

        term = orig_term;
        term.c_iflag = IGNBRK | IGNPAR;
        term.c_oflag = OPOST | ONLCR;
        term.c_cflag = CS8 | CREAD | CLOCAL;
        term.c_lflag = allow_sigs ? ISIG : 0;
        if (tcsetattr(fd, TCSANOW, &term))
                return;

        term_setup = true;
        atexit(os_fd_restore);
}

void *os_malloc(size_t length)
{
        struct os_mem_hdr *hdr;

        hdr = mmap(NULL, length + sizeof(*hdr), PROT_READ | PROT_WRITE,
                   MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
        if (hdr == MAP_FAILED)
                return NULL;
        hdr->length = length;

        return hdr + 1;
}

void os_free(void *ptr)
{
        struct os_mem_hdr *hdr = ptr;

        hdr--;
        if (ptr)
                munmap(hdr, hdr->length + sizeof(*hdr));
}

void *os_realloc(void *ptr, size_t length)
{
        struct os_mem_hdr *hdr = ptr;
        void *buf = NULL;

        hdr--;
        if (length != 0) {
                buf = os_malloc(length);
                if (!buf)
                        return buf;
                if (ptr) {
                        if (length > hdr->length)
                                length = hdr->length;
                        memcpy(buf, ptr, length);
                }
        }
        os_free(ptr);

        return buf;
}

void os_usleep(unsigned long usec)
{
        usleep(usec);
}

uint64_t __attribute__((no_instrument_function)) os_get_nsec(void)
{
#if defined(CLOCK_MONOTONIC) && defined(_POSIX_MONOTONIC_CLOCK)
        struct timespec tp;
        if (EINVAL == clock_gettime(CLOCK_MONOTONIC, &tp)) {
                struct timeval tv;

                gettimeofday(&tv, NULL);
                tp.tv_sec = tv.tv_sec;
                tp.tv_nsec = tv.tv_usec * 1000;
        }
        return tp.tv_sec * 1000000000ULL + tp.tv_nsec;
#else
        struct timeval tv;
        gettimeofday(&tv, NULL);
        return tv.tv_sec * 1000000000ULL + tv.tv_usec * 1000;
#endif
}

static char *short_opts;
static struct option *long_opts;

int os_parse_args(struct sandbox_state *state, int argc, char *argv[])
{
        struct sandbox_cmdline_option **sb_opt = __u_boot_sandbox_option_start;
        size_t num_options = __u_boot_sandbox_option_count();
        size_t i;

        int hidden_short_opt;
        size_t si;

        int c;

        if (short_opts || long_opts)
                return 1;

        state->argc = argc;
        state->argv = argv;

        /* dynamically construct the arguments to the system getopt_long */
        short_opts = os_malloc(sizeof(*short_opts) * num_options * 2 + 1);
        long_opts = os_malloc(sizeof(*long_opts) * num_options);
        if (!short_opts || !long_opts)
                return 1;

        /*
         * getopt_long requires "val" to be unique (since that is what the
         * func returns), so generate unique values automatically for flags
         * that don't have a short option.  pick 0x100 as that is above the
         * single byte range (where ASCII/ISO-XXXX-X charsets live).
         */
        hidden_short_opt = 0x100;
        si = 0;
        for (i = 0; i < num_options; ++i) {
                long_opts[i].name = sb_opt[i]->flag;
                long_opts[i].has_arg = sb_opt[i]->has_arg ?
                        required_argument : no_argument;
                long_opts[i].flag = NULL;

                if (sb_opt[i]->flag_short) {
                        short_opts[si++] = long_opts[i].val = sb_opt[i]->flag_short;
                        if (long_opts[i].has_arg == required_argument)
                                short_opts[si++] = ':';
                } else
                        long_opts[i].val = sb_opt[i]->flag_short = hidden_short_opt++;
        }
        short_opts[si] = '\0';

        /* we need to handle output ourselves since u-boot provides printf */
        opterr = 0;

        /*
         * walk all of the options the user gave us on the command line,
         * figure out what u-boot option structure they belong to (via
         * the unique short val key), and call the appropriate callback.
         */
        while ((c = getopt_long(argc, argv, short_opts, long_opts, NULL)) != -1) {
                for (i = 0; i < num_options; ++i) {
                        if (sb_opt[i]->flag_short == c) {
                                if (sb_opt[i]->callback(state, optarg)) {
                                        state->parse_err = sb_opt[i]->flag;
                                        return 0;
                                }
                                break;
                        }
                }
                if (i == num_options) {
                        /*
                         * store the faulting flag for later display.  we have to
                         * store the flag itself as the getopt parsing itself is
                         * tricky: need to handle the following flags (assume all
                         * of the below are unknown):
                         *   -a        optopt='a' optind=<next>
                         *   -abbbb    optopt='a' optind=<this>
                         *   -aaaaa    optopt='a' optind=<this>
                         *   --a       optopt=0   optind=<this>
                         * as you can see, it is impossible to determine the exact
                         * faulting flag without doing the parsing ourselves, so
                         * we just report the specific flag that failed.
                         */
                        if (optopt) {
                                static char parse_err[3] = { '-', 0, '\0', };
                                parse_err[1] = optopt;
                                state->parse_err = parse_err;
                        } else
                                state->parse_err = argv[optind - 1];
                        break;
                }
        }

        return 0;
}

void os_dirent_free(struct os_dirent_node *node)
{
        struct os_dirent_node *next;

        while (node) {
                next = node->next;
                free(node);
                node = next;
        }
}

int os_dirent_ls(const char *dirname, struct os_dirent_node **headp)
{
        struct dirent entry, *result;
        struct os_dirent_node *head, *node, *next;
        struct stat buf;
        DIR *dir;
        int ret;
        char *fname;
        int len;

        *headp = NULL;
        dir = opendir(dirname);
        if (!dir)
                return -1;

        /* Create a buffer for the maximum filename length */
        len = sizeof(entry.d_name) + strlen(dirname) + 2;
        fname = malloc(len);
        if (!fname) {
                ret = -ENOMEM;
                goto done;
        }

        for (node = head = NULL;; node = next) {
                ret = readdir_r(dir, &entry, &result);
                if (ret || !result)
                        break;
                next = malloc(sizeof(*node) + strlen(entry.d_name) + 1);
                if (!next) {
                        os_dirent_free(head);
                        ret = -ENOMEM;
                        goto done;
                }
                next->next = NULL;
                strcpy(next->name, entry.d_name);
                switch (entry.d_type) {
                case DT_REG:
                        next->type = OS_FILET_REG;
                        break;
                case DT_DIR:
                        next->type = OS_FILET_DIR;
                        break;
                case DT_LNK:
                        next->type = OS_FILET_LNK;
                        break;
                }
                next->size = 0;
                snprintf(fname, len, "%s/%s", dirname, next->name);
                if (!stat(fname, &buf))
                        next->size = buf.st_size;
                if (node)
                        node->next = next;
                if (!head)
                        head = node;
        }
        *headp = head;

done:
        closedir(dir);
        free(fname);
        return ret;
}

const char *os_dirent_typename[OS_FILET_COUNT] = {
        "   ",
        "SYM",
        "DIR",
        "???",
};

const char *os_dirent_get_typename(enum os_dirent_t type)
{
        if (type >= 0 && type < OS_FILET_COUNT)
                return os_dirent_typename[type];

        return os_dirent_typename[OS_FILET_UNKNOWN];
}

int os_get_filesize(const char *fname, loff_t *size)
{
        struct stat buf;
        int ret;

        ret = stat(fname, &buf);
        if (ret)
                return ret;
        *size = buf.st_size;
        return 0;
}

