implemented filesystem provider

src/provider_main.cpp

@@ -2,6 +2,7 @@
 #include "webfuse/version.hpp"
 
 #include <unistd.h>
+#include <fcntl.h>
 #include <sys/stat.h>
 #include <dirent.h>
 
@@ -120,9 +121,22 @@ class filesystem: public webfuse::filesystem_i
 {
 public:
     explicit filesystem(std::string const & base_path)
-    : base_path_(base_path)
     {
+        char buffer[PATH_MAX];
+        char * resolved_path = ::realpath(base_path.c_str(), buffer);
+        if (nullptr == resolved_path)
+        {
+            throw std::runtime_error("failed to resolve path");
+        }
 
+        struct stat info;
+        int const rc = stat(resolved_path, &info);
+        if (!S_ISDIR(info.st_mode))
+        {
+            throw std::runtime_error("path is not a directory");
+        }
+
+        base_path_ = resolved_path;
     }
 
     ~filesystem() override
@@ -133,7 +147,6 @@ public:
     int access(std::string const & path, int mode) override
     {
         auto const full_path = get_full_path(path);
-        std::cout << "access: " << full_path << std::endl;
 
         auto const result = ::access(full_path.c_str(), mode);
         return (result == 0) ? 0 : -errno;
@@ -142,7 +155,6 @@ public:
     int getattr(std::string const & path, struct stat * attr) override
     {
         auto const full_path = get_full_path(path);
-        std::cout << "getattr: " << full_path << std::endl;
 
         auto const result = lstat(full_path.c_str(), attr);
         return (result == 0) ? 0 : -errno;
@@ -150,93 +162,219 @@ public:
 
     int readlink(std::string const & path, std::string & out) override
     {
-        return -ENOENT;
+        auto const full_path = get_full_path(path);
+
+        char buffer[PATH_MAX];
+        int const result = ::readlink(full_path.c_str(), buffer, PATH_MAX);
+        if ((0 <= result) && (result < PATH_MAX))
+        {
+            buffer[result] = '\0';
+            out = buffer;
+        }
+
+        return (result >= 0) ? 0 : -errno;
     }
     
-    int symlink(std::string const & target, std::string const & linkpath) override
+    int symlink(std::string const & from, std::string const & to) override
     {
-        return -ENOENT;
+        auto const full_from = ('/' == from.at(0)) ? get_full_path(from) : from;
+        auto const full_to = get_full_path(to);
+
+        int const result = ::symlink(full_from.c_str(), full_to.c_str());
+        return (result == 0) ? 0 : -errno;
     }
 
     int link(std::string const & old_path, std::string const & new_path) override
     {
-        return -ENOENT;
+        auto const from = get_full_path(old_path);
+        auto const to = get_full_path(new_path);
+
+        int const result = ::link(from.c_str(), to.c_str());
+        return (result == 0) ? 0 : -errno;
     }
 
     int rename(std::string const & old_path, std::string const & new_path, int flags) override
     {
-        return -ENOENT;
+        auto const full_old = get_full_path(old_path);
+        auto const full_new = get_full_path(new_path);
+
+        int const result = ::renameat2(-1, full_old.c_str(), -1, full_new.c_str(), flags);
+        return (result == 0) ? 0 : -errno;
     }
 
     int chmod(std::string const & path, mode_t mode) override
     {
-        return -ENOENT;
+        auto const full_path = get_full_path(path);
+
+        int const result = ::chmod(full_path.c_str(), mode);
+        return (result == 0) ? 0 : -errno;
     }
 
     int chown(std::string const & path, uid_t uid, gid_t gid) override
     {
-        return -ENOENT;
+        auto const full_path = get_full_path(path);
+
+        int const result = ::chown(full_path.c_str(), uid, gid);
+        return (result == 0) ? 0 : -errno;
     }
 
     int truncate(std::string const & path, uint64_t size, uint64_t handle) override
     {
-        return -ENOENT;
+        auto const full_path = get_full_path(path);
+
+        int result = 0;
+        if (handle == webfuse::invalid_handle)
+        {
+            result = ::truncate(full_path.c_str(), size);
+        }
+        else
+        {
+            result = ::ftruncate(static_cast<int>(handle), size);
+        }
+
+        return (result == 0) ? 0 : -errno;
     }
 
     int fsync(std::string const & path, bool is_datasync, uint64_t handle) override
     {
-        return -ENOENT;
+        int result = 0;
+        if (handle != webfuse::invalid_handle)
+        {
+            if (!is_datasync)
+            {
+                result = ::fsync(static_cast<int>(handle));
+            }
+            else
+            {
+                result = ::fdatasync(static_cast<int>(handle));
+            }
+        }
+        // we do not sync files, which are not open
+
+        return (result == 0) ? 0 : -errno;
     }
 
     int utimens(std::string const &path, struct timespec const tv[2], uint64_t handle) override
     {
-        return -ENOENT;
+        int result = 0;
+        if (handle == webfuse::invalid_handle)
+        {
+            auto const full_path = get_full_path(path);
+            result = ::utimensat(-1, full_path.c_str(), tv, 0);
+        }
+        else
+        {
+            result = ::futimens(static_cast<int>(handle), tv);
+        }
+
+        return (result == 0) ? 0 : -errno;
     }
 
