/*

 * Unix support routines for PhysicsFS.

 *

 * Please see the file LICENSE.txt in the source's root directory.

 *

 *  This file written by Ryan C. Gordon.

 */

#define __PHYSICSFS_INTERNAL__

#include "physfs_platforms.h"

#ifdef PHYSFS_PLATFORM_UNIX

#include <ctype.h>

#include <unistd.h>

#include <stdlib.h>

#include <sys/types.h>

#include <pwd.h>

#include <sys/stat.h>

#include <sys/param.h>

#include <dirent.h>

#include <time.h>

#include <errno.h>

#include <limits.h>

#if PHYSFS_PLATFORM_LINUX && !defined(PHYSFS_HAVE_MNTENT_H)

#define PHYSFS_HAVE_MNTENT_H 1

#elif PHYSFS_PLATFORM_SOLARIS && !defined(PHYSFS_HAVE_SYS_MNTTAB_H)

#define PHYSFS_HAVE_SYS_MNTTAB_H 1

#elif PHYSFS_PLATFORM_BSD && !defined(PHYSFS_HAVE_SYS_UCRED_H)

#define PHYSFS_HAVE_SYS_UCRED_H 1

#endif

#ifdef PHYSFS_HAVE_SYS_UCRED_H

#  ifdef PHYSFS_HAVE_MNTENT_H

#    undef PHYSFS_HAVE_MNTENT_H /* don't do both... */

#  endif

#  include <sys/mount.h>

#  include <sys/ucred.h>

#endif

#ifdef PHYSFS_HAVE_MNTENT_H

#include <mntent.h>

#endif

#ifdef PHYSFS_HAVE_SYS_MNTTAB_H

#include <sys/mnttab.h>

#endif

#include "physfs_internal.h"

int __PHYSFS_platformInit(void)

{

    return 1;  /* always succeed. */

} /* __PHYSFS_platformInit */

int __PHYSFS_platformDeinit(void)

{

    return 1;  /* always succeed. */

} /* __PHYSFS_platformDeinit */

/* Stub version for platforms without CD-ROM support. */

void __PHYSFS_platformDetectAvailableCDs(PHYSFS_StringCallback cb, void *data)

{

#if (defined PHYSFS_NO_CDROM_SUPPORT)

    /* no-op. */

#elif (defined PHYSFS_HAVE_SYS_UCRED_H)

    int i;

    struct statfs *mntbufp = NULL;

    int mounts = getmntinfo(&mntbufp, MNT_WAIT);

    for (i = 0; i < mounts; i++)

    {

        int add_it = 0;

        if (strcmp(mntbufp[i].f_fstypename, "iso9660") == 0)

            add_it = 1;

        else if (strcmp( mntbufp[i].f_fstypename, "cd9660") == 0)

            add_it = 1;

        /* add other mount types here */

        if (add_it)

            cb(data, mntbufp[i].f_mntonname);

    } /* for */

#elif (defined PHYSFS_HAVE_MNTENT_H)

    FILE *mounts = NULL;

    struct mntent *ent = NULL;

    mounts = setmntent("/etc/mtab", "r");

    BAIL_IF_MACRO(mounts == NULL, PHYSFS_ERR_IO, /*return void*/);

    while ( (ent = getmntent(mounts)) != NULL )

    {

        int add_it = 0;

        if (strcmp(ent->mnt_type, "iso9660") == 0)

            add_it = 1;

        else if (strcmp(ent->mnt_type, "udf") == 0)

            add_it = 1;

        /* !!! FIXME: these might pick up floppy drives, right? */

        else if (strcmp(ent->mnt_type, "auto") == 0)

            add_it = 1;

        else if (strcmp(ent->mnt_type, "supermount") == 0)

            add_it = 1;

        /* !!! FIXME: udf? automount? */

        /* add other mount types here */

        if (add_it)

            cb(data, ent->mnt_dir);

    } /* while */

    endmntent(mounts);

#elif (defined PHYSFS_HAVE_SYS_MNTTAB_H)

    FILE *mounts = fopen(MNTTAB, "r");

    struct mnttab ent;

    BAIL_IF_MACRO(mounts == NULL, PHYSFS_ERR_IO, /*return void*/);

    while (getmntent(mounts, &ent) == 0)

    {

        int add_it = 0;

        if (strcmp(ent.mnt_fstype, "hsfs") == 0)

            add_it = 1;

        /* add other mount types here */

        if (add_it)

            cb(data, ent.mnt_mountp);

    } /* while */

    fclose(mounts);

#else

#error Unknown platform. Should have defined PHYSFS_NO_CDROM_SUPPORT, perhaps.

#endif

} /* __PHYSFS_platformDetectAvailableCDs */

/*

 * See where program (bin) resides in the $PATH specified by (envr).

 *  returns a copy of the first element in envr that contains it, or NULL

 *  if it doesn't exist or there were other problems. PHYSFS_SetError() is

 *  called if we have a problem.

 *

 * (envr) will be scribbled over, and you are expected to allocator.Free() the

 *  return value when you're done with it.

 */

static char *findBinaryInPath(const char *bin, char *envr)

{

    size_t alloc_size = 0;

    char *exe = NULL;

    char *start = envr;

    char *ptr;

    assert(bin != NULL);

    assert(envr != NULL);

    do

    {

        size_t size;

        size_t binlen;

        ptr = strchr(start, ':');  /* find next $PATH separator. */

        if (ptr)

            *ptr = '\0';

        binlen = strlen(bin);

        size = strlen(start) + binlen + 2;

        if (size >= alloc_size)

        {

            char *x = (char *) allocator.Realloc(exe, size);

            if (!x)

            {

                if (exe != NULL)

                    allocator.Free(exe);

                BAIL_MACRO(PHYSFS_ERR_OUT_OF_MEMORY, NULL);

            } /* if */

            alloc_size = size;

            exe = x;

        } /* if */

        /* build full binary path... */

        strcpy(exe, start);

        if ((exe[0] == '\0') || (exe[strlen(exe) - 1] != '/'))

            strcat(exe, "/");

        strcat(exe, bin);

        if (access(exe, X_OK) == 0)  /* Exists as executable? We're done. */

        {

            exe[(size - binlen) - 1] = '\0'; /* chop off filename, leave '/' */

            return exe;

        } /* if */

        start = ptr + 1;  /* start points to beginning of next element. */

    } while (ptr != NULL);

    if (exe != NULL)

        allocator.Free(exe);

    return NULL;  /* doesn't exist in path. */

} /* findBinaryInPath */

static char *readSymLink(const char *path)

{

    ssize_t len = 64;

    ssize_t rc = -1;

    char *retval = NULL;

    while (1)

    {

         char *ptr = (char *) allocator.Realloc(retval, (size_t) len);

         if (ptr == NULL)

             break;   /* out of memory. */

         retval = ptr;

         rc = readlink(path, retval, len);

         if (rc == -1)

             break;  /* not a symlink, i/o error, etc. */

         else if (rc < len)

         {

             retval[rc] = '\0';  /* readlink doesn't null-terminate. */

             return retval;  /* we're good to go. */

         } /* else if */

         len *= 2;  /* grow buffer, try again. */

    } /* while */

    if (retval != NULL)

        allocator.Free(retval);

    return NULL;

} /* readSymLink */

char *__PHYSFS_platformCalcBaseDir(const char *argv0)

{

    char *retval = NULL;

    const char *envr = NULL;

    /* Try to avoid using argv0 unless forced to. Try system-specific stuff. */

    #if PHYSFS_PLATFORM_FREEBSD

    {

        char fullpath[PATH_MAX];

        size_t buflen = sizeof (fullpath);

        int mib[4] = { CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1 };

        if (sysctl(mib, 4, fullpath, &buflen, NULL, 0) != -1)

            retval = __PHYSFS_strdup(fullpath);

    }

    #elif PHYSFS_PLATFORM_SOLARIS

    {

        const char *path = getexecname();

        if ((path != NULL) && (path[0] == '/'))  /* must be absolute path... */

            retval = __PHYSFS_strdup(path);

    }

    #endif

    if (retval)

        return retval;   /* already got it. */

    /* If there's a Linux-like /proc filesystem, you can get the full path to

     *  the current process from a symlink in there.

     */

    if (access("/proc", F_OK) == 0)

    {

        retval = readSymLink("/proc/self/exe");

        if (!retval) retval = readSymLink("/proc/curproc/file");

        if (!retval) retval = readSymLink("/proc/curproc/exe");

        if (retval == NULL)

        {

            /* older kernels don't have /proc/self ... try PID version... */

            const unsigned long long pid = (unsigned long long) getpid();

            char path[64];

            const int rc = (int) snprintf(path,sizeof(path),"/proc/%llu/exe",pid);

            if ( (rc > 0) && (rc < sizeof(path)) )

                retval = readSymLink(path);

        } /* if */

    } /* if */

    if (retval != NULL)  /* chop off filename. */

    {

        char *ptr = strrchr(retval, '/');

        if (ptr != NULL)

            *(ptr+1) = '\0';

        else  /* shouldn't happen, but just in case... */

        {

            allocator.Free(retval);

            retval = NULL;

        } /* else */

    } /* if */

    /* No /proc/self/exe, etc, but we have an argv[0] we can parse? */

    if ((retval == NULL) && (argv0 != NULL))

    {

        /* fast path: default behaviour can handle this. */

        if (strchr(argv0, '/') != NULL)

            return NULL;  /* higher level parses out real path from argv0. */

        /* If there's no dirsep on argv0, then look through $PATH for it. */

        envr = getenv("PATH");

        if (envr != NULL)

        {

            char *path = (char *) __PHYSFS_smallAlloc(strlen(envr) + 1);

            BAIL_IF_MACRO(!path, PHYSFS_ERR_OUT_OF_MEMORY, NULL);

            strcpy(path, envr);

            retval = findBinaryInPath(argv0, path);

            __PHYSFS_smallFree(path);

        } /* if */

    } /* if */

    if (retval != NULL)

    {

        /* try to shrink buffer... */

        char *ptr = (char *) allocator.Realloc(retval, strlen(retval) + 1);

        if (ptr != NULL)

            retval = ptr;  /* oh well if it failed. */

    } /* if */

    return retval;

} /* __PHYSFS_platformCalcBaseDir */

char *__PHYSFS_platformCalcPrefDir(const char *org, const char *app)

{

    /*

     * We use XDG's base directory spec, even if you're not on Linux.

     *  This isn't strictly correct, but the results are relatively sane

     *  in any case.

     *

     * https://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html

     */

    const char *envr = getenv("XDG_DATA_HOME");

    const char *append = "/";

    char *retval = NULL;

    size_t len = 0;

    if (!envr)

    {

        /* You end up with "$HOME/.local/share/Game Name 2" */

        envr = __PHYSFS_getUserDir();

        BAIL_IF_MACRO(!envr, ERRPASS, NULL);  /* oh well. */

        append = ".local/share/";

    } /* if */

    len = strlen(envr) + strlen(append) + strlen(app) + 2;

    retval = (char *) allocator.Malloc(len);

    BAIL_IF_MACRO(!retval, PHYSFS_ERR_OUT_OF_MEMORY, NULL);

    snprintf(retval, len, "%s%s%s/", envr, append, app);

    return retval;

} /* __PHYSFS_platformCalcPrefDir */

int __PHYSFS_platformSetDefaultAllocator(PHYSFS_Allocator *a)

{

    return 0;  /* just use malloc() and friends. */

} /* __PHYSFS_platformSetDefaultAllocator */

#endif /* PHYSFS_PLATFORM_UNIX */

/* end of unix.c ... */