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
init_username()77 init_username()
78
79 {
80 userhash = hash_create(211);
81 }
82
83 char *
username(int uid)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
userid(char * username)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