| 1 | // -*- mode: cpp; mode: fold -*- |
| 2 | // Description /*{{{*/ |
| 3 | // $Id: connect.cc,v 1.10.2.1 2004/01/16 18:58:50 mdz Exp $ |
| 4 | /* ###################################################################### |
| 5 | |
| 6 | Connect - Replacement connect call |
| 7 | |
| 8 | This was originally authored by Jason Gunthorpe <jgg@debian.org> |
| 9 | and is placed in the Public Domain, do with it what you will. |
| 10 | |
| 11 | ##################################################################### */ |
| 12 | /*}}}*/ |
| 13 | // Include Files /*{{{*/ |
| 14 | #include <config.h> |
| 15 | |
| 16 | #include <apt-pkg/error.h> |
| 17 | #include <apt-pkg/fileutl.h> |
| 18 | #include <apt-pkg/strutl.h> |
| 19 | #include <apt-pkg/acquire-method.h> |
| 20 | #include <apt-pkg/configuration.h> |
| 21 | #include <apt-pkg/srvrec.h> |
| 22 | |
| 23 | #include <stdio.h> |
| 24 | #include <errno.h> |
| 25 | #include <unistd.h> |
| 26 | #include <sstream> |
| 27 | #include <string.h> |
| 28 | #include<set> |
| 29 | #include<string> |
| 30 | |
| 31 | // Internet stuff |
| 32 | #include <netinet/in.h> |
| 33 | #include <sys/socket.h> |
| 34 | #include <arpa/inet.h> |
| 35 | #include <netdb.h> |
| 36 | |
| 37 | #include "connect.h" |
| 38 | #include "rfc2553emu.h" |
| 39 | #include <apti18n.h> |
| 40 | /*}}}*/ |
| 41 | |
| 42 | static std::string LastHost; |
| 43 | static int LastPort = 0; |
| 44 | static struct addrinfo *LastHostAddr = 0; |
| 45 | static struct addrinfo *LastUsed = 0; |
| 46 | |
| 47 | static std::vector<SrvRec> SrvRecords; |
| 48 | |
| 49 | // Set of IP/hostnames that we timed out before or couldn't resolve |
| 50 | static std::set<std::string> bad_addr; |
| 51 | |
| 52 | // RotateDNS - Select a new server from a DNS rotation /*{{{*/ |
| 53 | // --------------------------------------------------------------------- |
| 54 | /* This is called during certain errors in order to recover by selecting a |
| 55 | new server */ |
| 56 | void RotateDNS() |
| 57 | { |
| 58 | if (LastUsed != 0 && LastUsed->ai_next != 0) |
| 59 | LastUsed = LastUsed->ai_next; |
| 60 | else |
| 61 | LastUsed = LastHostAddr; |
| 62 | } |
| 63 | /*}}}*/ |
| 64 | // DoConnect - Attempt a connect operation /*{{{*/ |
| 65 | // --------------------------------------------------------------------- |
| 66 | /* This helper function attempts a connection to a single address. */ |
| 67 | static bool DoConnect(struct addrinfo *Addr,std::string Host, |
| 68 | unsigned long TimeOut,int &Fd,pkgAcqMethod *Owner) |
| 69 | { |
| 70 | // Show a status indicator |
| 71 | char Name[NI_MAXHOST]; |
| 72 | char Service[NI_MAXSERV]; |
| 73 | |
| 74 | Name[0] = 0; |
| 75 | Service[0] = 0; |
| 76 | getnameinfo(Addr->ai_addr,Addr->ai_addrlen, |
| 77 | Name,sizeof(Name),Service,sizeof(Service), |
| 78 | NI_NUMERICHOST|NI_NUMERICSERV); |
| 79 | Owner->Status(_("Connecting to %s (%s)"),Host.c_str(),Name); |
| 80 | |
| 81 | // if that addr did timeout before, we do not try it again |
| 82 | if(bad_addr.find(std::string(Name)) != bad_addr.end()) |
| 83 | return false; |
| 84 | |
| 85 | /* If this is an IP rotation store the IP we are using.. If something goes |
| 86 | wrong this will get tacked onto the end of the error message */ |
| 87 | if (LastHostAddr->ai_next != 0) |
| 88 | { |
| 89 | std::stringstream ss; |
| 90 | ioprintf(ss, _("[IP: %s %s]"),Name,Service); |
| 91 | Owner->SetIP(ss.str()); |
| 92 | } |
| 93 | |
| 94 | // Get a socket |
| 95 | if ((Fd = socket(Addr->ai_family,Addr->ai_socktype, |
| 96 | Addr->ai_protocol)) < 0) |
| 97 | return _error->Errno("socket",_("Could not create a socket for %s (f=%u t=%u p=%u)"), |
| 98 | Name,Addr->ai_family,Addr->ai_socktype,Addr->ai_protocol); |
| 99 | |
| 100 | SetNonBlock(Fd,true); |
| 101 | if (connect(Fd,Addr->ai_addr,Addr->ai_addrlen) < 0 && |
| 102 | errno != EINPROGRESS) |
| 103 | return _error->Errno("connect",_("Cannot initiate the connection " |
| 104 | "to %s:%s (%s)."),Host.c_str(),Service,Name); |
| 105 | |
| 106 | /* This implements a timeout for connect by opening the connection |
| 107 | nonblocking */ |
| 108 | if (WaitFd(Fd,true,TimeOut) == false) { |
| 109 | bad_addr.insert(bad_addr.begin(), std::string(Name)); |
| 110 | Owner->SetFailReason("Timeout"); |
| 111 | return _error->Error(_("Could not connect to %s:%s (%s), " |
| 112 | "connection timed out"),Host.c_str(),Service,Name); |
| 113 | } |
| 114 | |
| 115 | // Check the socket for an error condition |
| 116 | unsigned int Err; |
| 117 | unsigned int Len = sizeof(Err); |
| 118 | if (getsockopt(Fd,SOL_SOCKET,SO_ERROR,&Err,&Len) != 0) |
| 119 | return _error->Errno("getsockopt",_("Failed")); |
| 120 | |
| 121 | if (Err != 0) |
| 122 | { |
| 123 | errno = Err; |
| 124 | if(errno == ECONNREFUSED) |
| 125 | Owner->SetFailReason("ConnectionRefused"); |
| 126 | else if (errno == ETIMEDOUT) |
| 127 | Owner->SetFailReason("ConnectionTimedOut"); |
| 128 | bad_addr.insert(bad_addr.begin(), std::string(Name)); |
| 129 | return _error->Errno("connect",_("Could not connect to %s:%s (%s)."),Host.c_str(), |
| 130 | Service,Name); |
| 131 | } |
| 132 | |
| 133 | return true; |
| 134 | } |
| 135 | /*}}}*/ |
| 136 | // Connect to a given Hostname /*{{{*/ |
| 137 | static bool ConnectToHostname(std::string const &Host, int const Port, |
| 138 | const char * const Service, int DefPort, int &Fd, |
| 139 | unsigned long const TimeOut, pkgAcqMethod * const Owner) |
| 140 | { |
| 141 | // Convert the port name/number |
| 142 | char ServStr[300]; |
| 143 | if (Port != 0) |
| 144 | snprintf(ServStr,sizeof(ServStr),"%i", Port); |
| 145 | else |
| 146 | snprintf(ServStr,sizeof(ServStr),"%s", Service); |
| 147 | |
| 148 | /* We used a cached address record.. Yes this is against the spec but |
| 149 | the way we have setup our rotating dns suggests that this is more |
| 150 | sensible */ |
| 151 | if (LastHost != Host || LastPort != Port) |
| 152 | { |
| 153 | Owner->Status(_("Connecting to %s"),Host.c_str()); |
| 154 | |
| 155 | // Free the old address structure |
| 156 | if (LastHostAddr != 0) |
| 157 | { |
| 158 | freeaddrinfo(LastHostAddr); |
| 159 | LastHostAddr = 0; |
| 160 | LastUsed = 0; |
| 161 | } |
| 162 | |
| 163 | // We only understand SOCK_STREAM sockets. |
| 164 | struct addrinfo Hints; |
| 165 | memset(&Hints,0,sizeof(Hints)); |
| 166 | Hints.ai_socktype = SOCK_STREAM; |
| 167 | Hints.ai_flags = 0; |
| 168 | if (_config->FindB("Acquire::Connect::IDN", true) == true) |
| 169 | Hints.ai_flags |= AI_IDN; |
| 170 | // see getaddrinfo(3): only return address if system has such a address configured |
| 171 | // useful if system is ipv4 only, to not get ipv6, but that fails if the system has |
| 172 | // no address configured: e.g. offline and trying to connect to localhost. |
| 173 | if (_config->FindB("Acquire::Connect::AddrConfig", true) == true) |
| 174 | Hints.ai_flags |= AI_ADDRCONFIG; |
| 175 | Hints.ai_protocol = 0; |
| 176 | |
| 177 | if(_config->FindB("Acquire::ForceIPv4", false) == true) |
| 178 | Hints.ai_family = AF_INET; |
| 179 | else if(_config->FindB("Acquire::ForceIPv6", false) == true) |
| 180 | Hints.ai_family = AF_INET6; |
| 181 | else |
| 182 | Hints.ai_family = AF_UNSPEC; |
| 183 | |
| 184 | // if we couldn't resolve the host before, we don't try now |
| 185 | if(bad_addr.find(Host) != bad_addr.end()) |
| 186 | return _error->Error(_("Could not resolve '%s'"),Host.c_str()); |
| 187 | |
| 188 | // Resolve both the host and service simultaneously |
