source: trunk/src/sh_port2proc.c@ 185

Last change on this file since 185 was 180, checked in by katerina, 16 years ago

Process lookup (Linux) for open ports (ticket #117). Also fix for minor dnmalloc bug (ticket #119).
File size: 8.5 KB
Line 
1/* SAMHAIN file system integrity testing */
2/* Copyright (C) 2008 Rainer Wichmann */
3/* */
4/* This program is free software; you can redistribute it */
5/* and/or modify */
6/* it under the terms of the GNU General Public License as */
7/* published by */
8/* the Free Software Foundation; either version 2 of the License, or */
9/* (at your option) any later version. */
10/* */
11/* This program is distributed in the hope that it will be useful, */
12/* but WITHOUT ANY WARRANTY; without even the implied warranty of */
13/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */
14/* GNU General Public License for more details. */
15/* */
16/* You should have received a copy of the GNU General Public License */
17/* along with this program; if not, write to the Free Software */
18/* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
19
20#include "config_xor.h"
21
22#include <stdio.h>
23#include <stdlib.h>
24#include <string.h>
25#include <sys/types.h>
26#include <unistd.h>
27
28#ifdef HAVE_DIRENT_H
29#include <dirent.h>
30#define NAMLEN(dirent) sl_strlen((dirent)->d_name)
31#else
32#define dirent direct
33#define NAMLEN(dirent) (dirent)->d_namlen
34#ifdef HAVE_SYS_NDIR_H
35#include <sys/ndir.h>
36#endif
37#ifdef HAVE_SYS_DIR_H
38#include <sys/dir.h>
39#endif
40#ifdef HAVE_NDIR_H
41#include <ndir.h>
42#endif
43#endif
44#define NEED_ADD_DIRENT
45
46#if defined(SH_USE_PORTCHECK) && (defined (SH_WITH_CLIENT) || defined (SH_STANDALONE))
47
48#if defined(__linux__)
49
50#include "samhain.h"
51#include "sh_error_min.h"
52#include "sh_utils.h"
53#include "sh_pthread.h"
54
55#define FIL__ _("sh_port2proc.c")
56
57static size_t sh_minpid = 0x0001;
58static size_t sh_maxpid = 0x8000;
59
60#ifndef HAVE_LSTAT
61#define lstat(x,y) stat(x,y)
62#endif /* HAVE_LSTAT */
63
64#if defined(S_IFLNK) && !defined(S_ISLNK)
65#define S_ISLNK(mode) (((mode) & S_IFMT) == S_IFLNK)
66#else
67#if !defined(S_ISLNK)
68#define S_ISLNK(mode) (0)
69#endif
70#endif
71
72struct sock_store {
73 unsigned long sock;
74 size_t pid;
75 char * path;
76 char * user;
77 struct sock_store * next;
78};
79
80/* /proc:
81 * linux: /proc/pid/exe
82 * freebsd: /proc/pid/file
83 * solaris10: /proc/pid/path/a.out
84 */
85static void get_user_and_path (struct sock_store * add)
86{
87 extern char * sh_unix_getUIDname (int level, uid_t uid, char * out, size_t len);
88
89 char path[128];
90 char * buf;
91 struct stat sbuf;
92 int len;
93 char * tmp;
94
95 sl_snprintf (path, sizeof(path), "/proc/%ld/exe", (unsigned long) add->pid);
96
97 if (0 == retry_lstat(FIL__, __LINE__, path, &sbuf) && S_ISLNK(sbuf.st_mode))
98 {
99 goto linkread;
100 }
101
102 sl_snprintf (path, sizeof(path), "/proc/%ld/file", (unsigned long) add->pid);
103
104 if (0 == retry_lstat(FIL__, __LINE__, path, &sbuf) && S_ISLNK(sbuf.st_mode))
105 {
106 goto linkread;
107 }
108
109 sl_snprintf (path, sizeof(path), "/proc/%ld/path/a.out", (unsigned long) add->pid);
110
111 if (0 == retry_lstat(FIL__, __LINE__, path, &sbuf) && S_ISLNK(sbuf.st_mode))
