om@2: /*
om@2:  * main.cpp
om@2:  * 
om@2:  * This is the shadowfuse main startup file.
om@2:  *
om@2:  * Autor: Oliver Maurhart, <oliver.maurhart@ait.ac.at>
om@2:  *
om@2:  * Copyright (C) 2013 AIT Austrian Institute of Technology
om@2:  * AIT Austrian Institute of Technology GmbH
om@2:  * Donau-City-Strasse 1 | 1220 Vienna | Austria
om@2:  * http://www.ait.ac.at
om@2:  *
om@2:  * This program is free software; you can redistribute it and/or
om@2:  * modify it under the terms of the GNU General Public License
om@2:  * as published by the Free Software Foundation version 2.
om@2:  * 
om@2:  * This program is distributed in the hope that it will be useful,
om@2:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
om@2:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
om@2:  * GNU General Public License for more details.
om@2:  * 
om@2:  * You should have received a copy of the GNU General Public License
om@2:  * along with this program; if not, write to the Free Software
om@2:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, 
om@2:  * Boston, MA  02110-1301, USA.
om@2:  */
om@2: 
om@2:  
om@2: // ------------------------------------------------------------
om@2: // incs
om@2: 
om@2: #include "baseinc.h"
om@2: 
om@2: 
om@2: // ------------------------------------------------------------
om@2: // defs
om@2: 
om@2: 
om@2: /**
om@2:  * shadowfuse version
om@2:  */
om@2: #define SHADOWFUSE_VERSION  "0.1"
om@2: 
om@2: 
om@2: // ------------------------------------------------------------
om@2: // vars
om@2: 
om@2: 
om@2: /**
om@2:  * keys for FUSE_OPT_ options 
om@2:  */
om@2: enum {
om@2:    KEY_VERSION,
om@2:    KEY_HELP,
om@2: };
om@2: 
om@2: 
om@2: /**
om@2:  * array of options we know
om@2:  */
om@2: static struct fuse_opt shadowfuse_opts[] = {
om@2:     FUSE_OPT_KEY("-V",             KEY_VERSION),
om@2:     FUSE_OPT_KEY("--version",      KEY_VERSION),
om@2:     FUSE_OPT_KEY("-h",             KEY_HELP),
om@2:     FUSE_OPT_KEY("--help",         KEY_HELP),
om@2:     FUSE_OPT_END
om@2: };
om@2: 
om@2: 
om@2: /**
om@2:  * configuration of shadowfuse
om@2:  */
om@2: static struct shadowfuse_config {
om@2: 
om@2:     std::string sShadowedPath;
om@2:     std::string sMountPoint;
om@2:     
om@2:     /**
om@2:      * check for paths been set
om@2:      */
om@2:     inline bool is_paths_set() const { return !(sShadowedPath.empty() || sMountPoint.empty()); };
om@2:     
om@2: } g_cShadowFuseConfig;
om@2: 
om@2: 
om@2: // ------------------------------------------------------------
om@2: // fwd
om@2: 
om@2: static int option_processor(void * cData, const char * sArg, int nKey, struct fuse_args * cOutArgs);
om@2: static void usage(const char * sProgName);
om@2: 
om@2: 
om@2: // ------------------------------------------------------------
om@2: // code
om@2: 
om@2: 
om@2: 
om@2: /** 
om@2:  * get file attributes.
