src/auth/AclMaxUserIp.cc

   1 /*
   2  * Copyright (C) 1996-2019 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 /* DEBUG: section 28    Access Control */
  10
  11 #include "squid.h"
  12 #include "acl/FilledChecklist.h"
  13 #include "auth/Acl.h"
  14 #include "auth/AclMaxUserIp.h"
  15 #include "auth/UserRequest.h"
  16 #include "ConfigParser.h"
  17 #include "Debug.h"
  18 #include "Parsing.h"
  19 #include "wordlist.h"
  20
  21 ACLMaxUserIP::ACLMaxUserIP(char const *theClass) :
  22     class_(theClass),
  23     maximum(0)
  24 {}
  25
  26 ACL *
  27 ACLMaxUserIP::clone() const
  28 {
  29     return new ACLMaxUserIP(*this);
  30 }
  31
  32 char const *
  33 ACLMaxUserIP::typeString() const
  34 {
  35     return class_;
  36 }
  37
  38 bool
  39 ACLMaxUserIP::empty() const
  40 {
  41     return false;
  42 }
  43
  44 bool
  45 ACLMaxUserIP::valid() const
  46 {
  47     return maximum > 0;
  48 }
  49
  50 const Acl::Options &
  51 ACLMaxUserIP::options()
  52 {
  53     static const Acl::BooleanOption BeStrict;
  54     static const Acl::Options MyOptions = { { "-s", &BeStrict } };
  55     BeStrict.linkWith(&beStrict);
  56     return MyOptions;
  57 }
  58
  59 void
  60 ACLMaxUserIP::parse()
  61 {
  62     if (maximum) {
  63         debugs(28, DBG_IMPORTANT, "Attempting to alter already set User max IP acl");
  64         return;
  65     }
  66
  67     char *t = ConfigParser::strtokFile();
  68
  69     if (!t)
  70         return;
  71
  72     debugs(28, 5, "aclParseUserMaxIP: First token is " << t);
  73
  74     maximum = xatoi(t);
  75
  76     debugs(28, 5, "aclParseUserMaxIP: Max IP address's " << maximum);
  77
  78     return;
  79 }
  80
  81 /*
  82  * aclMatchUserMaxIP - check for users logging in from multiple IP's
  83  * 0 : No match
  84  * 1 : Match
  85  */
  86 int
  87 ACLMaxUserIP::match(Auth::UserRequest::Pointer auth_user_request, Ip::Address const &src_addr)
  88 {
  89     /*
  90      * the logic for flush the ip list when the limit is hit vs keep
  91      * it sorted in most recent access order and just drop the oldest
  92      * one off is currently undecided (RBC)
  93      */
  94
  95     if (authenticateAuthUserRequestIPCount(auth_user_request) <= maximum)
  96         return 0;
  97
  98     debugs(28, DBG_IMPORTANT, "aclMatchUserMaxIP: user '" << auth_user_request->username() << "' tries to use too many IP addresses (max " << maximum << " allowed)!");
  99
 100     /* this is a match */
 101     if (beStrict) {
 102         /*
 103          * simply deny access - the user name is already associated with
 104          * the request
 105          */
 106         /* remove _this_ ip, as it is the culprit for going over the limit */
 107         authenticateAuthUserRequestRemoveIp(auth_user_request, src_addr);
 108         debugs(28, 4, "aclMatchUserMaxIP: Denying access in strict mode");
 109     } else {
 110         /*
 111          * non-strict - remove some/all of the cached entries
 112          * ie to allow the user to move machines easily
 113          */
 114         authenticateAuthUserRequestClearIp(auth_user_request);
 115         debugs(28, 4, "aclMatchUserMaxIP: Denying access in non-strict mode - flushing the user ip cache");
 116     }
 117
 118     return 1;
 119 }
 120
 121 int
 122 ACLMaxUserIP::match(ACLChecklist *cl)
 123 {
 124     ACLFilledChecklist *checklist = Filled(cl);
 125     allow_t answer = AuthenticateAcl(checklist);
 126     int ti;
 127
 128     // convert to tri-state ACL match 1,0,-1
 129     switch (answer) {
 130     case ACCESS_ALLOWED:
 131         // check for a match
 132         ti = match(checklist->auth_user_request, checklist->src_addr);
 133         checklist->auth_user_request = NULL;
 134         return ti;
 135
 136     case ACCESS_DENIED:
 137         return 0; // non-match
 138
 139     case ACCESS_DUNNO:
 140     case ACCESS_AUTH_REQUIRED:
 141     default:
 142         // If the answer is not allowed or denied (matches/not matches) and
 143         // async authentication is not in progress, then we are done.
 144         if (checklist->keepMatching())
 145             checklist->markFinished(answer, "AuthenticateAcl exception");
 146         return -1; // other
 147     }
 148 }
 149
 150 SBufList
 151 ACLMaxUserIP::dump() const
 152 {
 153     SBufList sl;
 154     if (!maximum)
 155         return sl;
 156     SBuf s;
 157     s.Printf("%d", maximum);
 158     sl.push_back(s);
 159     return sl;
 160 }
 161