methods/server.h

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 /* ######################################################################
   4
   5    Classes dealing with the abstraction of talking to a end via a text
   6    protocol like HTTP (which is used by the http and https methods)
   7
   8    ##################################################################### */
   9                                                                         /*}}}*/
  10
  11 #ifndef APT_SERVER_H
  12 #define APT_SERVER_H
  13
  14 #include <apt-pkg/strutl.h>
  15 #include "aptmethod.h"
  16
  17 #include <time.h>
  18 #include <iostream>
  19 #include <string>
  20 #include <memory>
  21
  22 using std::cout;
  23 using std::endl;
  24
  25 class Hashes;
  26 class ServerMethod;
  27 class FileFd;
  28
  29 struct ServerState
  30 {
  31    // This is the last parsed Header Line
  32    unsigned int Major;
  33    unsigned int Minor;
  34    unsigned int Result;
  35    char Code[360];
  36
  37    // These are some statistics from the last parsed header lines
  38
  39    // total size of the usable content (aka: the file)
  40    unsigned long long TotalFileSize;
  41    // size we actually download (can be smaller than Size if we have partial content)
  42    unsigned long long DownloadSize;
  43    // size of junk content (aka: server error pages)
  44    unsigned long long JunkSize;
  45    // The start of the data (for partial content)
  46    unsigned long long StartPos;
  47
  48    time_t Date;
  49    bool HaveContent;
  50    enum {Chunked,Stream,Closes} Encoding;
  51    enum {Header, Data} State;
  52    bool Persistent;
  53    bool PipelineAllowed;
  54    std::string Location;
  55
  56    // This is a Persistent attribute of the server itself.
  57    bool Pipeline;
  58    URI ServerName;
  59    URI Proxy;
  60    unsigned long TimeOut;
  61
  62    unsigned long long MaximumSize;
  63
  64    protected:
  65    ServerMethod *Owner;
  66
  67    virtual bool ReadHeaderLines(std::string &Data) = 0;
  68    virtual bool LoadNextResponse(bool const ToFile, FileFd * const File) = 0;
  69
  70    public:
  71    bool HeaderLine(std::string Line);
  72
  73    /** \brief Result of the header acquire */
  74    enum RunHeadersResult {
  75       /** \brief Header ok */
  76       RUN_HEADERS_OK,
  77       /** \brief IO error while retrieving */
  78       RUN_HEADERS_IO_ERROR,
  79       /** \brief Parse error after retrieving */
  80       RUN_HEADERS_PARSE_ERROR
  81    };
  82    /** \brief Get the headers before the data */
  83    RunHeadersResult RunHeaders(FileFd * const File, const std::string &Uri);
  84    bool AddPartialFileToHashes(FileFd &File);
  85
  86    bool Comp(URI Other) const {return Other.Host == ServerName.Host && Other.Port == ServerName.Port;};
  87    virtual void Reset() {Major = 0; Minor = 0; Result = 0; Code[0] = '\0'; TotalFileSize = 0; JunkSize = 0;
  88                  StartPos = 0; Encoding = Closes; time(&Date); HaveContent = false;
  89                  State = Header; Persistent = false; Pipeline = false; MaximumSize = 0; PipelineAllowed = true;};
  90    virtual bool WriteResponse(std::string const &Data) = 0;
  91
  92    /** \brief Transfer the data from the socket */
  93    virtual bool RunData(FileFd * const File) = 0;
  94
  95    virtual bool Open() = 0;
  96    virtual bool IsOpen() = 0;
  97    virtual bool Close() = 0;
  98    virtual bool InitHashes(HashStringList const &ExpectedHashes) = 0;
  99    virtual Hashes * GetHashes() = 0;
 100    virtual bool Die(FileFd &File) = 0;
 101    virtual bool Flush(FileFd * const File) = 0;
 102    virtual bool Go(bool ToFile, FileFd * const File) = 0;
 103
 104    ServerState(URI Srv, ServerMethod *Owner);
 105    virtual ~ServerState() {};
 106 };
 107
 108 class ServerMethod : public aptMethod
 109 {
 110    protected:
 111    virtual bool Fetch(FetchItem *) APT_OVERRIDE;
 112
 113    std::unique_ptr<ServerState> Server;
 114    std::string NextURI;
 115    FileFd *File;
 116
 117    unsigned long PipelineDepth;
 118    bool AllowRedirect;
 119
 120    // Find the biggest item in the fetch queue for the checking of the maximum
 121    // size
 122    unsigned long long FindMaximumObjectSizeInQueue() const APT_PURE;
 123
 124    public:
 125    bool Debug;
 126
 127    /** \brief Result of the header parsing */
 128    enum DealWithHeadersResult {
 129       /** \brief The file is open and ready */
 130       FILE_IS_OPEN,
 131       /** \brief We got a IMS hit, the file has not changed */
 132       IMS_HIT,
 133       /** \brief The server reported a unrecoverable error */
 134       ERROR_UNRECOVERABLE,
 135       /** \brief The server reported a error with a error content page */
 136       ERROR_WITH_CONTENT_PAGE,
 137       /** \brief An error on the client side */
 138       ERROR_NOT_FROM_SERVER,
 139       /** \brief A redirect or retry request */
 140       TRY_AGAIN_OR_REDIRECT
 141    };
 142    /** \brief Handle the retrieved header data */
 143    DealWithHeadersResult DealWithHeaders(FetchResult &Res);
 144
 145    // In the event of a fatal signal this file will be closed and timestamped.
 146    static std::string FailFile;
 147    static int FailFd;
 148    static time_t FailTime;
 149    static APT_NORETURN void SigTerm(int);
 150
 151    virtual bool Flush() { return Server->Flush(File); };
 152
 153    int Loop();
 154
 155    virtual void SendReq(FetchItem *Itm) = 0;
 156    virtual std::unique_ptr<ServerState> CreateServerState(URI const &uri) = 0;
 157    virtual void RotateDNS() = 0;
 158
 159    ServerMethod(char const * const Binary, char const * const Ver,unsigned long const Flags);
 160    virtual ~ServerMethod() {};
 161 };
 162
 163 #endif