/*

  *  Copyright (C) 2013-2019 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
  *  Copyright (C) 2009-2013 Sourcefire, Inc.

  *
  *  Authors: Tomasz Kojm <tkojm@clamav.net>
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License version 2 as
  *  published by the Free Software Foundation.
  *
  *  This program 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 for more details.
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program; if not, write to the Free Software
  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  *  MA 02110-1301, USA.
  */
 
 #if HAVE_CONFIG_H
 #include "clamav-config.h"
 #endif
 
 #include <stdio.h>
 #include <string.h>
 #include <ctype.h>

 #ifdef HAVE_UNISTD_H

 #include <unistd.h>

 #endif

 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 

 #include "clamav.h"

 #include "others.h"
 #include "cpio.h"
 #include "scanners.h"

 #include "matcher.h"

 
 struct cpio_hdr_old {
     uint16_t magic;
     uint16_t dev;
     uint16_t ino;
     uint16_t mode;
     uint16_t uid;
     uint16_t gid;
     uint16_t nlink;
     uint16_t rdev;
     uint16_t mtime[2];
     uint16_t namesize;
     uint16_t filesize[2];
 };
 
 struct cpio_hdr_odc {
     char magic[6];
     char dev[6];
     char ino[6];
     char mode[6];
     char uid[6];
     char gid[6];
     char nlink[6];
     char rdev[6];
     char mtime[11];
     char namesize[6];
     char filesize[11];
 };
 
 struct cpio_hdr_newc {
     char magic[6];
     char ino[8];
     char mode[8];
     char uid[8];
     char gid[8];
     char nlink[8];
     char mtime[8];
     char filesize[8];
     char devmajor[8];
     char devminor[8];
     char rdevmajor[8];
     char rdevminor[8];
     char namesize[8];
     char check[8];
 };
 

 #define EC16(v, conv) (conv ? cbswap16(v) : v)

 
 static void sanitname(char *name)
 {

     while (*name) {
         if (!isascii(*name) || strchr("%\\\t\n\r", *name))
             *name = '_';
         name++;

     }
 }
 

 int cli_scancpio_old(cli_ctx *ctx)

 {

     struct cpio_hdr_old hdr_old;
     char name[513];
     unsigned int file = 0, trailer = 0;
     uint32_t filesize, namesize, hdr_namesize;
     int ret         = CL_CLEAN, conv;
     off_t pos       = 0;
     int virus_found = 0;
 
     while (fmap_readn(*ctx->fmap, &hdr_old, pos, sizeof(hdr_old)) == sizeof(hdr_old)) {
         pos += sizeof(hdr_old);
         if (!hdr_old.magic && trailer) {

             ret = CL_SUCCESS;

             goto leave;

         }

         if (hdr_old.magic == 070707) {
             conv = 0;
         } else if (hdr_old.magic == 0143561) {
             conv = 1;
         } else {
             cli_dbgmsg("cli_scancpio_old: Invalid magic number\n");
             ret = CL_EFORMAT;

             goto leave;

         }
 
         cli_dbgmsg("CPIO: -- File %u --\n", ++file);
 
         if (hdr_old.namesize) {
             hdr_namesize = EC16(hdr_old.namesize, conv);
             namesize     = MIN(sizeof(name), hdr_namesize);

             if (fmap_readn(*ctx->fmap, &name, pos, namesize) != namesize) {

                 cli_dbgmsg("cli_scancpio_old: Can't read file name\n");
                 return CL_EFORMAT;
             }
             pos += namesize;
             name[namesize - 1] = 0;
             sanitname(name);
             cli_dbgmsg("CPIO: Name: %s\n", name);
             if (!strcmp(name, "TRAILER!!!"))
                 trailer = 1;
 
             if (namesize < hdr_namesize) {
                 if (hdr_namesize % 2)
                     hdr_namesize++;
                 pos += hdr_namesize - namesize;
             } else if (hdr_namesize % 2)
                 pos++;
         }

