83 lines
1.7 KiB
C++
83 lines
1.7 KiB
C++
/*
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* \brief Symlink file-system node
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* \author Norman Feske
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* \date 2012-04-11
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*/
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/*
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* Copyright (C) 2012-2017 Genode Labs GmbH
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*
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* This file is part of the Genode OS framework, which is distributed
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* under the terms of the GNU Affero General Public License version 3.
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*/
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#ifndef _INCLUDE__RAM_FS__SYMLINK_H_
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#define _INCLUDE__RAM_FS__SYMLINK_H_
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/* local includes */
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#include "node.h"
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namespace Ram_fs { class Symlink; }
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class Ram_fs::Symlink : public Node
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{
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private:
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char _link_to[File_system::MAX_PATH_LEN];
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size_t _len;
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public:
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Symlink(char const *name): _len(0) { Node::name(name); }
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size_t read(char *dst, size_t len, seek_off_t seek_offset) override
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{
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size_t count = min(len, _len-seek_offset);
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Genode::memcpy(dst, _link_to+seek_offset, count);
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return count;
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}
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size_t write(char const *src, size_t len, seek_off_t seek_offset) override
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{
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size_t const consumed_len = len;
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/* Ideal symlink operations are atomic. */
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if (seek_offset) return 0;
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for (size_t i = 0; i < len; ++i) {
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if (src[i] == '\0') {
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len = i;
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break;
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}
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}
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/*
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* if the target is too long return a
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* short result to indicate the error
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*/
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if (len > sizeof(_link_to))
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return len >> 1;
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Genode::memcpy(_link_to, src, len);
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_len = len;
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return consumed_len;
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}
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Status status() override
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{
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return {
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.size = _len,
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.type = File_system::Node_type::SYMLINK,
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.rwx = { .readable = true,
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.writeable = true,
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.executable = true },
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.inode = inode(),
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.modification_time = modification_time()
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};
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}
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};
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#endif /* _INCLUDE__RAM_FS__SYMLINK_H_ */
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