1 /* 2 * Copyright (c) 1984 through 2008, William LeFebvre 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are met: 7 * 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 11 * * Redistributions in binary form must reproduce the above 12 * copyright notice, this list of conditions and the following disclaimer 13 * in the documentation and/or other materials provided with the 14 * distribution. 15 * 16 * * Neither the name of William LeFebvre nor the names of other 17 * contributors may be used to endorse or promote products derived from 18 * this software without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 23 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 24 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 25 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 26 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 30 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 /* 34 * Top users/processes display for Unix 35 * Version 3 36 */ 37 38 /* 39 * Username translation code for top. 40 * 41 * These routines handle uid to username mapping. They use a hash table to 42 * reduce reading overhead. Entries are refreshed every EXPIRETIME seconds. 43 * 44 * The old ad-hoc hash functions have been replaced with something a little 45 * more formal and (hopefully) more robust (found in hash.c) 46 */ 47 48 #include "os.h" 49 50 #include <pwd.h> 51 52 #include "top.h" 53 #include "utils.h" 54 #include "hash.h" 55 56 #define EXPIRETIME (60 * 5) 57 58 /* we need some sort of idea how long usernames can be */ 59 #ifndef MAXLOGNAME 60 #ifdef _POSIX_LOGIN_NAME_MAX 61 #define MAXLOGNAME _POSIX_LOGIN_NAME_MAX 62 #else 63 #define MAXLOGNAME 9 64 #endif 65 #endif 66 67 struct hash_data { 68 int uid; 69 char name[MAXLOGNAME]; /* big enough? */ 70 time_t expire; 71 }; 72 73 hash_table *userhash; 74 75 76 void 77 init_username() 78 79 { 80 userhash = hash_create(211); 81 } 82 83 char * 84 username(int uid) 85 86 { 87 struct hash_data *data; 88 struct passwd *pw; 89 time_t now; 90 91 /* what time is it? */ 92 now = time(NULL); 93 94 /* get whatever is in the cache */ 95 data = hash_lookup_uint(userhash, (unsigned int)uid); 96 97 /* if we had a cache miss, then create space for a new entry */ 98 if (data == NULL) 99 { 100 /* make space */ 101 data = (struct hash_data *)malloc(sizeof(struct hash_data)); 102 103 /* fill in some data, including an already expired time */ 104 data->uid = uid; 105 data->expire = (time_t)0; 106 107 /* add it to the hash: the rest gets filled in later */ 108 hash_add_uint(userhash, uid, data); 109 } 110 111 /* Now data points to the correct hash entry for "uid". If this is 112 a new entry, then expire is 0 and the next test will be true. */ 113 if (data->expire <= now) 114 { 115 if ((pw = getpwuid(uid)) != NULL) 116 { 117 strncpy(data->name, pw->pw_name, MAXLOGNAME-1); 118 data->expire = now + EXPIRETIME; 119 dprintf("username: updating %d with %s, expires %d\n", 120 data->uid, data->name, data->expire); 121 } 122 else 123 { 124 /* username doesnt exist ... so invent one */ 125 snprintf(data->name, sizeof(data->name), "%d", uid); 126 data->expire = now + EXPIRETIME; 127 dprintf("username: updating %d with %s, expires %d\n", 128 data->uid, data->name, data->expire); 129 } 130 } 131 132 /* return what we have */ 133 return data->name; 134 } 135 136 int 137 userid(char *username) 138 139 { 140 struct passwd *pwd; 141 142 if ((pwd = getpwnam(username)) == NULL) 143 { 144 return(-1); 145 } 146 147 /* return our result */ 148 return(pwd->pw_uid); 149 } 150 151