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Diffstat (limited to 'server.cc')
| -rw-r--r-- | server.cc | 663 |
1 files changed, 663 insertions, 0 deletions
diff --git a/server.cc b/server.cc new file mode 100644 index 0000000..5a13f18 --- /dev/null +++ b/server.cc @@ -0,0 +1,663 @@ +// -*- mode: cpp; mode: fold -*- +// Description /*{{{*/ +/* ###################################################################### + + HTTP and HTTPS share a lot of common code and these classes are + exactly the dumping ground for this common code + + ##################################################################### */ + /*}}}*/ +// Include Files /*{{{*/ +#include <config.h> + +#include <apt-pkg/acquire-method.h> +#include <apt-pkg/configuration.h> +#include <apt-pkg/error.h> +#include <apt-pkg/fileutl.h> +#include <apt-pkg/strutl.h> + +#include <ctype.h> +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> +#include <sys/stat.h> +#include <sys/time.h> +#include <time.h> +#include <unistd.h> +#include <iostream> +#include <limits> +#include <map> +#include <string> +#include <vector> + +#include "server.h" + +#include <apti18n.h> + /*}}}*/ +using namespace std; + +string ServerMethod::FailFile; +int ServerMethod::FailFd = -1; +time_t ServerMethod::FailTime = 0; + +// ServerState::RunHeaders - Get the headers before the data /*{{{*/ +// --------------------------------------------------------------------- +/* Returns 0 if things are OK, 1 if an IO error occurred and 2 if a header + parse error occurred */ +ServerState::RunHeadersResult ServerState::RunHeaders(FileFd * const File) +{ + State = Header; + + Owner->Status(_("Waiting for headers")); + + Major = 0; + Minor = 0; + Result = 0; + Size = 0; + StartPos = 0; + Encoding = Closes; + HaveContent = false; + time(&Date); + + do + { + string Data; + if (ReadHeaderLines(Data) == false) + continue; + + if (Owner->Debug == true) + clog << Data; + + for (string::const_iterator I = Data.begin(); I < Data.end(); ++I) + { + string::const_iterator J = I; + for (; J != Data.end() && *J != '\n' && *J != '\r'; ++J); + if (HeaderLine(string(I,J)) == false) + return RUN_HEADERS_PARSE_ERROR; + I = J; + } + + // 100 Continue is a Nop... + if (Result == 100) + continue; + + // Tidy up the connection persistence state. + if (Encoding == Closes && HaveContent == true) + Persistent = false; + + return RUN_HEADERS_OK; + } + while (LoadNextResponse(false, File) == true); + + return RUN_HEADERS_IO_ERROR; +} + /*}}}*/ +// ServerState::HeaderLine - Process a header line /*{{{*/ +// --------------------------------------------------------------------- +/* */ +bool ServerState::HeaderLine(string Line) +{ + if (Line.empty() == true) + return true; + + string::size_type Pos = Line.find(' '); + if (Pos == string::npos || Pos+1 > Line.length()) + { + // Blah, some servers use "connection:closes", evil. + Pos = Line.find(':'); + if (Pos == string::npos || Pos + 2 > Line.length()) + return _error->Error(_("Bad header line")); + Pos++; + } + + // Parse off any trailing spaces between the : and the next word. + string::size_type Pos2 = Pos; + while (Pos2 < Line.length() && isspace(Line[Pos2]) != 0) + Pos2++; + + string Tag = string(Line,0,Pos); + string Val = string(Line,Pos2); + + if (stringcasecmp(Tag.c_str(),Tag.c_str()+4,"HTTP") == 0) + { + // Evil servers return no version + if (Line[4] == '/') + { + int const elements = sscanf(Line.c_str(),"HTTP/%3u.%3u %3u%359[^\n]",&Major,&Minor,&Result,Code); + if (elements == 3) + { + Code[0] = '\0'; + if (Owner->Debug == true) + clog << "HTTP server doesn't give Reason-Phrase for " << Result << std::endl; + } + else if (elements != 4) + return _error->Error(_("The HTTP server sent an invalid reply header")); + } + else + { + Major = 0; + Minor = 9; + if (sscanf(Line.c_str(),"HTTP %3u%359[^\n]",&Result,Code) != 2) + return _error->Error(_("The HTTP server sent an invalid reply header")); + } + + /* Check the HTTP response header to get the default persistence + state. */ + if (Major < 1) + Persistent = false; + else + { + if (Major == 1 && Minor == 0) + Persistent = false; + else + Persistent = true; + } + + return true; + } + + if (stringcasecmp(Tag,"Content-Length:") == 0) + { + if (Encoding == Closes) + Encoding = Stream; + HaveContent = true; + + // The length is already set from the Content-Range header + if (StartPos != 0) + return true; + + Size = strtoull(Val.c_str(), NULL, 10); + if (Size >= std::numeric_limits<unsigned long long>::max()) + return _error->Errno("HeaderLine", _("The HTTP server sent an invalid Content-Length header")); + else if (Size == 0) + HaveContent = false; + return true; + } + + if (stringcasecmp(Tag,"Content-Type:") == 0) + { + HaveContent = true; + return true; + } + + if (stringcasecmp(Tag,"Content-Range:") == 0) + { + HaveContent = true; + + // ยง14.16 says 'byte-range-resp-spec' should be a '*' in case of 416 + if (Result == 416 && sscanf(Val.c_str(), "bytes */%llu",&Size) == 1) + { + StartPos = 1; // ignore Content-Length, it would override Size + HaveContent = false; + } + else if (sscanf(Val.c_str(),"bytes %llu-%*u/%llu",&StartPos,&Size) != 2) + return _error->Error(_("The HTTP server sent an invalid Content-Range header")); + if ((unsigned long long)StartPos > Size) + return _error->Error(_("This HTTP server has broken range support")); + return true; + } + + if (stringcasecmp(Tag,"Transfer-Encoding:") == 0) + { + HaveContent = true; + if (stringcasecmp(Val,"chunked") == 0) + Encoding = Chunked; + return true; + } + + if (stringcasecmp(Tag,"Connection:") == 0) + { + if (stringcasecmp(Val,"close") == 0) + Persistent = false; + if (stringcasecmp(Val,"keep-alive") == 0) + Persistent = true; + return true; + } + + if (stringcasecmp(Tag,"Last-Modified:") == 0) + { + if (RFC1123StrToTime(Val.c_str(), Date) == false) + return _error->Error(_("Unknown date format")); + return true; + } + + if (stringcasecmp(Tag,"Location:") == 0) + { + Location = Val; + return true; + } + + return true; +} + /*}}}*/ +// ServerState::ServerState - Constructor /*{{{*/ +ServerState::ServerState(URI Srv, ServerMethod *Owner) : ServerName(Srv), TimeOut(120), Owner(Owner) +{ + Reset(); +} + /*}}}*/ + +bool ServerMethod::Configuration(string Message) /*{{{*/ +{ + return pkgAcqMethod::Configuration(Message); +} + /*}}}*/ + +// ServerMethod::DealWithHeaders - Handle the retrieved header data /*{{{*/ +// --------------------------------------------------------------------- +/* We look at the header data we got back from the server and decide what + to do. Returns DealWithHeadersResult (see http.h for details). + */ +ServerMethod::DealWithHeadersResult +ServerMethod::DealWithHeaders(FetchResult &Res) +{ + // Not Modified + if (Server->Result == 304) + { + unlink(Queue->DestFile.c_str()); + Res.IMSHit = true; + Res.LastModified = Queue->LastModified; + return IMS_HIT; + } + + /* Redirect + * + * Note that it is only OK for us to treat all redirection the same + * because we *always* use GET, not other HTTP methods. There are + * three redirection codes for which it is not appropriate that we + * redirect. Pass on those codes so the error handling kicks in. + */ + if (AllowRedirect + && (Server->Result > 300 && Server->Result < 400) + && (Server->Result != 300 // Multiple Choices + && Server->Result != 304 // Not Modified + && Server->Result != 306)) // (Not part of HTTP/1.1, reserved) + { + if (Server->Location.empty() == true); + else if (Server->Location[0] == '/' && Queue->Uri.empty() == false) + { + URI Uri = Queue->Uri; + if (Uri.Host.empty() == false) + NextURI = URI::SiteOnly(Uri); + else + NextURI.clear(); + NextURI.append(DeQuoteString(Server->Location)); + return TRY_AGAIN_OR_REDIRECT; + } + else + { + NextURI = DeQuoteString(Server->Location); + URI tmpURI = NextURI; + URI Uri = Queue->Uri; + // same protocol redirects are okay + if (tmpURI.Access == Uri.Access) + return TRY_AGAIN_OR_REDIRECT; + // as well as http to https + else if (Uri.Access == "http" && tmpURI.Access == "https") + return TRY_AGAIN_OR_REDIRECT; + } + /* else pass through for error message */ + } + // retry after an invalid range response without partial data + else if (Server->Result == 416) + { + struct stat SBuf; + if (stat(Queue->DestFile.c_str(),&SBuf) >= 0 && SBuf.st_size > 0) + { + if ((unsigned long long)SBuf.st_size == Server->Size) + { + // the file is completely downloaded, but was not moved + Server->StartPos = Server->Size; + Server->Result = 200; + Server->HaveContent = false; + } + else if (unlink(Queue->DestFile.c_str()) == 0) + { + NextURI = Queue->Uri; + return TRY_AGAIN_OR_REDIRECT; + } + } + } + + /* We have a reply we dont handle. This should indicate a perm server + failure */ + if (Server->Result < 200 || Server->Result >= 300) + { + char err[255]; + snprintf(err,sizeof(err)-1,"HttpError%i",Server->Result); + SetFailReason(err); + _error->Error("%u %s",Server->Result,Server->Code); + if (Server->HaveContent == true) + return ERROR_WITH_CONTENT_PAGE; + return ERROR_UNRECOVERABLE; + } + + // This is some sort of 2xx 'data follows' reply + Res.LastModified = Server->Date; + Res.Size = Server->Size; + + // Open the file + delete File; + File = new FileFd(Queue->DestFile,FileFd::WriteAny); + if (_error->PendingError() == true) + return ERROR_NOT_FROM_SERVER; + + FailFile = Queue->DestFile; + FailFile.c_str(); // Make sure we dont do a malloc in the signal handler + FailFd = File->Fd(); + FailTime = Server->Date; + + if (Server->InitHashes(*File) == false) + { + _error->Errno("read",_("Problem hashing file")); + return ERROR_NOT_FROM_SERVER; + } + if (Server->StartPos > 0) + Res.ResumePoint = Server->StartPos; + + SetNonBlock(File->Fd(),true); + return FILE_IS_OPEN; +} + /*}}}*/ +// ServerMethod::SigTerm - Handle a fatal signal /*{{{*/ +// --------------------------------------------------------------------- +/* This closes and timestamps the open file. This is necessary to get + resume behavoir on user abort */ +void ServerMethod::SigTerm(int) +{ + if (FailFd == -1) + _exit(100); + + struct timeval times[2]; + times[0].tv_sec = FailTime; + times[1].tv_sec = FailTime; + times[0].tv_usec = times[1].tv_usec = 0; + utimes(FailFile.c_str(), times); + close(FailFd); + + _exit(100); +} + /*}}}*/ +// ServerMethod::Fetch - Fetch an item /*{{{*/ +// --------------------------------------------------------------------- +/* This adds an item to the pipeline. We keep the pipeline at a fixed + depth. */ +bool ServerMethod::Fetch(FetchItem *) +{ + if (Server == 0) + return true; + + // Queue the requests + int Depth = -1; + for (FetchItem *I = Queue; I != 0 && Depth < (signed)PipelineDepth; + I = I->Next, Depth++) + { + // If pipelining is disabled, we only queue 1 request + if (Server->Pipeline == false && Depth >= 0) + break; + + // Make sure we stick with the same server + if (Server->Comp(I->Uri) == false) + break; + if (QueueBack == I) + { + QueueBack = I->Next; + SendReq(I); + continue; + } + } + + return true; +} + /*}}}*/ +// ServerMethod::Loop - Main loop /*{{{*/ +int ServerMethod::Loop() +{ + typedef vector<string> StringVector; + typedef vector<string>::iterator StringVectorIterator; + map<string, StringVector> Redirected; + + signal(SIGTERM,SigTerm); + signal(SIGINT,SigTerm); + + Server = 0; + + int FailCounter = 0; + while (1) + { + // We have no commands, wait for some to arrive + if (Queue == 0) + { + if (WaitFd(STDIN_FILENO) == false) + return 0; + } + + /* Run messages, we can accept 0 (no message) if we didn't + do a WaitFd above.. Otherwise the FD is closed. */ + int Result = Run(true); + if (Result != -1 && (Result != 0 || Queue == 0)) + { + if(FailReason.empty() == false || + _config->FindB("Acquire::http::DependOnSTDIN", true) == true) + return 100; + else + return 0; + } + + if (Queue == 0) + continue; + + // Connect to the