// Includes /*{{{*/ #include <apt-pkg/fileutl.h> #include <apt-pkg/mmap.h> #include <apt-pkg/error.h> #include <apt-pkg/acquire-method.h> #include <apt-pkg/strutl.h> #include <apt-pkg/hashes.h> #include <sys/stat.h> #include <sys/uio.h> #include <unistd.h> #include <utime.h> #include <stdio.h> #include <errno.h> #include <apti18n.h> /*}}}*/ /** \brief RredMethod - ed-style incremential patch method {{{ * * This method implements a patch functionality similar to "patch --ed" that is * used by the "tiffany" incremental packages download stuff. It differs from * "ed" insofar that it is way more restricted (and therefore secure). * The currently supported ed commands are "<em>c</em>hange", "<em>a</em>dd" and * "<em>d</em>elete" (diff doesn't output any other). * Additionally the records must be reverse sorted by line number and * may not overlap (diff *seems* to produce this kind of output). * */ class RredMethod : public pkgAcqMethod { bool Debug; // the size of this doesn't really matter (except for performance) const static int BUF_SIZE = 1024; // the supported ed commands enum Mode {MODE_CHANGED='c', MODE_DELETED='d', MODE_ADDED='a'}; // return values enum State {ED_OK, ED_ORDERING, ED_PARSER, ED_FAILURE, MMAP_FAILED}; State applyFile(FILE *ed_cmds, FILE *in_file, FILE *out_file, unsigned long &line, char *buffer, Hashes *hash) const; void ignoreLineInFile(FILE *fin, char *buffer) const; void copyLinesFromFileToFile(FILE *fin, FILE *fout, unsigned int lines, Hashes *hash, char *buffer) const; State patchFile(FileFd &Patch, FileFd &From, FileFd &out_file, Hashes *hash) const; State patchMMap(FileFd &Patch, FileFd &From, FileFd &out_file, Hashes *hash) const; protected: // the methods main method virtual bool Fetch(FetchItem *Itm); public: RredMethod() : pkgAcqMethod("1.1",SingleInstance | SendConfig) {}; }; /*}}}*/ /** \brief applyFile - in reverse order with a tail recursion {{{ * * As it is expected that the commands are in reversed order in the patch file * we check in the first half if the command is valid, but doesn't execute it * and move a step deeper. After reaching the end of the file we apply the * patches in the correct order: last found command first. * * \param ed_cmds patch file to apply * \param in_file base file we want to patch * \param out_file file to write the patched result to * \param line of command operation * \param buffer internal used read/write buffer * \param hash the created file for correctness * \return the success State of the ed command executor */ RredMethod::State RredMethod::applyFile(FILE *ed_cmds, FILE *in_file, FILE *out_file, unsigned long &line, char *buffer, Hashes *hash) const { // get the current command and parse it if (fgets(buffer, BUF_SIZE, ed_cmds) == NULL) { if (Debug == true) std::clog << "rred: encounter end of file - we can start patching now." << std::endl; line = 0; return ED_OK; } // parse in the effected linenumbers char* idx; errno=0; unsigned long const startline = strtol(buffer, &idx, 10); if (errno == ERANGE || errno == EINVAL) { _error->Errno("rred", "startline is an invalid number"); return ED_PARSER; } if (startline > line) { _error->Error("rred: The start line (%lu) of the next command is higher than the last line (%lu). This is not allowed.", startline, line); return ED_ORDERING; } unsigned long stopline; if (*idx == ',') { idx++; errno=0; stopline = strtol(idx, &idx, 10); if (errno == ERANGE || errno == EINVAL) { _error->Errno("rred", "stopline is an invalid number"); return ED_PARSER; } } else { stopline = startline; } line = startline; // which command to execute on this line(s)? switch (*idx) { case MODE_CHANGED: if (Debug == true) std::clog << "Change from line " << startline << " to " << stopline << std::endl; break; case