         filesize = (uint32_t)((uint32_t)EC16(hdr_old.filesize[0], conv) << 16 | EC16(hdr_old.filesize[1], conv));

         cli_dbgmsg("CPIO: Filesize: %u\n", filesize);
         if (!filesize)
             continue;
 
         if (cli_matchmeta(ctx, name, filesize, filesize, 0, file, 0, NULL) == CL_VIRUS) {

             if (!SCAN_ALLMATCHES)

                 return CL_VIRUS;
             virus_found = 1;
         }

         if ((EC16(hdr_old.mode, conv) & 0170000) != 0100000) {
             cli_dbgmsg("CPIO: Not a regular file, skipping\n");
         } else {
             ret = cli_checklimits("cli_scancpio_old", ctx, filesize, 0, 0);
             if (ret == CL_EMAXFILES) {
                 goto leave;
             } else if (ret == CL_SUCCESS) {
                 ret = cli_map_scan(*ctx->fmap, pos, filesize, ctx, CL_TYPE_ANY);
                 if (ret == CL_VIRUS) {

                     if (!SCAN_ALLMATCHES)

                         return ret;
                     virus_found = 1;
                 }

             }
         }
         if (filesize % 2)
             filesize++;

         pos += filesize;

     }
 

 leave:

     if (virus_found != 0)
         return CL_VIRUS;
     return ret;

 }
 

 int cli_scancpio_odc(cli_ctx *ctx)

 {

     struct cpio_hdr_odc hdr_odc;
     char name[513], buff[12];
     unsigned int file = 0, trailer = 0;
     uint32_t filesize, namesize, hdr_namesize;
     int ret         = CL_CLEAN;
     off_t pos       = 0;
     int virus_found = 0;
 
     while (fmap_readn(*ctx->fmap, &hdr_odc, pos, sizeof(hdr_odc)) == sizeof(hdr_odc)) {
         pos += sizeof(hdr_odc);
         if (!hdr_odc.magic[0] && trailer)
             goto leave;
 
         if (strncmp(hdr_odc.magic, "070707", 6)) {
             cli_dbgmsg("cli_scancpio_odc: Invalid magic string\n");
             ret = CL_EFORMAT;

             goto leave;

         }

         cli_dbgmsg("CPIO: -- File %u --\n", ++file);

         strncpy(buff, hdr_odc.namesize, 6);
         buff[6] = 0;
         if (sscanf(buff, "%o", &hdr_namesize) != 1) {
             cli_dbgmsg("cli_scancpio_odc: Can't convert name size\n");
             ret = CL_EFORMAT;

             goto leave;

         }
         if (hdr_namesize) {
             namesize = MIN(sizeof(name), hdr_namesize);

             if (fmap_readn(*ctx->fmap, &name, pos, namesize) != namesize) {

                 cli_dbgmsg("cli_scancpio_odc: Can't read file name\n");
                 ret = CL_EFORMAT;

                 goto leave;

             }
             pos += namesize;
             name[namesize - 1] = 0;
             sanitname(name);
             cli_dbgmsg("CPIO: Name: %s\n", name);
             if (!strcmp(name, "TRAILER!!!"))
                 trailer = 1;
 
             if (namesize < hdr_namesize)
                 pos += hdr_namesize - namesize;
         }
 
         strncpy(buff, hdr_odc.filesize, 11);
         buff[11] = 0;
         if (sscanf(buff, "%o", &filesize) != 1) {
             cli_dbgmsg("cli_scancpio_odc: Can't convert file size\n");
             ret = CL_EFORMAT;

             goto leave;

         }
         cli_dbgmsg("CPIO: Filesize: %u\n", filesize);
         if (!filesize)
             continue;

         if (cli_matchmeta(ctx, name, filesize, filesize, 0, file, 0, NULL) == CL_VIRUS) {

             if (!SCAN_ALLMATCHES)

                 return CL_VIRUS;
             virus_found = 1;
         }

         ret = cli_checklimits("cli_scancpio_odc", ctx, filesize, 0, 0);
         if (ret == CL_EMAXFILES) {
             goto leave;
         } else if (ret == CL_SUCCESS) {
             ret = cli_map_scan(*ctx->fmap, pos, filesize, ctx, CL_TYPE_ANY);
             if (ret == CL_VIRUS) {

                 if (!SCAN_ALLMATCHES)

                     return ret;
                 virus_found = 1;
             }

         }

         pos += filesize;

     }
 

 leave:

     if (virus_found != 0)
         return CL_VIRUS;
     return ret;

 }
 

 int cli_scancpio_newc(cli_ctx *ctx, int crc)

 {

     struct cpio_hdr_newc hdr_newc;
     char name[513], buff[9];
     unsigned int file = 0, trailer = 0;
     uint32_t filesize, namesize, hdr_namesize, pad;
     int ret         = CL_CLEAN;
     off_t pos       = 0;
     int virus_found = 0;

     memset(name, 0, 513);

     while (fmap_readn(*ctx->fmap, &hdr_newc, pos, sizeof(hdr_newc)) == sizeof(hdr_newc)) {
         pos += sizeof(hdr_newc);
         if (!hdr_newc.magic[0] && trailer)
             goto leave;

         if ((!crc && strncmp(hdr_newc.magic, "070701", 6)) || (crc && strncmp(hdr_newc.magic, "070702", 6))) {
             cli_dbgmsg("cli_scancpio_newc: Invalid magic string\n");
             ret = CL_EFORMAT;

             goto leave;

         }

         cli_dbgmsg("CPIO: -- File %u --\n", ++file);

         strncpy(buff, hdr_newc.namesize, 8);
         buff[8] = 0;
         if (sscanf(buff, "%x", &hdr_namesize) != 1) {
             cli_dbgmsg("cli_scancpio_newc: Can't convert name size\n");
             ret = CL_EFORMAT;

             goto leave;

         }
         if (hdr_namesize) {
             namesize = MIN(sizeof(name), hdr_namesize);

             if (fmap_readn(*ctx->fmap, &name, pos, namesize) != namesize) {

                 cli_dbgmsg("cli_scancpio_newc: Can't read file name\n");
                 ret = CL_EFORMAT;

                 goto leave;

             }
             pos += namesize;
             name[namesize - 1] = 0;
             sanitname(name);
             cli_dbgmsg("CPIO: Name: %s\n", name);
             if (!strcmp(name, "TRAILER!!!"))
                 trailer = 1;
 
             pad = (4 - (sizeof(hdr_newc) + hdr_namesize) % 4) % 4;
             if (namesize < hdr_namesize) {
                 if (pad)
                     hdr_namesize += pad;
                 pos += hdr_namesize - namesize;
             } else if (pad)
                 pos += pad;
         }
 
         strncpy(buff, hdr_newc.filesize, 8);
         buff[8] = 0;
         if (sscanf(buff, "%x", &filesize) != 1) {
             cli_dbgmsg("cli_scancpio_newc: Can't convert file size\n");
             ret = CL_EFORMAT;

             goto leave;

         }
         cli_dbgmsg("CPIO: Filesize: %u\n", filesize);
         if (!filesize)
             continue;

         if (cli_matchmeta(ctx, name, filesize, filesize, 0, file, 0, NULL) == CL_VIRUS) {

             if (!SCAN_ALLMATCHES)

                 return CL_VIRUS;
             virus_found = 1;
         }

         ret = cli_checklimits("cli_scancpio_newc", ctx, filesize, 0, 0);
         if (ret == CL_EMAXFILES) {
             goto leave;
         } else if (ret == CL_SUCCESS) {
             ret = cli_map_scan(*ctx->fmap, pos, filesize, ctx, CL_TYPE_ANY);
             if (ret == CL_VIRUS) {

                 if (!SCAN_ALLMATCHES)

                     return ret;
                 virus_found = 1;
             }

         }

         if ((pad = filesize % 4))
             filesize += (4 - pad);

         pos += filesize;

     }
 

 leave:

     if (virus_found != 0)
         return CL_VIRUS;
     return ret;

 }