om@2:  */
om@2: static int shadow_getattr(const char * sPath, struct stat * cFileStat) {
om@2:     
om@2:     // open the shadow file
om@2:     std::string sShadow = g_cShadowFuseConfig.sShadowedPath + sPath;
om@2: std::cerr << "=== INSERT HOOK HERE. Getting file attributes of " << sShadow << std::endl;
om@2: 
om@2:     memset(cFileStat, 0, sizeof(struct stat));
om@2:     if (stat(sShadow.c_str(), cFileStat) == -1) return -errno;
om@2:     
om@2:     return 0;
om@2: }
om@2: 
om@2: 
om@2: 
om@2: /** 
om@2:  * create a directory 
om@2:  */
om@2: static int shadow_mkdir(const char * sPath, mode_t cMode) {
om@2:     
om@2:     // create directory
om@2:     std::string sShadow = g_cShadowFuseConfig.sShadowedPath + sPath;
om@2: std::cerr << "=== INSERT HOOK HERE. Create directory " << sShadow << std::endl;
om@2: 
om@2:     if (mkdir(sShadow.c_str(), cMode) == -1) return -errno;
om@2:     return 0;
om@2: }
om@2: 
om@2: 
om@2: /** 
om@2:  * create a file
om@2:  */
om@2: static int shadow_mknod(const char * sPath, mode_t cMode, dev_t cDev) {
om@2:     
om@2:     // create file
om@2:     std::string sShadow = g_cShadowFuseConfig.sShadowedPath + sPath;
om@2: std::cerr << "=== INSERT HOOK HERE. Create file " << sShadow << std::endl;
om@2: 
om@2:     if (mknod(sShadow.c_str(), cMode, cDev) == -1) return -errno;
om@2:     return 0;
om@2: }
om@2: 
om@2: 
om@2: /**
om@2:  * open file
om@2:  */
om@2: static int shadow_open(const char * sPath, struct fuse_file_info * cFileInfo) {
om@2:     
om@2:     // open the shadow file
om@2:     std::string sShadow = g_cShadowFuseConfig.sShadowedPath + sPath;
om@2: std::cerr << "=== INSERT HOOK HERE. Opening file " << sShadow << std::endl;
om@2: 
om@2:     if (open(sShadow.c_str(), cFileInfo->flags) == -1) return -errno;
om@2:     return 0;
om@2: }
om@2: 
om@2: 
om@2: /**
om@2:  * read from file
om@2:  */
om@2: static int shadow_read(const char * sPath, char * cBuffer, size_t nSize, off_t nOffset, UNUSED struct fuse_file_info * cFileInfo) {
om@2:     
om@2:     // read from shadow file
om@2:     std::string sShadow = g_cShadowFuseConfig.sShadowedPath + sPath;
om@2: std::cerr << "=== INSERT HOOK HERE. Reading file " << sShadow << " [offset=" << nOffset << ", fetch max bytes=" << nSize << "]" << std::endl;
om@2: 
om@2:     // open, pick bytes, close & out
om@2:     int fd = open(sShadow.c_str(), O_RDONLY);
om@2:     if (fd == -1) return -errno;
om@2:     int res = pread(fd, cBuffer, nSize, nOffset);
om@2:     if (res == -1) res = -errno;
om@2:     close(fd);
om@2:     
om@2:     return res;
om@2: }
om@2: 
om@2: 
om@2: /**
om@2:  * read directory
om@2:  */
om@2: static int shadow_readdir(const char * sPath, void * cBuffer, fuse_fill_dir_t fFiller, UNUSED off_t nOffset, UNUSED struct fuse_file_info * cFileInfo) {
om@2: 
om@2:     DIR * cDIR;
om@2:     struct dirent * cDirEntry;
om@2:     int res = 0;
om@2: 
om@2:     // open the shadow folder
om@2:     std::string sShadow = g_cShadowFuseConfig.sShadowedPath + sPath;
om@2: std::cerr << "=== INSERT HOOK HERE. Reading content of " << sShadow << std::endl;
om@2:     
om@2:     cDIR = opendir(sShadow.c_str());
om@2:     if (!cDIR) return -errno;
om@2: 
om@2:     // walk over the entries
om@2:     while ((cDirEntry = readdir(cDIR)) != NULL) {
om@2:         
om@2:         // pick file stat as well
om@2:         struct stat cFileStat;
om@2:         stat(sShadow.c_str(), &cFileStat);
om@2:         res = fFiller(cBuffer, cDirEntry->d_name, &cFileStat, 0);
om@2:          if (res != 0) break;
om@2:     }
om@2: 
om@2:     // free directory
om@2:     closedir(cDIR);
om@2:     return res;
om@2: }
om@2: 