| 189 | while (1) |
| 190 | { |
| 191 | int Res; |
| 192 | if ((Res = getaddrinfo(Host.c_str(),ServStr,&Hints,&LastHostAddr)) != 0 || |
| 193 | LastHostAddr == 0) |
| 194 | { |
| 195 | if (Res == EAI_NONAME || Res == EAI_SERVICE) |
| 196 | { |
| 197 | if (DefPort != 0) |
| 198 | { |
| 199 | snprintf(ServStr, sizeof(ServStr), "%i", DefPort); |
| 200 | DefPort = 0; |
| 201 | continue; |
| 202 | } |
| 203 | bad_addr.insert(bad_addr.begin(), Host); |
| 204 | Owner->SetFailReason("ResolveFailure"); |
| 205 | return _error->Error(_("Could not resolve '%s'"),Host.c_str()); |
| 206 | } |
| 207 | |
| 208 | if (Res == EAI_AGAIN) |
| 209 | { |
| 210 | Owner->SetFailReason("TmpResolveFailure"); |
| 211 | return _error->Error(_("Temporary failure resolving '%s'"), |
| 212 | Host.c_str()); |
| 213 | } |
| 214 | if (Res == EAI_SYSTEM) |
| 215 | return _error->Errno("getaddrinfo", _("System error resolving '%s:%s'"), |
| 216 | Host.c_str(),ServStr); |
| 217 | return _error->Error(_("Something wicked happened resolving '%s:%s' (%i - %s)"), |
| 218 | Host.c_str(),ServStr,Res,gai_strerror(Res)); |
| 219 | } |
| 220 | break; |
| 221 | } |
| 222 | |
| 223 | LastHost = Host; |
| 224 | LastPort = Port; |
| 225 | } |
| 226 | |
| 227 | // When we have an IP rotation stay with the last IP. |
| 228 | struct addrinfo *CurHost = LastHostAddr; |
| 229 | if (LastUsed != 0) |
| 230 | CurHost = LastUsed; |
| 231 | |
| 232 | while (CurHost != 0) |
| 233 | { |
| 234 | if (DoConnect(CurHost,Host,TimeOut,Fd,Owner) == true) |
| 235 | { |
| 236 | LastUsed = CurHost; |
| 237 | return true; |
| 238 | } |
| 239 | close(Fd); |
| 240 | Fd = -1; |
| 241 | |
| 242 | // Ignore UNIX domain sockets |
| 243 | do |
| 244 | { |
| 245 | CurHost = CurHost->ai_next; |
| 246 | } |
| 247 | while (CurHost != 0 && CurHost->ai_family == AF_UNIX); |
| 248 | |
| 249 | /* If we reached the end of the search list then wrap around to the |
| 250 | start */ |
| 251 | if (CurHost == 0 && LastUsed != 0) |
| 252 | CurHost = LastHostAddr; |
| 253 | |
| 254 | // Reached the end of the search cycle |
| 255 | if (CurHost == LastUsed) |
| 256 | break; |
| 257 | |
| 258 | if (CurHost != 0) |
| 259 | _error->Discard(); |
| 260 | } |
| 261 | |
| 262 | if (_error->PendingError() == true) |
| 263 | return false; |
| 264 | return _error->Error(_("Unable to connect to %s:%s:"),Host.c_str(),ServStr); |
| 265 | } |
| 266 | /*}}}*/ |
| 267 | // Connect - Connect to a server /*{{{*/ |
| 268 | // --------------------------------------------------------------------- |
| 269 | /* Performs a connection to the server (including SRV record lookup) */ |
| 270 | bool Connect(std::string Host,int Port,const char *Service, |
| 271 | int DefPort,int &Fd, |
| 272 | unsigned long TimeOut,pkgAcqMethod *Owner) |
| 273 | { |
| 274 | if (_error->PendingError() == true) |
| 275 | return false; |
| 276 | |
| 277 | if(LastHost != Host || LastPort != Port) |
| 278 | { |
| 279 | SrvRecords.clear(); |
| 280 | if (_config->FindB("Acquire::EnableSrvRecords", true) == true) |
| 281 | GetSrvRecords(Host, DefPort, SrvRecords); |
| 282 | } |
| 283 | // we have no SrvRecords for this host, connect right away |
| 284 | if(SrvRecords.size() == 0) |
| 285 | return ConnectToHostname(Host, Port, Service, DefPort, Fd, |
| 286 | TimeOut, Owner); |
| 287 | |
| 288 | // try to connect in the priority order of the srv records |
| 289 | while(SrvRecords.size() > 0) |
| 290 | { |
| 291 | // PopFromSrvRecs will also remove the server |
| 292 | Host = PopFromSrvRecs(SrvRecords).target; |
| 293 | if(ConnectToHostname(Host, Port, Service, DefPort, Fd, TimeOut, Owner)) |
| 294 | return true; |
| 295 | } |
| 296 | |
| 297 | return false; |
| 298 | } |