server + if (Server == 0 || Server->Comp(Queue->Uri) == false) + { + delete Server; + Server = CreateServerState(Queue->Uri); + } + /* If the server has explicitly said this is the last connection + then we pre-emptively shut down the pipeline and tear down + the connection. This will speed up HTTP/1.0 servers a tad + since we don't have to wait for the close sequence to + complete */ + if (Server->Persistent == false) + Server->Close(); + + // Reset the pipeline + if (Server->IsOpen() == false) + QueueBack = Queue; + + // Connnect to the host + if (Server->Open() == false) + { + Fail(true); + delete Server; + Server = 0; + continue; + } + + // Fill the pipeline. + Fetch(0); + + // Fetch the next URL header data from the server. + switch (Server->RunHeaders(File)) + { + case ServerState::RUN_HEADERS_OK: + break; + + // The header data is bad + case ServerState::RUN_HEADERS_PARSE_ERROR: + { + _error->Error(_("Bad header data")); + Fail(true); + RotateDNS(); + continue; + } + + // The server closed a connection during the header get.. + default: + case ServerState::RUN_HEADERS_IO_ERROR: + { + FailCounter++; + _error->Discard(); + Server->Close(); + Server->Pipeline = false; + + if (FailCounter >= 2) + { + Fail(_("Connection failed"),true); + FailCounter = 0; + } + + RotateDNS(); + continue; + } + }; + + // Decide what to do. + FetchResult Res; + Res.Filename = Queue->DestFile; + switch (DealWithHeaders(Res)) + { + // Ok, the file is Open + case FILE_IS_OPEN: + { + URIStart(Res); + + // Run the data + bool Result = true; + if (Server->HaveContent) + Result = Server->RunData(File); + + /* If the server is sending back sizeless responses then fill in + the size now */ + if (Res.Size == 0) + Res.Size = File->Size(); + + // Close the file, destroy the FD object and timestamp it + FailFd = -1; + delete File; + File = 0; + + // Timestamp + struct timeval times[2]; + times[0].tv_sec = times[1].tv_sec = Server->Date; + times[0].tv_usec = times[1].tv_usec = 0; + utimes(Queue->DestFile.c_str(), times); + + // Send status to APT + if (Result == true) + { + Res.TakeHashes(*Server->GetHashes()); + URIDone(Res); + } + else + { + if (Server->IsOpen() == false) + { + FailCounter++; + _error->Discard(); + Server->Close(); + + if (FailCounter >= 2) + { + Fail(_("Connection failed"),true); + FailCounter = 0; + } + + QueueBack = Queue; + } + else + Fail(true); + } + break; + } + + // IMS hit + case IMS_HIT: + { + URIDone(Res); + break; + } + + // Hard server error, not found or something + case ERROR_UNRECOVERABLE: + { + Fail(); + break; + } + + // Hard internal error, kill the connection and fail + case ERROR_NOT_FROM_SERVER: + { + delete File; + File = 0; + + Fail(); + RotateDNS(); + Server->Close(); + break; + } + + // We need to flush the data, the header is like a 404 w/ error text + case ERROR_WITH_CONTENT_PAGE: + { + Fail(); + + // Send to content to dev/null + File = new FileFd("/dev/null",FileFd::WriteExists); + Server->RunData(File); + delete File; + File = 0; + break; + } + + // Try again with a new URL + case TRY_AGAIN_OR_REDIRECT: + { + // Clear rest of response if there is content + if (Server->HaveContent) + { + File = new FileFd("/dev/null",FileFd::WriteExists); + Server->RunData(File); + delete File; + File = 0; + } + + /* Detect redirect loops. No more redirects are allowed + after the same URI is seen twice in a queue item. */ + StringVector &R = Redirected[Queue->DestFile]; + bool StopRedirects = false; + if (R.empty() == true) + R.push_back(Queue->Uri); + else if (R[0] == "STOP" || R.size() > 10) + StopRedirects = true; + else + { + for (StringVectorIterator I = R.begin(); I != R.end(); ++I) + if (Queue->Uri == *I) + { + R[0] = "STOP"; + break; + } + + R.push_back(Queue->Uri); + } + + if (StopRedirects == false) + Redirect(NextURI); + else + Fail(); + + break; + } + + default: + Fail(_("Internal error")); + break; + } + + FailCounter = 0; + } + + return 0; +} + /*}}}*/ |