om@2: 
om@2: /**
om@2:  * move file
om@2:  */
om@2: static int shadow_rename(const char * sFromPath, const char * sToPath) {
om@2:     
om@2:     // move file
om@2:     std::string sShadowFrom = g_cShadowFuseConfig.sShadowedPath + sFromPath;
om@2:     std::string sShadowTo = g_cShadowFuseConfig.sShadowedPath + sToPath;
om@2: std::cerr << "=== INSERT HOOK HERE. Moving file from " << sShadowFrom << " to " << sShadowTo << std::endl;
om@2: 
om@2:     if (rename(sShadowFrom.c_str(), sShadowTo.c_str()) == -1) return -errno;
om@2:     return 0;
om@2: }
om@2: 
om@2: 
om@2: /**
om@2:  * delete a folder
om@2:  */
om@2: static int shadow_rmdir(const char * sPath) {
om@2:     
om@2:     // delete the shadow folder
om@2:     std::string sShadow = g_cShadowFuseConfig.sShadowedPath + sPath;
om@2: std::cerr << "=== INSERT HOOK HERE. Delete folder " << sShadow << std::endl;
om@2: 
om@2:     if (rmdir(sShadow.c_str()) == -1) return -errno;
om@2:     return 0;
om@2: }
om@2: 
om@2: 
om@2: /**
om@2:  * delete a file
om@2:  */
om@2: static int shadow_unlink(const char * sPath) {
om@2:     
om@2:     // delete the shadow file
om@2:     std::string sShadow = g_cShadowFuseConfig.sShadowedPath + sPath;
om@2: std::cerr << "=== INSERT HOOK HERE. Delete file " << sShadow << std::endl;
om@2: 
om@2:     if (unlink(sShadow.c_str()) == -1) return -errno;
om@2:     return 0;
om@2: }
om@2: 
om@2: 
om@2: /**
om@2:  * write int file
om@2:  */
om@2: static int shadow_write(const char * sPath, const char * cBuffer, size_t nSize, off_t nOffset, UNUSED struct fuse_file_info * cFileInfo) {
om@2:     
om@2:     // write into file
om@2:     std::string sShadow = g_cShadowFuseConfig.sShadowedPath + sPath;
om@2: std::cerr << "=== INSERT HOOK HERE. Write into file " << sShadow << std::endl;
om@2: 
om@2:     // open, push bytes, close & out
om@2:     int fd = open(sShadow.c_str(), O_WRONLY);
om@2:     if (fd == -1) return -errno;
om@2:     int res = pwrite(fd, cBuffer, nSize, nOffset);
om@2:     if (res == -1) res = -errno;
om@2:     close(fd);
om@2:     
om@2:     return res;
om@2: }
om@2: 
om@2: 
om@2: /**
om@2:  * the shadowfuse function table
om@2:  */
om@2: static struct fuse_operations shadowfuse_operations {
om@2:     
om@2:     shadow_getattr,     // getattr
om@2:     nullptr,            // readlink
om@2:     nullptr,            // getdir
om@2:     shadow_mknod,       // mknod
om@2:     shadow_mkdir,       // mkdir
om@2:     shadow_unlink,      // unlink
om@2:     shadow_rmdir,       // rmdir
om@2:     nullptr,            // symlink
om@2:     shadow_rename,      // rename
om@2:     nullptr,            // link
om@2:     nullptr,            // chmod
om@2:     nullptr,            // chown
om@2:     nullptr,            // truncate
om@2:     nullptr,            // utime
om@2:     shadow_open,        // open
om@2:     shadow_read,        // read
om@2:     shadow_write,       // write
om@2:     nullptr,            // statfs
om@2:     nullptr,            // flush
om@2:     nullptr,            // release
om@2:     nullptr,            // fsync
om@2:     nullptr,            // setxattr
om@2:     nullptr,            // getxattr
om@2:     nullptr,            // listxattr
om@2:     nullptr,            // removexattr
om@2:     nullptr,            // opendir
om@2:     shadow_readdir,     // readdir
om@2:     nullptr,            // releasedir
om@2:     nullptr,            // fsyncdir
om@2:     nullptr,            // init
om@2:     nullptr,            // destroy
om@2:     nullptr,            // access
om@2:     nullptr,            // create
om@2:     nullptr,            // ftruncate
om@2:     nullptr,            // fgetattr