MODE_ADDED: if (Debug == true) std::clog << "Insert after line " << startline << std::endl; break; case MODE_DELETED: if (Debug == true) std::clog << "Delete from line " << startline << " to " << stopline << std::endl; break; default: _error->Error("rred: Unknown ed command '%c'. Abort.", *idx); return ED_PARSER; } unsigned char mode = *idx; // save the current position unsigned const long pos = ftell(ed_cmds); // if this is add or change then go to the next full stop unsigned int data_length = 0; if (mode == MODE_CHANGED || mode == MODE_ADDED) { do { ignoreLineInFile(ed_cmds, buffer); data_length++; } while (strncmp(buffer, ".", 1) != 0); data_length--; // the dot should not be copied } // do the recursive call - the last command is the one we need to execute at first const State child = applyFile(ed_cmds, in_file, out_file, line, buffer, hash); if (child != ED_OK) { return child; } // change and delete are working on "line" - add is done after "line" if (mode != MODE_ADDED) line++; // first wind to the current position and copy over all unchanged lines if (line < startline) { copyLinesFromFileToFile(in_file, out_file, (startline - line), hash, buffer); line = startline; } if (mode != MODE_ADDED) line--; // include data from ed script if (mode == MODE_CHANGED || mode == MODE_ADDED) { fseek(ed_cmds, pos, SEEK_SET); copyLinesFromFileToFile(ed_cmds, out_file, data_length, hash, buffer); } // ignore the corresponding number of lines from input if (mode == MODE_CHANGED || mode == MODE_DELETED) { while (line < stopline) { ignoreLineInFile(in_file, buffer); line++; } } return ED_OK; } /*}}}*/ void RredMethod::copyLinesFromFileToFile(FILE *fin, FILE *fout, unsigned int lines,/*{{{*/ Hashes *hash, char *buffer) const { while (0 < lines--) { do { fgets(buffer, BUF_SIZE, fin); size_t const written = fwrite(buffer, 1, strlen(buffer), fout); hash->Add((unsigned char*)buffer, written); } while (strlen(buffer) == (BUF_SIZE - 1) && buffer[BUF_SIZE - 2] != '\n'); } } /*}}}*/ void RredMethod::ignoreLineInFile(FILE *fin, char *buffer) const { /*{{{*/ fgets(buffer, BUF_SIZE, fin); while (strlen(buffer) == (BUF_SIZE - 1) && buffer[BUF_SIZE - 2] != '\n') { fgets(buffer, BUF_SIZE, fin); buffer[0] = ' '; } } /*}}}*/ RredMethod::State RredMethod::patchFile(FileFd &Patch, FileFd &From, /*{{{*/ FileFd &out_file, Hashes *hash) const { char buffer[BUF_SIZE]; FILE* fFrom = fdopen(From.Fd(), "r"); FILE* fPatch = fdopen(Patch.Fd(), "r"); FILE* fTo = fdopen(out_file.Fd(), "w"); /* we do a tail recursion to read the commands in the right order */ unsigned long line = -1; // assign highest possible value State const result = applyFile(fPatch, fFrom, fTo, line, buffer, hash); /* read the rest from infile */ if (result == ED_OK) { while (fgets(buffer, BUF_SIZE, fFrom) != NULL) { size_t const written = fwrite(buffer, 1, strlen(buffer), fTo); hash->Add((unsigned char*)buffer, written); } fflush(fTo); } return result; } /*}}}*/ struct EdCommand { /*{{{*/ size_t data_start; size_t data_end; size_t data_lines; size_t first_line; size_t last_line; char type; }; #define IOV_COUNT 1024 /* Don't really want IOV_MAX since it can be arbitrarily large */ /*}}}*/ RredMethod::State RredMethod::patchMMap(FileFd &Patch, FileFd &From, /*{{{*/ FileFd &out_file, Hashes *hash) const { #ifdef _POSIX_MAPPED_FILES MMap ed_cmds(Patch, MMap::ReadOnly); MMap in_file(From, MMap::ReadOnly); if (ed_cmds.Size() == 0 || in_file.Size() == 0) return MMAP_FAILED; EdCommand* commands = 0; size_t command_count = 0; size_t command_alloc = 0; const char* begin = (char*) ed_cmds.Data(); const char* end = begin; const char* ed_end = (char*) ed_cmds.Data() + ed_cmds.Size(); const char* input = (char*) in_file.Data(); const char* input_end = (char*) in_file.Data() + in_file.Size(); size_t i; /* 1. Parse entire script. It is executed in reverse order, so we cather it * in the `commands' buffer first */ for(;;) { EdCommand cmd; cmd.data_start = 0; cmd.data_end = 0; while(begin != ed_end && *begin == '\n') ++begin; while(end != ed_end && *end != '\n') ++end; if(end == ed_end && begin == end) break; /* Determine command range */ const char* tmp = begin; for(;;) { /* atoll is safe despite lacking NUL-termination; we know there's an * alphabetic character at end[-1] */ if(tmp == end) { cmd.first_line = atol(begin); cmd.last_line = cmd.first_line; break; } if(*tmp == ',') { cmd.first_line = atol(begin); cmd.last_line = atol(tmp + 1); break; } ++tmp; } // which command to execute on this line(s)? switch (end[-1]) { case MODE_CHANGED: if (Debug == true) std::clog << "Change from line " << cmd.first_line << " to " << cmd.last_line << std::endl; break; case MODE_ADDED: if (Debug == true) std::clog << "Insert after line " << cmd.first_line << std::endl; break; case MODE_DELETED: if (Debug == true) std::clog << "Delete from line " << cmd.first_line << " to " << cmd.last_line << std::endl; break; default: _error->Error("rred: Unknown ed command '%c'. Abort.", end[-1]); free(commands); return ED_PARSER; } cmd.type = end[-1]; /* Determine the size of the inserted text, so we don't have to scan this * text again later. */ begin = end + 1; end = begin; cmd.data_lines = 0; if(cmd.type == MODE_ADDED || cmd.type == MODE_CHANGED) { cmd.data_start = begin - (char*) ed_cmds.Data(); while(end != ed_end) { if(*end == '\n') { if(end[-1] == '.' && end[-2] == '\n') break; ++cmd.data_lines; } ++end; } cmd.data_end = end - (char*) ed_cmds.Data() - 1; begin = end + 1; end = begin; } if(command_count == command_alloc) { command_alloc = (command_alloc + 64) * 3 / 2; commands = (EdCommand*) realloc(commands, command_alloc * sizeof(EdCommand)); } commands[command_count++] = cmd; } struct iovec* iov = new struct iovec[IOV_COUNT]; size_t iov_size = 0; size_t amount, remaining; size_t line = 1; EdCommand* cmd; /* 2. Execute script. We gather writes in a `struct iov' array, and flush * using writev to minimize the number of system calls. Data is read * directly from the memory mappings of the input file and the script. */ for(i = command_count; i-- > 0; ) { cmd = &commands[i]; if(cmd->type == MODE_ADDED) amount = cmd->first_line + 1; else amount = cmd->first_line; if(line < amount) { begin = input; while(line != amount) { input = (const char*) memchr(input, '\n', input_end - input); if(!input) break; ++line; ++input; } iov[iov_size].iov_base = (void*) begin; iov[iov_size].iov_len = input - begin; hash->Add((const unsigned char*) begin, input - begin); if(++iov_size == IOV_COUNT) { writev(out_file.Fd(), iov, IOV_COUNT); iov_size = 0; } } if(cmd->type == MODE_DELETED || cmd->type == MODE_CHANGED) { remaining = (cmd->last_line - cmd->first_line) + 1; line += remaining; while(remaining) { input = (const char*) memchr(input, '\n', input_end - input); if(!input) break; --remaining; ++input; } } if(cmd->type == MODE_CHANGED || cmd->type == MODE_ADDED) { if(cmd->data_end != cmd->data_start) { iov[iov_size].iov_base = (void*) ((char*)ed_cmds.Data() + cmd->data_start); iov[iov_size].iov_len = cmd->data_end - cmd->data_start; hash->Add((const unsigned char*) ((char*)ed_cmds.Data() + cmd->data_start), iov[iov_size].iov_len); if(++iov_size == IOV_COUNT) { writev(out_file.Fd(), iov, IOV_COUNT); iov_size = 0; } } } } if(input != input_end) { iov[iov_size].iov_base = (void*) input; iov[iov_size].iov_len = input_end - input; hash->Add((const unsigned char*) input, input_end - input); ++iov_size; } if(iov_size) { writev(out_file.Fd(), iov, iov_size); iov_size = 0; } for(i = 0; i < iov_size; i += IOV_COUNT) { if(iov_size - i < IOV_COUNT) writev(out_file.Fd(), iov + i, iov_size - i); else writev(out_file.Fd(), iov + i, IOV_COUNT); } delete [] iov; free(commands); return ED_OK; #else return MMAP_FAILED; #endif } /*}}}*/ bool RredMethod::Fetch(FetchItem *Itm) /*{{{*/ { Debug = _config->FindB("Debug::pkgAcquire::RRed", false); URI Get = Itm->Uri; string Path = Get.Host + Get.Path; // To account for relative paths FetchResult Res; Res.Filename = Itm->DestFile; if (Itm->Uri.empty() == true) { Path = Itm->DestFile; Itm->DestFile.append(".result"); } else URIStart(Res); if (Debug == true) std::clog << "Patching " << Path << " with " << Path << ".ed and putting result into " << Itm->DestFile << std::endl; // Open the source and destination files (the d'tor of FileFd will do // the cleanup/closing of the fds) FileFd From(Path,FileFd::ReadOnly); FileFd Patch(Path+".ed",FileFd::ReadOnly); FileFd To(Itm->DestFile,FileFd::WriteEmpty); To.EraseOnFailure(); if (_error->PendingError() == true) return false; Hashes Hash; // now do the actual patching State const result = patchMMap(Patch, From, To, &Hash); if (result == MMAP_FAILED) { // retry with patchFile lseek(Patch.Fd(), 0, SEEK_SET); lseek(From.Fd(), 0, SEEK_SET); To.Open(Itm->DestFile,FileFd::WriteEmpty); if (_error->PendingError() == true) return false; if (patchFile(Patch, From, To, &Hash) != ED_OK) { return _error->WarningE("rred", _("Could not patch %s with mmap and with file operation usage - the patch seems to be corrupt."), Path.c_str()); } else if (Debug == true) { std::clog << "rred: finished file patching of " << Path << " after mmap failed." << std::endl; } } else if (result != ED_OK) { return _error->Errno("rred", _("Could not patch %s with mmap (but no mmap specific fail) - the patch seems to be corrupt."), Path.c_str()); } else if (Debug == true) { std::clog << "rred: finished mmap patching of " << Path << std::endl; } // write out the result From.Close(); Patch.Close(); To.Close(); // Transfer the modification times struct stat Buf; if (stat(Path.c_str(),&Buf) != 0) return _error->Errno("stat",_("Failed to stat")); struct utimbuf TimeBuf; TimeBuf.actime = Buf.st_atime; TimeBuf.modtime = Buf.st_mtime; if (utime(Itm->DestFile.c_str(),&TimeBuf) != 0) return _error->Errno("utime",_("Failed to set modification time")); if (stat(Itm->DestFile.c_str(),&Buf) != 0) return _error->Errno("stat",_("Failed to stat")); // return done Res.LastModified = Buf.st_mtime; Res.Size = Buf.st_size; Res.TakeHashes(Hash); URIDone(Res); return true; } /*}}}*/ /** \brief Wrapper class for testing rred */ /*{{{*/ class TestRredMethod : public RredMethod { public: /** \brief Run rred in debug test mode * * This method can be used to run the rred method outside * of the "normal" acquire environment for easier testing. * * \param base basename of all files involved in this rred test */ bool Run(char const *base) { _config->CndSet("Debug::pkgAcquire::RRed", "true"); FetchItem *test = new FetchItem; test->DestFile = base; return Fetch(test); } }; /*}}}*/ /** \brief Starter for the rred method (or its test method) {{{ * * Used without parameters is the normal behavior for methods for * the APT acquire system. While this works great for the acquire system * it is very hard to test the method and therefore the method also * accepts one parameter which will switch it directly to debug test mode: * The test mode expects that if "Testfile" is given as parameter * the file "Testfile" should be ed-style patched with "Testfile.ed" * and will write the result to "Testfile.result". */ int main(int argc, char *argv[]) { if (argc <= 1) { RredMethod Mth; return Mth.Run(); } else { TestRredMethod Mth; bool result = Mth.Run(argv[1]); _error->DumpErrors(); return result; } } /*}}}*/