Removed a potential buffer overflow and factorized some code

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@3742 d7cf8633-e32d-0410-b094-e92efae38249

diff --git a/fs.c b/fs.c
index 4b36f512283a06788b374e18207ccdb119a3df2f..8a4ade50786e113def681ef0181a61cede96eed8 100644 (file)
--- a/fs.c
+++ b/fs.c
@@ -231,6 +231,22 @@ typedef struct searchpath_s
 } searchpath_t;
 
 
+/*
+=============================================================================
+
+FUNCTION PROTOTYPES
+
+=============================================================================
+*/
+
+void FS_Dir_f(void);
+void FS_Ls_f(void);
+
+static packfile_t* FS_AddFileToPack (const char* name, pack_t* pack,
+                                                                        size_t offset, size_t packsize,
+                                                                        size_t realsize, file_flags_t flags);
+
+
 /*
 =============================================================================
 
@@ -447,7 +463,6 @@ int PK3_BuildFileList (pack_t *pack, const pk3_endOfCentralDir_t *eocd)
        for (ind = 0; ind < eocd->nbentries; ind++)
        {
                size_t namesize, count;
-               packfile_t *file;
 
                // Checking the remaining size
                if (remaining < ZIP_CDIR_CHUNK_BASE_SIZE)
@@ -483,19 +498,24 @@ int PK3_BuildFileList (pack_t *pack, const pk3_endOfCentralDir_t *eocd)
                        // WinZip doesn't use the "directory" attribute, so we need to check the name directly
                        if (ptr[ZIP_CDIR_CHUNK_BASE_SIZE + namesize - 1] != '/')
                        {
-                               // Extract the name
-                               file = &pack->files[pack->numfiles];
-                               memcpy (file->name, &ptr[ZIP_CDIR_CHUNK_BASE_SIZE], namesize);
-                               file->name[namesize] = '\0';
+                               char filename [sizeof (pack->files[0].name)];
+                               size_t offset, packsize, realsize;
+                               file_flags_t flags;
 
-                               // Compression, sizes and offset
-                               if (BuffLittleShort (&ptr[10]))
-                                       file->flags = FILE_FLAG_DEFLATED;
-                               file->packsize = BuffLittleLong (&ptr[20]);
-                               file->realsize = BuffLittleLong (&ptr[24]);
-                               file->offset = BuffLittleLong (&ptr[42]);
+                               // Extract the name (strip it if necessary)
+                               if (namesize >= sizeof (filename))
+                                       namesize = sizeof (filename) - 1;
+                               memcpy (filename, &ptr[ZIP_CDIR_CHUNK_BASE_SIZE], namesize);
+                               filename[namesize] = '\0';
 
-                               pack->numfiles++;
+                               if (BuffLittleShort (&ptr[10]))
+                                       flags = FILE_FLAG_DEFLATED;
+                               else
+                                       flags = 0;
+                               offset = BuffLittleLong (&ptr[42]);
+                               packsize = BuffLittleLong (&ptr[20]);
+                               realsize = BuffLittleLong (&ptr[24]);
+                               FS_AddFileToPack (filename, pack, offset, packsize, realsize, flags);
                        }
                }
 
@@ -602,6 +622,31 @@ OTHER PRIVATE FUNCTIONS
 */
 
 
+/*
+====================
+FS_AddFileToPack
+
+Add a file to the list of files contained into a package 
+
+TODO: do some sorting here to allow faster file searching afterwards
+====================
+*/
+static packfile_t* FS_AddFileToPack (const char* name, pack_t* pack,
+                                                                        size_t offset, size_t packsize,
+                                                                        size_t realsize, file_flags_t flags)
+{
+       packfile_t *file = &pack->files[pack->numfiles++];
+
+       strlcpy (file->name, name, sizeof (file->name));
+       file->offset = offset;
+       file->packsize = packsize;
+       file->realsize = realsize;
+       file->flags = flags;
+
+       return file;
+}
+
+
 /*
 ============
 FS_CreatePath
@@ -690,7 +735,7 @@ pack_t *FS_LoadPackPAK (const char *packfile)
        pack->ignorecase = false; // PAK is case sensitive
        strlcpy (pack->filename, packfile, sizeof (pack->filename));
        pack->handle = packhandle;
-       pack->numfiles = numpackfiles;
+       pack->numfiles = 0;
        pack->mempool = Mem_AllocPool(packfile);
        pack->files = Mem_Alloc(pack->mempool, numpackfiles * sizeof(packfile_t));
        pack->next = packlist;
@@ -703,15 +748,10 @@ pack_t *FS_LoadPackPAK (const char *packfile)
        // parse the directory
        for (i = 0;i < numpackfiles;i++)
        {
-               size_t size;
-               packfile_t *file = &pack->files[i];
-
-               strlcpy (file->name, info[i].name, sizeof (file->name));
-               file->offset = LittleLong(info[i].filepos);
-               size = LittleLong (info[i].filelen);
-               file->packsize = size;
-               file->realsize = size;
-               file->flags = FILE_FLAG_TRUEOFFS;
+               size_t offset = LittleLong (info[i].filepos);
+               size_t size = LittleLong (info[i].filelen);
+
+               FS_AddFileToPack (info[i].name, pack, offset, size, size, FILE_FLAG_TRUEOFFS);
        }
 
        Mem_Free(info);
@@ -827,8 +867,6 @@ char *FS_FileExtension (const char *in)
        return exten;
 }
 
-void FS_Dir_f(void);
-void FS_Ls_f(void);
 
 /*
 ================