om@2:     nullptr,            // lock
om@2:     nullptr,            // utimens
om@2:     nullptr,            // bmap
om@2:     0,                  // flag_nullpath_ok
om@2:     0,                  // flag_nopath
om@2:     0,                  // flag_utime_omit_ok
om@2:     0,                  // flag_reserved
om@2:     nullptr,            // ioctl
om@2:     nullptr,            // poll
om@2:     nullptr,            // write_buf
om@2:     nullptr,            // read_buf
om@2:     nullptr,            // flock
om@2:     nullptr             // fallocate
om@2: };
om@2: 
om@2: 
om@2: /**
om@2:  * start
om@2:  * 
om@2:  * @param   argc        as usual
om@2:  * @param   argv        as usual
om@2:  * @return  as usual
om@2:  */
om@2: int main(int argc, char ** argv) {
om@2:     
om@2:     // option parsing
om@2:     struct fuse_args cFUSEArgs = FUSE_ARGS_INIT(argc, argv);
om@2:     if (fuse_opt_parse(&cFUSEArgs, NULL, shadowfuse_opts, option_processor) == -1) {
om@2:         return -1;
om@2:     }
om@2:     
om@2:     // test if our config is setup ok
om@2:     if (!g_cShadowFuseConfig.is_paths_set()) {
om@2:         std::cerr << "sourcefolder and/or mount point not given" << std::endl;
om@2:         exit(1);
om@2:     }
om@2: 
om@2:     // do FUSE
om@2:     int ret = fuse_main(cFUSEArgs.argc, cFUSEArgs.argv, &shadowfuse_operations, NULL);
om@2:     if (ret) printf("\n");
om@2:     fuse_opt_free_args(&cFUSEArgs);
om@2:         
om@2:     return ret;
om@2: }
om@2: 
om@2: 
om@2: /**
om@2:  * option parser processor
om@2:  * 
om@2:  * @param   cData       is the user data passed to the fuse_opt_parse() function
om@2:  * @param   sArg        is the whole argument or option
om@2:  * @param   nKey        determines why the processing function was called
om@2:  * @param   cOutArgs    the current output argument list
om@2:  * @return  -1 on error, 0 if arg is to be discarded, 1 if arg should be kept
om@2:  */
om@2: static int option_processor(UNUSED void * cData, UNUSED const char * sArg, int nKey, struct fuse_args * cOutArgs) {
om@2: 
om@2:     // select by key
om@2:     switch (nKey) {
om@2:         
om@2:     case FUSE_OPT_KEY_OPT:
om@2:         return 1;
om@2: 
om@2:     case FUSE_OPT_KEY_NONOPT:
om@2:         // the non-options
om@2:         if (g_cShadowFuseConfig.sShadowedPath.empty()) {
om@2:             // first non-option is the path to be shadowed
om@2:             g_cShadowFuseConfig.sShadowedPath = sArg;
om@2:             return 0;
om@2:         }
om@2:         else
om@2:         if (g_cShadowFuseConfig.sMountPoint.empty()) {
om@2:             // the mount point
om@2:             g_cShadowFuseConfig.sMountPoint = sArg;
om@2:             return 1;
om@2:         }
om@2:         return 1;
om@2: 
om@2:     case KEY_HELP:
om@2:         usage(cOutArgs->argv[0]);
om@2:         exit(1);
om@2: 
om@2:     case KEY_VERSION:
om@2:         printf("shadowfuse version %s\n", SHADOWFUSE_VERSION);
om@2:         exit(0);
om@2: 
om@2:     default:
om@2:         fprintf(stderr, "internal error\n");
om@2:         abort();
om@2:     }
om@2: }
om@2: 
om@2: 
om@2: /**
om@2:  * print usage
om@2:  * 
om@2:  * @param   sProgName       name of the current program
om@2:  */
om@2: static void usage(const char * sProgName) {
om@2:     printf(
om@2: "usage: %s sourcefolder mountpoint\n"
om@2: "\n"
om@2: "general options:\n"
om@2: "    -f                     foreground\n"
om@2: "    -d   -odebug           foreground, but keep the debug option\n"
om@2: "    -h   --help            print help\n"
om@2: "    -V   --version         print version\n"
om@2: "\n", sProgName);
om@2: }
om@2: