diff options
Diffstat (limited to 'apt-pkg/contrib/strutl.cc')
| -rw-r--r-- | apt-pkg/contrib/strutl.cc | 150 |
1 files changed, 91 insertions, 59 deletions
diff --git a/apt-pkg/contrib/strutl.cc b/apt-pkg/contrib/strutl.cc index 87f57a30e..ebf9c9ea6 100644 --- a/apt-pkg/contrib/strutl.cc +++ b/apt-pkg/contrib/strutl.cc @@ -74,6 +74,13 @@ bool Endswith(const std::string &s, const std::string &end) return (s.substr(s.size() - end.size(), s.size()) == end); } +bool Startswith(const std::string &s, const std::string &start) +{ + if (start.size() > s.size()) + return false; + return (s.substr(0, start.size()) == start); +} + } } /*}}}*/ @@ -772,86 +779,94 @@ string TimeRFC1123(time_t Date) In particular: this reads blocks from the input until it believes that it's run out of input text. Each block is terminated by a - double newline ('\n' followed by '\n'). As noted below, there is a - bug in this code: it assumes that all the blocks have been read if - it doesn't see additional text in the buffer after the last one is - parsed, which will cause it to lose blocks if the last block - coincides with the end of the buffer. + double newline ('\n' followed by '\n'). */ bool ReadMessages(int Fd, vector<string> &List) { char Buffer[64000]; - char *End = Buffer; // Represents any left-over from the previous iteration of the // parse loop. (i.e., if a message is split across the end // of the buffer, it goes here) string PartialMessage; - - while (1) - { - int Res = read(Fd,End,sizeof(Buffer) - (End-Buffer)); + + do { + int const Res = read(Fd, Buffer, sizeof(Buffer)); if (Res < 0 && errno == EINTR) continue; - - // Process is dead, this is kind of bad.. + + // process we read from has died if (Res == 0) return false; - + // No data - if (Res < 0 && errno == EAGAIN) + if (Res < 0 && (errno == EAGAIN || errno == EWOULDBLOCK)) return true; if (Res < 0) return false; - - End += Res; - - // Look for the end of the message - for (char *I = Buffer; I + 1 < End; I++) + + // extract the message(s) from the buffer + char const *Start = Buffer; + char const * const End = Buffer + Res; + + char const * NL = (char const *) memchr(Start, '\n', End - Start); + if (NL == NULL) { - if (I[1] != '\n' || - (I[0] != '\n' && strncmp(I, "\r\n\r\n", 4) != 0)) - continue; - - // Pull the message out - string Message(Buffer,I-Buffer); - PartialMessage += Message; - - // Fix up the buffer - for (; I < End && (*I == '\n' || *I == '\r'); ++I); - End -= I-Buffer; - memmove(Buffer,I,End-Buffer); - I = Buffer; - - List.push_back(PartialMessage); - PartialMessage.clear(); + // end of buffer: store what we have so far and read new data in + PartialMessage.append(Start, End - Start); + Start = End; } - if (End != Buffer) - { - // If there's text left in the buffer, store it - // in PartialMessage and throw the rest of the buffer - // away. This allows us to handle messages that - // are longer than the static buffer size. - PartialMessage += string(Buffer, End); - End = Buffer; - } else - { - // BUG ALERT: if a message block happens to end at a - // multiple of 64000 characters, this will cause it to - // terminate early, leading to a badly formed block and - // probably crashing the method. However, this is the only - // way we have to find the end of the message block. I have - // an idea of how to fix this, but it will require changes - // to the protocol (essentially to mark the beginning and - // end of the block). - // - // -- dburrows 2008-04-02 - return true; - } + ++NL; + + if (PartialMessage.empty() == false && Start < End) + { + // if we start with a new line, see if the partial message we have ended with one + // so that we properly detect records ending between two read() runs + // cases are: \n|\n , \r\n|\r\n and \r\n\r|\n + // the case \r|\n\r\n is handled by the usual double-newline handling + if ((NL - Start) == 1 || ((NL - Start) == 2 && *Start == '\r')) + { + if (APT::String::Endswith(PartialMessage, "\n") || APT::String::Endswith(PartialMessage, "\r\n\r")) + { + PartialMessage.erase(PartialMessage.find_last_not_of("\r\n") + 1); + List.push_back(PartialMessage); + PartialMessage.clear(); + while (NL < End && (*NL == '\n' || *NL == '\r')) ++NL; + Start = NL; + } + } + } + + while (Start < End) { + char const * NL2 = (char const *) memchr(NL, '\n', End - NL); + if (NL2 == NULL) + { + // end of buffer: store what we have so far and read new data in + PartialMessage.append(Start, End - Start); + break; + } + ++NL2; + + // did we find a double newline? + if ((NL2 - NL) == 1 || ((NL2 - NL) == 2 && *NL == '\r')) + { + PartialMessage.append(Start, NL2 - Start); + PartialMessage.erase(PartialMessage.find_last_not_of("\r\n") + 1); + List.push_back(PartialMessage); + PartialMessage.clear(); + while (NL2 < End && (*NL2 == '\n' || *NL2 == '\r')) ++NL2; + Start = NL2; + } + NL = NL2; + } + + // we have read at least one complete message and nothing left + if (PartialMessage.empty() == true) + return true; if (WaitFd(Fd) == false) return false; - } + } while (true); } /*}}}*/ // MonthConv - Converts a month string into a number /*{{{*/ @@ -1061,7 +1076,7 @@ bool StrToNum(const char *Str,unsigned long long &Res,unsigned Len,unsigned Base // --------------------------------------------------------------------- /* This is used in decoding the 256bit encoded fixed length fields in tar files */ -bool Base256ToNum(const char *Str,unsigned long &Res,unsigned int Len) +bool Base256ToNum(const char *Str,unsigned long long &Res,unsigned int Len) { if ((Str[0] & 0x80) == 0) return false; @@ -1074,6 +1089,23 @@ bool Base256ToNum(const char *Str,unsigned long &Res,unsigned int Len) } } /*}}}*/ +// Base256ToNum - Convert a fixed length binary to a number /*{{{*/ +// --------------------------------------------------------------------- +/* This is used in decoding the 256bit encoded fixed length fields in + tar files */ +bool Base256ToNum(const char *Str,unsigned long &Res,unsigned int Len) +{ + unsigned long long Num; + bool rc; + + rc = Base256ToNum(Str, Num, Len); + Res = Num; + if (Res != Num) + return false; + + return rc; +} + /*}}}*/ // HexDigit - Convert a hex character into an integer /*{{{*/ // --------------------------------------------------------------------- /* Helper for Hex2Num */ |