1 // Copyright 2010 The Kyua Authors. 2 // All rights reserved. 3 // 4 // Redistribution and use in source and binary forms, with or without 5 // modification, are permitted provided that the following conditions are 6 // met: 7 // 8 // * Redistributions of source code must retain the above copyright 9 // notice, this list of conditions and the following disclaimer. 10 // * Redistributions in binary form must reproduce the above copyright 11 // notice, this list of conditions and the following disclaimer in the 12 // documentation and/or other materials provided with the distribution. 13 // * Neither the name of Google Inc. nor the names of its contributors 14 // may be used to endorse or promote products derived from this software 15 // without specific prior written permission. 16 // 17 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 18 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 19 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 20 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 21 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 22 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 23 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 27 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 29 #include "utils/passwd.hpp" 30 31 extern "C" { 32 #include <sys/types.h> 33 34 #include <pwd.h> 35 #include <unistd.h> 36 } 37 38 #include <stdexcept> 39 40 #include "utils/format/macros.hpp" 41 #include "utils/logging/macros.hpp" 42 #include "utils/optional.ipp" 43 #include "utils/sanity.hpp" 44 45 namespace passwd_ns = utils::passwd; 46 47 48 namespace { 49 50 51 /// If defined, replaces the value returned by current_user(). 52 static utils::optional< passwd_ns::user > fake_current_user; 53 54 55 /// If not empty, defines the current set of mock users. 56 static std::vector< passwd_ns::user > mock_users; 57 58 59 /// Formats a user for logging purposes. 60 /// 61 /// \param user The user to format. 62 /// 63 /// \return The user as a string. 64 static std::string 65 format_user(const passwd_ns::user& user) 66 { 67 return F("name=%s, uid=%s, gid=%s") % user.name % user.uid % user.gid; 68 } 69 70 71 } // anonymous namespace 72 73 74 /// Constructs a new user. 75 /// 76 /// \param name_ The name of the user. 77 /// \param uid_ The user identifier. 78 /// \param gid_ The login group identifier. 79 passwd_ns::user::user(const std::string& name_, const unsigned int uid_, 80 const unsigned int gid_) : 81 name(name_), 82 uid(uid_), 83 gid(gid_) 84 { 85 } 86 87 88 /// Checks if the user has superpowers or not. 89 /// 90 /// \return True if the user is root, false otherwise. 91 bool 92 passwd_ns::user::is_root(void) const 93 { 94 return uid == 0; 95 } 96 97 98 /// Gets the current user. 99 /// 100 /// \return The current user. 101 passwd_ns::user 102 passwd_ns::current_user(void) 103 { 104 if (fake_current_user) { 105 const user u = fake_current_user.get(); 106 LD(F("Current user is fake: %s") % format_user(u)); 107 return u; 108 } else { 109 const user u = find_user_by_uid(::getuid()); 110 LD(F("Current user is: %s") % format_user(u)); 111 return u; 112 } 113 } 114 115 116 /// Gets information about a user by its name. 117 /// 118 /// \param name The name of the user to query. 119 /// 120 /// \return The information about the user. 121 /// 122 /// \throw std::runtime_error If the user does not exist. 123 passwd_ns::user 124 passwd_ns::find_user_by_name(const std::string& name) 125 { 126 if (mock_users.empty()) { 127 const struct ::passwd* pw = ::getpwnam(name.c_str()); 128 if (pw == NULL) 129 throw std::runtime_error(F("Failed to get information about the " 130 "user '%s'") % name); 131 INV(pw->pw_name == name); 132 return user(pw->pw_name, pw->pw_uid, pw->pw_gid); 133 } else { 134 for (std::vector< user >::const_iterator iter = mock_users.begin(); 135 iter != mock_users.end(); iter++) { 136 if ((*iter).name == name) 137 return *iter; 138 } 139 throw std::runtime_error(F("Failed to get information about the " 140 "user '%s'") % name); 141 } 142 } 143 144 145 /// Gets information about a user by its identifier. 146 /// 147 /// \param uid The identifier of the user to query. 148 /// 149 /// \return The information about the user. 150 /// 151 /// \throw std::runtime_error If the user does not exist. 152 passwd_ns::user 153 passwd_ns::find_user_by_uid(const unsigned int uid) 154 { 155 if (mock_users.empty()) { 156 const struct ::passwd* pw = ::getpwuid(uid); 157 if (pw == NULL) 158 throw std::runtime_error(F("Failed to get information about the " 159 "user with UID %s") % uid); 160 INV(pw->pw_uid == uid); 161 return user(pw->pw_name, pw->pw_uid, pw->pw_gid); 162 } else { 163 for (std::vector< user >::const_iterator iter = mock_users.begin(); 164 iter != mock_users.end(); iter++) { 165 if ((*iter).uid == uid) 166 return *iter; 167 } 168 throw std::runtime_error(F("Failed to get information about the " 169 "user with UID %s") % uid); 170 } 171 } 172 173 174 /// Overrides the current user for testing purposes. 175 /// 176 /// This DOES NOT change the current privileges! 177 /// 178 /// \param new_current_user The new current user. 179 void 180 passwd_ns::set_current_user_for_testing(const user& new_current_user) 181 { 182 fake_current_user = new_current_user; 183 } 184 185 186 /// Overrides the current set of users for testing purposes. 187 /// 188 /// \param users The new users set. Cannot be empty. 189 void 190 passwd_ns::set_mock_users_for_testing(const std::vector< user >& users) 191 { 192 PRE(!users.empty()); 193 mock_users = users; 194 } 195