/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * particular file as subject to the "Classpath" exception as provided

 *

 * This code 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 General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 */

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "jli_util.h"

#include <zlib.h>

#include "manifest_info.h"

static char     *manifest;

static const char       *manifest_name = "META-INF/MANIFEST.MF";

/*

 * Inflate the manifest file (or any file for that matter).

 *

 *   fd:        File descriptor of the jar file.

 *   entry:     Contains the information necessary to perform the inflation

 *              (the compressed and uncompressed sizes and the offset in

 *              the file where the compressed data is located).

 *   size_out:  Returns the size of the inflated file.

 *

 * Upon success, it returns a pointer to a NUL-terminated malloc'd buffer

 * containing the inflated manifest file.  When the caller is done with it,

 * this buffer should be released by a call to free().  Upon failure,

 * returns NULL.

 */

static char *

inflate_file(int fd, zentry *entry, int *size_out)

{

    char        *in;

    char        *out;

    z_stream    zs;

    if (entry->csize == (size_t) -1 || entry->isize == (size_t) -1 )

        return (NULL);

    if (lseek(fd, entry->offset, SEEK_SET) < (off_t)0)

        return (NULL);

    if ((in = malloc(entry->csize + 1)) == NULL)

        return (NULL);

    if ((size_t)(read(fd, in, (unsigned int)entry->csize)) != entry->csize) {

        free(in);

        return (NULL);

    }

    if (entry->how == STORED) {

        *(char *)((size_t)in + entry->csize) = '\0';

        if (size_out) {

            *size_out = entry->csize;

        }

        return (in);

    } else if (entry->how == DEFLATED) {

        zs.zalloc = (alloc_func)Z_NULL;

        zs.zfree = (free_func)Z_NULL;

        zs.opaque = (voidpf)Z_NULL;

        zs.next_in = (Byte*)in;

        zs.avail_in = (uInt)entry->csize;

        if (inflateInit2(&zs, -MAX_WBITS) < 0) {

            free(in);

            return (NULL);

        }

        if ((out = malloc(entry->isize + 1)) == NULL) {

            free(in);

            return (NULL);

        }

        zs.next_out = (Byte*)out;

        zs.avail_out = (uInt)entry->isize;

        if (inflate(&zs, Z_PARTIAL_FLUSH) < 0) {

            free(in);

            free(out);

            return (NULL);

        }

        *(char *)((size_t)out + entry->isize) = '\0';

        free(in);

        if (inflateEnd(&zs) < 0) {

            free(out);

            return (NULL);

        }

        if (size_out) {

            *size_out = entry->isize;

        }

        return (out);

    } else

        return (NULL);

}

/*

 * A very little used routine to handle the case that zip file has

 * a comment at the end. Believe it or not, the only way to find the

 * END record is to walk backwards, byte by bloody byte looking for

 * the END record signature.

 *

 *      fd:     File descriptor of the jar file.

 *      eb:     Pointer to a buffer to receive a copy of the END header.

 *

 * Returns the offset of the END record in the file on success,

 * -1 on failure.

 */

static off_t

find_end(int fd, Byte *eb)

{

    off_t   len;

    off_t   pos;

    off_t   flen;

    int     bytes;

    Byte    *cp;

    Byte    *endpos;

    Byte    *buffer;

    /*

     * 99.44% (or more) of the time, there will be no comment at the

     * end of the zip file.  Try reading just enough to read the END

     * record from the end of the file.

     */

    if ((pos = lseek(fd, -ENDHDR, SEEK_END)) < (off_t)0)

        return (-1);

    if ((bytes = read(fd, eb, ENDHDR)) < 0)

        return (-1);

    if (GETSIG(eb) == ENDSIG)

        return (pos);

    /*

     * Shucky-Darn,... There is a comment at the end of the zip file.

     *

     * Allocate and fill a buffer with enough of the zip file

     * to meet the specification for a maximal comment length.

     */

    if ((flen = lseek(fd, 0, SEEK_END)) < (off_t)0)

        return (-1);

    len = (flen < END_MAXLEN) ? flen : END_MAXLEN;

    if (lseek(fd, -len, SEEK_END) < (off_t)0)

        return (-1);

    if ((buffer = malloc(END_MAXLEN)) == NULL)

        return (-1);

    if ((bytes = read(fd, buffer, len)) < 0) {

        free(buffer);

        return (-1);

    }

    /*

     * Search backwards from the end of file stopping when the END header

     * signature is found. (The first condition of the "if" is just a

     * fast fail, because the GETSIG macro isn't always cheap.  The

     * final condition protects against false positives.)

     */

    endpos = &buffer[bytes];

    for (cp = &buffer[bytes - ENDHDR]; cp >= &buffer[0]; cp--)

        if ((*cp == (ENDSIG & 0xFF)) && (GETSIG(cp) == ENDSIG) &&

          (cp + ENDHDR + ENDCOM(cp) == endpos)) {

            (void) memcpy(eb, cp, ENDHDR);

            free(buffer);

            return (flen - (endpos - cp));

        }

    free(buffer);

    return (-1);

}

/*

 * Locate the manifest file with the zip/jar file.

 *

 *      fd:     File descriptor of the jar file.

 *      entry:  To be populated with the information necessary to perform

 *              the inflation (the compressed and uncompressed sizes and

 *              the offset in the file where the compressed data is located).

 *

 * Returns zero upon success. Returns a negative value upon failure.

 *

 * The buffer for reading the Central Directory if the zip/jar file needs

 * to be large enough to accommodate the largest possible single record

 * and the signature of the next record which is:

 *

 *      3*2**16 + CENHDR + SIGSIZ

 *

 * Each of the three variable sized fields (name, comment and extension)

 * has a maximum possible size of 64k.

 *

 * Typically, only a small bit of this buffer is used with bytes shuffled

 * down to the beginning of the buffer.  It is one thing to allocate such

 * a large buffer and another thing to actually start faulting it in.

 *

 * In most cases, all that needs to be read are the first two entries in

 * a typical jar file (META-INF and META-INF/MANIFEST.MF). Keep this factoid

 * in mind when optimizing this code.

 */

#define BUFSIZE (3 * 65536 + CENHDR + SIGSIZ)

#define MINREAD 1024

static int

find_file(int fd, zentry *entry, const char *file_name)

{

    int     bytes;

    int     res;

    int     entry_size;

    int     read_size;

    int     base_offset;

    Byte    *p;

    Byte    *bp;

    Byte    *buffer;

    Byte    locbuf[LOCHDR];

    if ((buffer = (Byte*)malloc(BUFSIZE)) == NULL) {

        return(-1);

    }

    p = buffer;

    bp = buffer;

    /*

     * Read the END Header, which is the starting point for ZIP files.

     * (Clearly designed to make writing a zip file easier than reading

     * one. Now isn't that precious...)

     */

    if ((base_offset = find_end(fd, bp)) == -1) {

        free(buffer);

        return (-1);

    }

    /*

     * There is a historical, but undocumented, ability to allow for

     * additional "stuff" to be prepended to the zip/jar file. It seems

     * that this has been used to prepend an actual java launcher

     * executable to the jar on Windows.  Although this is just another

     * form of statically linking a small piece of the JVM to the

     * application, we choose to continue to support it.  Note that no

     * guarantees have been made (or should be made) to the customer that

     * this will continue to work.

     *

     * Therefore, calculate the base offset of the zip file (within the

     * expanded file) by assuming that the central directory is followed

     * immediately by the end record.

     */

    base_offset = base_offset - ENDSIZ(p) - ENDOFF(p);

    /*

     * The END Header indicates the start of the Central Directory

     * Headers. Remember that the desired Central Directory Header (CEN)

     * will almost always be the second one and the first one is a small

     * directory entry ("META-INF/"). Keep the code optimized for

     * that case.

     *

     * Begin by seeking to the beginning of the Central Directory and

     * reading in the first buffer full of bits.

     */

    if (lseek(fd, base_offset + ENDOFF(p), SEEK_SET) < (off_t)0) {

        free(buffer);

        return (-1);

    }

    if ((bytes = read(fd, bp, MINREAD)) < 0) {

        free(buffer);

        return (-1);

    }

    /*

     * Loop through the Central Directory Headers. Note that a valid zip/jar

     * must have an ENDHDR (with ENDSIG) after the Central Directory.

     */

    while (GETSIG(p) == CENSIG) {

        /*

         * If a complete header isn't in the buffer, shift the contents

         * of the buffer down and refill the buffer.  Note that the check

         * for "bytes < CENHDR" must be made before the test for the entire

         * size of the header, because if bytes is less than CENHDR, the

         * actual size of the header can't be determined. The addition of

         * SIGSIZ guarantees that the next signature is also in the buffer

         * for proper loop termination.

         */

        if (bytes < CENHDR) {

            p = memmove(bp, p, bytes);

            if ((res = read(fd, bp + bytes, MINREAD)) <= 0) {

                free(buffer);

                return (-1);

            }

            bytes += res;

        }

        entry_size = CENHDR + CENNAM(p) + CENEXT(p) + CENCOM(p);

        if (bytes < entry_size + SIGSIZ) {

            if (p != bp)

                p = memmove(bp, p, bytes);

            read_size = entry_size - bytes + SIGSIZ;

            read_size = (read_size < MINREAD) ? MINREAD : read_size;

            if ((res = read(fd, bp + bytes,  read_size)) <= 0) {

                free(buffer);

                return (-1);

            }

            bytes += res;

        }

        /*

         * Check if the name is the droid we are looking for; the jar file

         * manifest.  If so, build the entry record from the data found in

         * the header located and return success.

         */

        if (CENNAM(p) == JLI_StrLen(file_name) &&

          memcmp((p + CENHDR), file_name, JLI_StrLen(file_name)) == 0) {

            if (lseek(fd, base_offset + CENOFF(p), SEEK_SET) < (off_t)0) {

                free(buffer);

                return (-1);

            }

            if (read(fd, locbuf, LOCHDR) < 0) {

                free(buffer);

                return (-1);

            }

            if (GETSIG(locbuf) != LOCSIG) {

                free(buffer);

                return (-1);

            }

            entry->isize = CENLEN(p);

            entry->csize = CENSIZ(p);

            entry->offset = base_offset + CENOFF(p) + LOCHDR +

                LOCNAM(locbuf) + LOCEXT(locbuf);

            entry->how = CENHOW(p);

            free(buffer);

            return (0);

        }

        /*

         * Point to the next entry and decrement the count of valid remaining

         * bytes.

         */

        bytes -= entry_size;

        p += entry_size;

    }

    free(buffer);

    return (-1);        /* Fell off the end the loop without a Manifest */

}

/*

 * Parse a Manifest file header entry into a distinct "name" and "value".

 * Continuation lines are joined into a single "value". The documented

 * syntax for a header entry is:

 *

 *      header: name ":" value

 *

 *      name: alphanum *headerchar

 *

 *      value: SPACE *otherchar newline *continuation

 *

 *      continuation: SPACE *otherchar newline

 *

 *      newline: CR LF | LF | CR (not followed by LF)

 *

 *      alphanum: {"A"-"Z"} | {"a"-"z"} | {"0"-"9"}

 *

 *      headerchar: alphanum | "-" | "_"

 *

 *      otherchar: any UTF-8 character except NUL, CR and LF

 *

 * Note that a manifest file may be composed of multiple sections,

 * each of which may contain multiple headers.

 *

 *      section: *header +newline

 *

 *      nonempty-section: +header +newline

 *

 * (Note that the point of "nonempty-section" is unclear, because it isn't

 * referenced elsewhere in the full specification for the Manifest file.)

 *

 * Arguments:

 *      lp      pointer to a character pointer which points to the start

 *              of a valid header.

 *      name    pointer to a character pointer which will be set to point

 *              to the name portion of the header (nul terminated).

 *      value   pointer to a character pointer which will be set to point

 *              to the value portion of the header (nul terminated).

 *

 * Returns:

 *    1 Successful parsing of an NV pair.  lp is updated to point to the

 *      next character after the terminating newline in the string

 *      representing the Manifest file. name and value are updated to

 *      point to the strings parsed.

 *    0 A valid end of section indicator was encountered.  lp, name, and

 *      value are not modified.

 *   -1 lp does not point to a valid header. Upon return, the values of

 *      lp, name, and value are undefined.

 */

static int

parse_nv_pair(char **lp, char **name, char **value)

{

    char    *nl;

    char    *cp;

    /*

     * End of the section - return 0. The end of section condition is

     * indicated by either encountering a blank line or the end of the

     * Manifest "string" (EOF).

     */

    if (**lp == '\0' || **lp == '\n' || **lp == '\r')

        return (0);

    /*

     * Getting to here, indicates that *lp points to an "otherchar".

     * Turn the "header" into a string on its own.

     */

    nl = JLI_StrPBrk(*lp, "\n\r");

    if (nl == NULL) {

        nl = JLI_StrChr(*lp, (int)'\0');

    } else {

        cp = nl;                        /* For merging continuation lines */

        if (*nl == '\r' && *(nl+1) == '\n')

            *nl++ = '\0';

        *nl++ = '\0';

        /*

         * Process any "continuation" line(s), by making them part of the

         * "header" line. Yes, I know that we are "undoing" the NULs we

         * just placed here, but continuation lines are the fairly rare

         * case, so we shouldn't unnecessarily complicate the code above.

         *

         * Note that an entire continuation line is processed each iteration

         * through the outer while loop.

         */

        while (*nl == ' ') {

            nl++;                       /* First character to be moved */

            while (*nl != '\n' && *nl != '\r' && *nl != '\0')

                *cp++ = *nl++;          /* Shift string */

            if (*nl == '\0')

                return (-1);            /* Error: newline required */

            *cp = '\0';

            if (*nl == '\r' && *(nl+1) == '\n')

                *nl++ = '\0';

            *nl++ = '\0';

        }

    }

    /*

     * Separate the name from the value;

     */

    cp = JLI_StrChr(*lp, (int)':');

    if (cp == NULL)

        return (-1);

    *cp++ = '\0';               /* The colon terminates the name */

    if (*cp != ' ')

        return (-1);

    *cp++ = '\0';               /* Eat the required space */

    *name = *lp;

    *value = cp;

    *lp = nl;

    return (1);

}

/*

 * Read the manifest from the specified jar file and fill in the manifest_info

 * structure with the information found within.

 *

 * Error returns are as follows:

 *    0 Success

 *   -1 Unable to open jarfile

 *   -2 Error accessing the manifest from within the jarfile (most likely

 *      a manifest is not present, or this isn't a valid zip/jar file).

 */

int

JLI_ParseManifest(char *jarfile, manifest_info *info)

{

    int     fd;

    zentry  entry;

    char    *lp;

    char    *name;

    char    *value;

    int     rc;

    char    *splashscreen_name = NULL;

    if ((fd = open(jarfile, O_RDONLY

#ifdef O_BINARY

        | O_BINARY /* use binary mode on windows */

#endif

        )) == -1)

        return (-1);

    info->manifest_version = NULL;

    info->main_class = NULL;

    info->jre_version = NULL;

    info->jre_restrict_search = 0;

    info->splashscreen_image_file_name = NULL;

    if (rc = find_file(fd, &entry, manifest_name) != 0) {

        close(fd);

        return (-2);

    }

    manifest = inflate_file(fd, &entry, NULL);

    if (manifest == NULL) {

        close(fd);

        return (-2);

    }

    lp = manifest;

    while ((rc = parse_nv_pair(&lp, &name, &value)) > 0) {

        if (JLI_StrCaseCmp(name, "Manifest-Version") == 0)

            info->manifest_version = value;

        else if (JLI_StrCaseCmp(name, "Main-Class") == 0)

            info->main_class = value;

        else if (JLI_StrCaseCmp(name, "JRE-Version") == 0)

            info->jre_version = value;

        else if (JLI_StrCaseCmp(name, "JRE-Restrict-Search") == 0) {

            if (JLI_StrCaseCmp(value, "true") == 0)

                info->jre_restrict_search = 1;

        } else if (JLI_StrCaseCmp(name, "Splashscreen-Image") == 0) {

            info->splashscreen_image_file_name = value;

        }

    }

    close(fd);

    if (rc == 0)

        return (0);