void os_putc(int ch)
{
        putchar(ch);
}

void os_puts(const char *str)
{
        while (*str)
                os_putc(*str++);
}

int os_write_ram_buf(const char *fname)
{
        struct sandbox_state *state = state_get_current();
        int fd, ret;

        fd = open(fname, O_CREAT | O_WRONLY, 0777);
        if (fd < 0)
                return -ENOENT;
        ret = write(fd, state->ram_buf, state->ram_size);
        close(fd);
        if (ret != state->ram_size)
                return -EIO;

        return 0;
}

int os_read_ram_buf(const char *fname)
{
        struct sandbox_state *state = state_get_current();
        int fd, ret;
        loff_t size;

        ret = os_get_filesize(fname, &size);
        if (ret < 0)
                return ret;
        if (size != state->ram_size)
                return -ENOSPC;
        fd = open(fname, O_RDONLY);
        if (fd < 0)
                return -ENOENT;

        ret = read(fd, state->ram_buf, state->ram_size);
        close(fd);
        if (ret != state->ram_size)
                return -EIO;

        return 0;
}

static int make_exec(char *fname, const void *data, int size)
{
        int fd;

        strcpy(fname, "/tmp/u-boot.jump.XXXXXX");
        fd = mkstemp(fname);
        if (fd < 0)
                return -ENOENT;
        if (write(fd, data, size) < 0)
                return -EIO;
        close(fd);
        if (chmod(fname, 0777))
                return -ENOEXEC;

        return 0;
}

static int add_args(char ***argvp, const char *add_args[], int count)
{
        char **argv;
        int argc;

        for (argv = *argvp, argc = 0; (*argvp)[argc]; argc++)
                ;

        argv = malloc((argc + count + 1) * sizeof(char *));
        if (!argv) {
                printf("Out of memory for %d argv\n", count);
                return -ENOMEM;
        }
        memcpy(argv, *argvp, argc * sizeof(char *));
        memcpy(argv + argc, add_args, count * sizeof(char *));
        argv[argc + count] = NULL;

        *argvp = argv;
        return 0;
}

int os_jump_to_image(const void *dest, int size)
{
        struct sandbox_state *state = state_get_current();
        char fname[30], mem_fname[30];
        int fd, err;
        const char *extra_args[5];
        char **argv = state->argv;
#ifdef DEBUG
        int argc, i;
#endif

        err = make_exec(fname, dest, size);
        if (err)
                return err;

        strcpy(mem_fname, "/tmp/u-boot.mem.XXXXXX");
        fd = mkstemp(mem_fname);
        if (fd < 0)
                return -ENOENT;
        close(fd);
        err = os_write_ram_buf(mem_fname);
        if (err)
                return err;

        os_fd_restore();

        extra_args[0] = "-j";
        extra_args[1] = fname;
        extra_args[2] = "-m";
        extra_args[3] = mem_fname;
        extra_args[4] = "--rm_memory";
        err = add_args(&argv, extra_args,
                       sizeof(extra_args) / sizeof(extra_args[0]));
        if (err)
                return err;

#ifdef DEBUG
        for (i = 0; argv[i]; i++)
                printf("%d %s\n", i, argv[i]);
#endif

        if (state_uninit())
                os_exit(2);

        err = execv(fname, argv);
        free(argv);
        if (err)
                return err;

        return unlink(fname);
}

void os_localtime(struct rtc_time *rt)
{
        time_t t = time(NULL);
        struct tm *tm;

        tm = localtime(&t);
        rt->tm_sec = tm->tm_sec;
        rt->tm_min = tm->tm_min;
        rt->tm_hour = tm->tm_hour;
        rt->tm_mday = tm->tm_mday;
        rt->tm_mon = tm->tm_mon + 1;
        rt->tm_year = tm->tm_year + 1900;
        rt->tm_wday = tm->tm_wday;
        rt->tm_yday = tm->tm_yday;
        rt->tm_isdst = tm->tm_isdst;
}