     int open(std::string const & path, int flags, uint64_t & handle) override
     {
-        return -ENOENT;
+        auto const full_path = get_full_path(path);
+        int const fd = ::open(full_path.c_str(), flags);
+        if (0 <= fd)
+        {
+            handle = static_cast<int>(fd);
+        }
+        
+        return (0 <= fd) ? 0 : -errno;
     }
 
     int mknod(std::string const & path, mode_t mode, dev_t rdev) override
     {
-        return -ENOENT;
+        auto const full_path = get_full_path(path);
+        int const result = ::mknod(full_path.c_str(), mode, rdev);
+
+        return (result == 0) ? 0 : -errno;
     }
 
     int create(std::string const & path, mode_t mode, uint64_t & handle) override
     {
-        return -ENOENT;
+        auto const full_path = get_full_path(path);
+        int const fd = ::creat(full_path.c_str(), mode);
+        if (0 <= fd)
+        {
+            handle = static_cast<int>(fd);
+        }
+        
+        return (0 <= fd) ? 0 : -errno;
     }
 
     int release(std::string const & path, uint64_t handle) override
     {
-        return -ENOENT;
+        int result = 0;
+        if (handle != webfuse::invalid_handle)
+        {
+            result = ::close(static_cast<int>(handle));
+        }
+
+        return (result == 0) ? 0 : -errno;
     }
 
     int unlink(std::string const & path) override
     {
-        return -ENOENT;
+        auto const full_path = get_full_path(path);
+        int const result = ::unlink(full_path.c_str());
+
+        return (result == 0) ? 0 : -errno;
     }
 
     int read(std::string const & path, char * buffer, size_t buffer_size, uint64_t offset, uint64_t handle) override
     {
-        return -ENOENT;
+        int result = -1;
+        if (handle != webfuse::invalid_handle)
+        {
+            auto const full_path = get_full_path(path);
+            int fd = ::open(full_path.c_str(), O_RDONLY);
+            if (0 <= fd)
+            {
+                result = ::pread(fd, buffer, buffer_size, offset);
+                ::close(fd);
+            }
+        }
+        else
+        {
+            result = ::pread(static_cast<int>(handle), buffer, buffer_size, offset);
+        }
+
+        return (result >= 0) ? result : -errno;
     }
 
     int write(std::string const & path, char const * buffer, size_t buffer_size, uint64_t offset, uint64_t handle) override
     {
-        return -ENOENT;
+        int result = -1;
+        if (handle == webfuse::invalid_handle)
+        {
+            auto const full_path = get_full_path(path);
+            int fd = ::open(full_path.c_str(), O_WRONLY);
+            if (0 <= fd)
+            {
+                result = ::pwrite(fd, buffer, buffer_size, offset);
+                ::close(fd);
+            }
+        }
+        else
+        {
+            result = ::pwrite(static_cast<int>(handle), buffer, buffer_size, offset);
+
+        }
+
+        return (result >= 0) ? result : -errno;
     }
 
     int mkdir(std::string const & path, mode_t mode) override
     {
-        return -ENOENT;
+        auto const full_path = get_full_path(path);
+        int const result = ::mkdir(full_path.c_str(), mode);
+
+        return (result == 0) ? 0 : -errno;
     }
 
     int readdir(std::string const & path, std::vector<std::string> & entries) override
     {
         auto const full_path = get_full_path(path);
-        std::cout << "readdir: " << full_path << std::endl;
 
         int result = 0;
         DIR * directory = opendir(full_path.c_str());
@@ -260,12 +398,18 @@ public:
 
     int rmdir(std::string const & path) override
     {
-        return -ENOENT;
+        auto const full_path = get_full_path(path);
+        int const result = ::rmdir(full_path.c_str());
+
+        return (result == 0) ? 0 : -errno;
     }
 
     int statfs(std::string const & path, struct statvfs * statistics) override
     {
-        return -ENOENT;
+        auto const full_path = get_full_path(path);
+        int const result = ::statvfs(full_path.c_str(), statistics);
+
+        return (result == 0) ? 0 : -errno;
     }
 
 
@@ -289,6 +433,7 @@ int main(int argc, char* argv[])
     switch (ctx.cmd)
     {
         case command::run:
+            try
             {
                 signal(SIGINT, &on_signal);
                 signal(SIGTERM, &on_signal);
@@ -307,6 +452,16 @@ int main(int argc, char* argv[])
                     provider.service();
                 }
             }
+            catch (std::exception const & ex)
+            {
+                std::cerr << "error: " << ex.what() << std::endl;
+                ctx.exit_code = EXIT_FAILURE;
+            }
+            catch (...)
+            {
+                std::cerr << "error: unspecified error" << std::endl;
+                ctx.exit_code = EXIT_FAILURE;
+            }
             break;
         case command::show_version:
             print_version();

src/webfuse/filesystem/filesystem_i.hpp

@@ -13,6 +13,8 @@
 namespace webfuse
 {
 
+constexpr uint64_t const invalid_handle = static_cast<uint64_t>(-1);
+
 class filesystem_i
 {
 public: