process.c

压缩解压,是unzip540的升级,这个外国网站摘来的源码,是evb编写.

    TTrace((stderr,"\nef_scan_for_izux: scanning extra field of length %u\n",
      ef_len));

    while (ef_len >= EB_HEADSIZE) {
        eb_id = makeword(EB_ID + ef_buf);
        eb_len = makeword(EB_LEN + ef_buf);

        if (eb_len > (ef_len - EB_HEADSIZE)) {
            /* discovered some extra field inconsistency! */
            TTrace((stderr,
              "ef_scan_for_izux: block length %u > rest ef_size %u\n", eb_len,
              ef_len - EB_HEADSIZE));
            break;
        }

        switch (eb_id) {
          case EF_TIME:
            flags &= ~0x0ff;    /* ignore previous IZUNIX or EF_TIME fields */
            have_new_type_eb = TRUE;
            if ( eb_len >= EB_UT_MINLEN && z_utim != NULL) {
                unsigned eb_idx = EB_UT_TIME1;
                TTrace((stderr,"ef_scan_for_izux: found TIME extra field\n"));
                flags |= (ef_buf[EB_HEADSIZE+EB_UT_FLAGS] & 0x0ff);
                if ((flags & EB_UT_FL_MTIME)) {
                    if ((eb_idx+4) <= eb_len) {
                        i_time = (long)makelong((EB_HEADSIZE+eb_idx) + ef_buf);
                        eb_idx += 4;
                        TTrace((stderr,"  UT e.f. modification time = %ld\n",
                                i_time));

#ifdef TIME_T_TYPE_DOUBLE
                        if ((ulg)(i_time) & (ulg)(0x80000000L)) {
                            if (dos_mdatetime == DOSTIME_MINIMUM) {
                              ut_in_archive_sgn = -1;
                              z_utim->mtime =
                                (time_t)((long)i_time | (~(long)0x7fffffffL));
                            } else if (dos_mdatetime >= DOSTIME_2038_01_18) {
                              ut_in_archive_sgn = 1;
                              z_utim->mtime =
                                (time_t)((ulg)i_time & (ulg)0xffffffffL);
                            } else {
                              ut_in_archive_sgn = 0;
                              /* cannot determine sign of mtime;
                                 without modtime: ignore complete UT field */
                              flags &= ~0x0ff;  /* no time_t times available */
                              TTrace((stderr,
                                "  UT modtime range error; ignore e.f.!\n"));
                              break;            /* stop scanning this field */
                            }
                        } else {
                            /* cannot determine, safe assumption is FALSE */
                            ut_in_archive_sgn = 0;
                            z_utim->mtime = (time_t)i_time;
                        }
#else /* !TIME_T_TYPE_DOUBLE */
                        if ((ulg)(i_time) & (ulg)(0x80000000L)) {
                            ut_zip_unzip_compatible =
                              ((time_t)0x80000000L < (time_t)0L)
                              ? (dos_mdatetime == DOSTIME_MINIMUM)
                              : (dos_mdatetime >= DOSTIME_2038_01_18);
                            if (!ut_zip_unzip_compatible) {
                              /* UnZip interprets mtime differently than Zip;
                                 without modtime: ignore complete UT field */
                              flags &= ~0x0ff;  /* no time_t times available */
                              TTrace((stderr,
                                "  UT modtime range error; ignore e.f.!\n"));
                              break;            /* stop scanning this field */
                            }
                        } else {
                            /* cannot determine, safe assumption is FALSE */
                            ut_zip_unzip_compatible = FALSE;
                        }
                        z_utim->mtime = (time_t)i_time;
#endif /* ?TIME_T_TYPE_DOUBLE */
                    } else {
                        flags &= ~EB_UT_FL_MTIME;
                        TTrace((stderr,"  UT e.f. truncated; no modtime\n"));
                    }
                }
                if (ef_is_c) {
                    break;      /* central version of TIME field ends here */
                }

                if (flags & EB_UT_FL_ATIME) {
                    if ((eb_idx+4) <= eb_len) {
                        i_time = (long)makelong((EB_HEADSIZE+eb_idx) + ef_buf);
                        eb_idx += 4;
                        TTrace((stderr,"  UT e.f. access time = %ld\n",
                                i_time));
#ifdef TIME_T_TYPE_DOUBLE
                        if ((ulg)(i_time) & (ulg)(0x80000000L)) {
                            if (ut_in_archive_sgn == -1)
                              z_utim->atime =
                                (time_t)((long)i_time | (~(long)0x7fffffffL));
                            } else if (ut_in_archive_sgn == 1) {
                              z_utim->atime =
                                (time_t)((ulg)i_time & (ulg)0xffffffffL);
                            } else {
                              /* sign of 32-bit time is unknown -> ignore it */
                              flags &= ~EB_UT_FL_ATIME;
                              TTrace((stderr,
                                "  UT access time range error: skip time!\n"));
                            }
                        } else {
                            z_utim->atime = (time_t)i_time;
                        }
#else /* !TIME_T_TYPE_DOUBLE */
                        if (((ulg)(i_time) & (ulg)(0x80000000L)) &&
                            !ut_zip_unzip_compatible) {
                            flags &= ~EB_UT_FL_ATIME;
                            TTrace((stderr,
                              "  UT access time range error: skip time!\n"));
                        } else {
                            z_utim->atime = (time_t)i_time;
                        }
#endif /* ?TIME_T_TYPE_DOUBLE */
                    } else {
                        flags &= ~EB_UT_FL_ATIME;
                    }
                }
                if (flags & EB_UT_FL_CTIME) {
                    if ((eb_idx+4) <= eb_len) {
                        i_time = (long)makelong((EB_HEADSIZE+eb_idx) + ef_buf);
                        TTrace((stderr,"  UT e.f. creation time = %ld\n",
                                i_time));
#ifdef TIME_T_TYPE_DOUBLE
                        if ((ulg)(i_time) & (ulg)(0x80000000L)) {
                            if (ut_in_archive_sgn == -1)
                              z_utim->ctime =
                                (time_t)((long)i_time | (~(long)0x7fffffffL));
                            } else if (ut_in_archive_sgn == 1) {
                              z_utim->ctime =
                                (time_t)((ulg)i_time & (ulg)0xffffffffL);
                            } else {
                              /* sign of 32-bit time is unknown -> ignore it */
                              flags &= ~EB_UT_FL_CTIME;
                              TTrace((stderr,
                              "  UT creation time range error: skip time!\n"));
                            }
                        } else {
                            z_utim->ctime = (time_t)i_time;
                        }
#else /* !TIME_T_TYPE_DOUBLE */
                        if (((ulg)(i_time) & (ulg)(0x80000000L)) &&
                            !ut_zip_unzip_compatible) {
                            flags &= ~EB_UT_FL_CTIME;
                            TTrace((stderr,
                              "  UT creation time range error: skip time!\n"));
                        } else {
                            z_utim->ctime = (time_t)i_time;
                        }
#endif /* ?TIME_T_TYPE_DOUBLE */
                    } else {
                        flags &= ~EB_UT_FL_CTIME;
                    }
                }
            }
            break;

          case EF_IZUNIX2:
            if (!have_new_type_eb) {
                flags &= ~0x0ff;        /* ignore any previous IZUNIX field */
                have_new_type_eb = TRUE;
            }
            if (eb_len >= EB_UX2_MINLEN && z_uidgid != NULL) {
                z_uidgid[0] = makeword((EB_HEADSIZE+EB_UX2_UID) + ef_buf);
                z_uidgid[1] = makeword((EB_HEADSIZE+EB_UX2_GID) + ef_buf);
                flags |= EB_UX2_VALID;   /* signal success */
            }
            break;

          case EF_IZUNIX:
          case EF_PKUNIX:       /* PKUNIX e.f. layout is identical to IZUNIX */
            if (eb_len >= EB_UX_MINLEN) {
                TTrace((stderr,"ef_scan_for_izux: found %s extra field\n",
                        (eb_id == EF_IZUNIX ? "IZUNIX" : "PKUNIX")));
                if (have_new_type_eb) {
                    break;      /* Ignore IZUNIX extra field block ! */
                }
                if (z_utim != NULL) {
                    flags |= (EB_UT_FL_MTIME | EB_UT_FL_ATIME);
                    i_time = (long)makelong((EB_HEADSIZE+EB_UX_MTIME)+ef_buf);
                    TTrace((stderr,"  Unix EF modtime = %ld\n", i_time));
#ifdef TIME_T_TYPE_DOUBLE
                    if ((ulg)(i_time) & (ulg)(0x80000000L)) {
                        if (dos_mdatetime == DOSTIME_MINIMUM) {
                            ut_in_archive_sgn = -1;
                            z_utim->mtime =
                              (time_t)((long)i_time | (~(long)0x7fffffffL));
                        } else if (dos_mdatetime >= DOSTIME_2038_01_18) {
                            ut_in_archive_sgn = 1;
                            z_utim->mtime =
                              (time_t)((ulg)i_time & (ulg)0xffffffffL);
                        } else {
                            ut_in_archive_sgn = 0;
                            /* cannot determine sign of mtime;
                               without modtime: ignore complete UT field */
                            flags &= ~0x0ff;    /* no time_t times available */
                            TTrace((stderr,
                                  "  UX modtime range error: ignore e.f.!\n"));
                        }
                    } else {
                        /* cannot determine, safe assumption is FALSE */
                        ut_in_archive_sgn = 0;
                        z_utim->mtime = (time_t)i_time;
                    }
#else /* !TIME_T_TYPE_DOUBLE */
                    if ((ulg)(i_time) & (ulg)(0x80000000L)) {
                        ut_zip_unzip_compatible =
                          ((time_t)0x80000000L < (time_t)0L)
                          ? (dos_mdatetime == DOSTIME_MINIMUM)
                          : (dos_mdatetime >= DOSTIME_2038_01_18);
                        if (!ut_zip_unzip_compatible) {
                            /* UnZip interpretes mtime differently than Zip;
                               without modtime: ignore complete UT field */
                            flags &= ~0x0ff;    /* no time_t times available */
                            TTrace((stderr,
                                  "  UX modtime range error: ignore e.f.!\n"));
                        }
                    } else {
                        /* cannot determine, safe assumption is FALSE */
                        ut_zip_unzip_compatible = FALSE;
                    }
                    z_utim->mtime = (time_t)i_time;
#endif /* ?TIME_T_TYPE_DOUBLE */
                    i_time = (long)makelong((EB_HEADSIZE+EB_UX_ATIME)+ef_buf);
                    TTrace((stderr,"  Unix EF actime = %ld\n", i_time));
#ifdef TIME_T_TYPE_DOUBLE
                    if ((ulg)(i_time) & (ulg)(0x80000000L)) {
                        if (ut_in_archive_sgn == -1)
                            z_utim->atime =
                              (time_t)((long)i_time | (~(long)0x7fffffffL));
                        } else if (ut_in_archive_sgn == 1) {
                            z_utim->atime =
                              (time_t)((ulg)i_time & (ulg)0xffffffffL);
                        } else if (flags & 0x0ff) {
                            /* sign of 32-bit time is unknown -> ignore it */
                            flags &= ~EB_UT_FL_ATIME;
                            TTrace((stderr,
                                "  UX access time range error: skip time!\n"));
                        }
                    } else {
                        z_utim->atime = (time_t)i_time;
                    }
#else /* !TIME_T_TYPE_DOUBLE */
                    if (((ulg)(i_time) & (ulg)(0x80000000L)) &&
                        !ut_zip_unzip_compatible && (flags & 0x0ff)) {
                        /* atime not in range of UnZip's time_t */
                        flags &= ~EB_UT_FL_ATIME;
                        TTrace((stderr,
                                "  UX access time range error: skip time!\n"));
                    } else {
                        z_utim->atime = (time_t)i_time;
                    }
#endif /* ?TIME_T_TYPE_DOUBLE */
                }
                if (eb_len >= EB_UX_FULLSIZE && z_uidgid != NULL) {
                    z_uidgid[0] = makeword((EB_HEADSIZE+EB_UX_UID) + ef_buf);
                    z_uidgid[1] = makeword((EB_HEADSIZE+EB_UX_GID) + ef_buf);
                    flags |= EB_UX2_VALID;
                }
            }
            break;

          default:
            break;
        }

        /* Skip this extra field block */
        ef_buf += (eb_len + EB_HEADSIZE);
        ef_len -= (eb_len + EB_HEADSIZE);
    }

    return flags;
}

#endif /* USE_EF_UT_TIME */


#if (defined(RISCOS) || defined(ACORN_FTYPE_NFS))

#define SPARKID_2 0x30435241    /* = "ARC0" */

/*******************************/
/* Function getRISCOSexfield() */
/*******************************/

zvoid *getRISCOSexfield(ef_buf, ef_len)
    ZCONST uch *ef_buf; /* buffer containing extra field */
    unsigned ef_len;    /* total length of extra field */
{
    unsigned eb_id;
    unsigned eb_len;

/*---------------------------------------------------------------------------
    This function scans the extra field for a Acorn SPARK filetype ef-block.
    If a valid block is found, the function returns a pointer to the start
    of the SPARK_EF block in the extra field buffer.  Otherwise, a NULL
    pointer is returned.
  ---------------------------------------------------------------------------*/

    if (ef_len == 0 || ef_buf == NULL)
        return NULL;

    TTrace((stderr,"\ngetRISCOSexfield: scanning extra field of length %u\n",
      ef_len));

    while (ef_len >= EB_HEADSIZE) {
        eb_id = makeword(EB_ID + ef_buf);
        eb_len = makeword(EB_LEN + ef_buf);

        if (eb_len > (ef_len - EB_HEADSIZE)) {
            /* discovered some extra field inconsistency! */
            TTrace((stderr,
              "getRISCOSexfield: block length %u > rest ef_size %u\n", eb_len,
              ef_len - EB_HEADSIZE));
            break;
        }

        if (eb_id == EF_SPARK && (eb_len == 24 || eb_len == 20)) {
            if (makelong(EB_HEADSIZE + ef_buf) == SPARKID_2) {
                /* Return a pointer to the valid SPARK filetype ef block */
                return (zvoid *)ef_buf;
            }
        }

        /* Skip this extra field block */
        ef_buf += (eb_len + EB_HEADSIZE);
        ef_len -= (eb_len + EB_HEADSIZE);
    }

    return NULL;
}

#endif /* (RISCOS || ACORN_FTYPE_NFS) */