#include "config.h" #include <cerrno> #include <algorithm> #include <vector> #define _XOPEN_SOURCE 600 #include <sys/types.h> #include <sys/stat.h> #include <unistd.h> #include <dirent.h> #include <fcntl.h> #include "archive.hh" #include "util.hh" namespace nix { static string archiveVersion1 = "nix-archive-1"; PathFilter defaultPathFilter; static void dump(const string & path, Sink & sink, PathFilter & filter); static void dumpEntries(const Path & path, Sink & sink, PathFilter & filter) { Strings names = readDirectory(path); vector<string> names2(names.begin(), names.end()); sort(names2.begin(), names2.end()); for (vector<string>::iterator i = names2.begin(); i != names2.end(); ++i) { Path entry = path + "/" + *i; if (filter(entry)) { writeString("entry", sink); writeString("(", sink); writeString("name", sink); writeString(*i, sink); writeString("node", sink); dump(entry, sink, filter); writeString(")", sink); } } } static void dumpContents(const Path & path, size_t size, Sink & sink) { writeString("contents", sink); writeLongLong(size, sink); AutoCloseFD fd = open(path.c_str(), O_RDONLY); if (fd == -1) throw SysError(format("opening file `%1%'") % path); unsigned char buf[65536]; size_t left = size; while (left > 0) { size_t n = left > sizeof(buf) ? sizeof(buf) : left; readFull(fd, buf, n); left -= n; sink(buf, n); } writePadding(size, sink); } static void dump(const Path & path, Sink & sink, PathFilter & filter) { struct stat st; if (lstat(path.c_str(), &st)) throw SysError(format("getting attributes of path `%1%'") % path); writeString("(", sink); if (S_ISREG(st.st_mode)) { writeString("type", sink); writeString("regular", sink); if (st.st_mode & S_IXUSR) { writeString("executable", sink); writeString("", sink); } dumpContents(path, (size_t) st.st_size, sink); } else if (S_ISDIR(st.st_mode)) { writeString("type", sink); writeString("directory", sink); dumpEntries(path, sink, filter); } else if (S_ISLNK(st.st_mode)) { writeString("type", sink); writeString("symlink", sink); writeString("target", sink); writeString(readLink(path), sink); } else throw Error(format("file `%1%' has an unknown type") % path); writeString(")", sink); } void dumpPath(const Path & path, Sink & sink, PathFilter & filter) { writeString(archiveVersion1, sink); dump(path, sink, filter); } static SerialisationError badArchive(string s) { return SerialisationError("bad archive: " + s); } static void skipGeneric(Source & source) { if (readString(source) == "(") { while (readString(source) != ")") skipGeneric(source); } } static void parse(ParseSink & sink, Source & source, const Path & path); static void parseEntry(ParseSink & sink, Source & source, const Path & path) { string s, name; s = readString(source); if (s != "(") throw badArchive("expected open tag"); while (1) { checkInterrupt(); s = readString(source); if (s == ")") { break; } else if (s == "name") { name = readString(source); } else if (s == "node") { if (s == "") throw badArchive("entry name missing"); parse(sink, source, path + "/" + name); } else { throw badArchive("unknown field " + s); skipGeneric(source); } } } static void parseContents(ParseSink & sink, Source & source, const Path & path) { unsigned long long size = readLongLong(source); sink.preallocateContents(size); unsigned long long left = size; unsigned char buf[65536]; while (left) { checkInterrupt(); unsigned int n = sizeof(buf); if ((unsigned long long) n > left) n = left; source(buf, n); sink.receiveContents(buf, n); left -= n; } sink.finalizeContents(size); readPadding(size, source); } static void parse(ParseSink & sink, Source & source, const Path & path) { string s; s = readString(source); if (s != "(") throw badArchive("expected open tag"); enum { tpUnknown, tpRegular, tpDirectory, tpSymlink } type = tpUnknown; while (1) { checkInterrupt(); s = readString(source); if (s == ")") { break; } else if (s == "type") { if (type != tpUnknown) throw badArchive("multiple type fields"); string t = readString(source); if (t == "regular") { type = tpRegular; sink.createRegularFile(path); } else if (t == "directory") { sink.createDirectory(path); type = tpDirectory; } else if (t == "symlink") { type = tpSymlink; } else throw badArchive("unknown file type " + t); } else if (s == "contents" && type == tpRegular) { parseContents(sink, source, path); } else if (s == "executable" && type == tpRegular) { readString(source); sink.isExecutable(); } else if (s == "entry" && type == tpDirectory) { parseEntry(sink, source, path); } else if (s == "target" && type == tpSymlink) { string target = readString(source); sink.createSymlink(path, target); } else { throw badArchive("unknown field " + s); skipGeneric(source); } } } void parseDump(ParseSink & sink, Source & source) { string version; try { version = readString(source); } catch (SerialisationError & e) { /* This generally means the integer at the start couldn't be decoded. Ignore and throw the exception below. */ } if (version != archiveVersion1) throw badArchive("input doesn't look like a Nix archive"); parse(sink, source, ""); } struct RestoreSink : ParseSink { Path dstPath; AutoCloseFD fd; void createDirectory(const Path & path) { Path p = dstPath + path; if (mkdir(p.c_str(), 0777) == -1) throw SysError(format("creating directory `%1%'") % p); }; void createRegularFile(const Path & path) { Path p = dstPath + path; fd = open(p.c_str(), O_CREAT | O_EXCL | O_WRONLY, 0666); if (fd == -1) throw SysError(format("creating file `%1%'") % p); } void isExecutable() { struct stat st; if (fstat(fd, &st) == -1) throw SysError("fstat"); if (fchmod(fd, st.st_mode | (S_IXUSR | S_IXGRP | S_IXOTH)) == -1) throw SysError("fchmod"); } void preallocateContents(unsigned long long len) { #if HAVE_POSIX_FALLOCATE if (len) { errno = posix_fallocate(fd, 0, len); /* Note that EINVAL may indicate that the underlying filesystem doesn't support preallocation (e.g. on OpenSolaris). Since preallocation is just an optimisation, ignore it. */ if (errno && errno != EINVAL) throw SysError(format("preallocating file of %1% bytes") % len); } #endif } void receiveContents(unsigned char * data, unsigned int len) { writeFull(fd, data, len); } void finalizeContents(unsigned long long size) { errno = ftruncate(fd, size); if (errno) throw SysError(format("truncating file to its allocated length of %1% bytes") % size); } void createSymlink(const Path & path, const string & target) { Path p = dstPath + path; if (symlink(target.c_str(), p.c_str()) == -1) throw SysError(format("creating symlink `%1%'") % p); } }; void restorePath(const Path & path, Source & source) { RestoreSink sink; sink.dstPath = path; parseDump(sink, source); } }