112 {
113 goto linkread;
114 }
115
116 return;
117
118 linkread:
119
120 buf = SH_ALLOC(PATH_MAX);
121 len = readlink(path, buf, PATH_MAX); /* flawfinder: ignore */
122 len = (len >= PATH_MAX) ? (PATH_MAX-1) : len;
123
124 if (len > 0)
125 {
126 buf[len] = '\0';
127 add->path = buf;
128 }
129 else
130 {
131 SH_FREE(buf);
132 }
133
134 add->user = SH_ALLOC(USER_MAX);
135 tmp = sh_unix_getUIDname (SH_ERR_ALL, sbuf.st_uid, add->user, USER_MAX);
136
137 if (!tmp)
138 sl_snprintf (add->user, USER_MAX, "%ld", (unsigned long) sbuf.st_uid);
139
140 return;
141}
142
143#if defined(__linux__)
144#define PROC_PID_MAX _("/proc/sys/kernel/pid_max")
145
146static int proc_max_pid (size_t * procpid)
147{
148 char * ret;
149 unsigned long pid;
150 FILE * fd;
151 char str[128];
152 char * ptr;
153
154 SL_ENTER(_("proc_max_pid"));
155
156 if (0 == access(PROC_PID_MAX, R_OK)) /* flawfinder: ignore */
157 {
158 if (NULL != (fd = fopen(PROC_PID_MAX, "r")))
159 {
160 str[0] = '\0';
161 ret = fgets(str, 128, fd);
162 if (ret && *str != '\0')
163 {
164 pid = strtoul(str, &ptr, 0);
165 if (*ptr == '\0' || *ptr == '\n')
166 {
167 fclose(fd);
168 *procpid = (size_t) pid;
169 SL_RETURN(0, _("proc_max_pid"));
170 }
171 }
172 fclose(fd);
173 }
174 }
175 SL_RETURN((-1), _("proc_max_pid"));
176}
177#else
178static int proc_max_pid(size_t * procpid)
179{
180 *procpid = sh_maxpid;
181 return 0;
182}
183#endif
184
185static struct sock_store * socklist = NULL;
186
187static void del_sock_all()
188{
189 struct sock_store * del = socklist;
190
191 while (del)
192 {
193 socklist = del->next;
194 if (del->path)
195 SH_FREE(del->path);
196 if (del->user)
197 SH_FREE(del->user);
198 SH_FREE(del);
199 del = socklist;
200 }
201 socklist = NULL;
202 return;
203}
204
205static void add_sock(unsigned long sock, size_t pid)
206{
207 struct sock_store * add = SH_ALLOC(sizeof(struct sock_store));
208
209 add->sock = sock;
210 add->pid = pid;
211 add->path = NULL;
212 add->user = NULL;
213 SH_MUTEX_LOCK(mutex_thread_nolog);
214 get_user_and_path(add);
215 SH_MUTEX_UNLOCK(mutex_thread_nolog);
216 add->next = socklist;
217 socklist = add;
218 return;
219}
220
221static void check_and_add_sock(char * fbuf, size_t pid)
222{
223 if (0 == strncmp(_("socket:["), fbuf, 8))
224 {
225 char * end;
226 unsigned long sock;
227 size_t len = strlen(fbuf);
228 if (fbuf[len-1] == ']')
229 fbuf[len-1] = '\0';
230 sock = strtoul(&fbuf[8], &end, 0);
231 if (*end == '\0' && fbuf[8] != '\0')
232 {
233 add_sock(sock, pid);
234 }
235 }
236}
237
238static void fetch_socks(size_t pid)
239{
240 char path[128];
241 DIR * dir;
242 sl_snprintf(path, sizeof(path), _("/proc/%lu/fd"), (unsigned long) pid);
243
244 dir = opendir(path);
245 if (dir)
246 {
247 struct dirent *entry;
248 while (NULL != (entry = readdir(dir)))
249 {
250 char fpath[384];
251 char fbuf[64];
252 int ret;
253 /* /proc/PID/fd/N-> socket:[15713] */
254 sl_snprintf(fpath, sizeof(fpath), _("%s/%s"), path, entry->d_name);
255 ret = readlink(fpath, fbuf, sizeof(fbuf)-1); /* flawfinder: ignore */
256 if (ret > 0)
257 {
258 fbuf[ret] = '\0';
259 check_and_add_sock(fbuf, pid);
260 }
261 }
262 closedir(dir);
263 }
264}
265
266int sh_port2proc_prepare()
267{
268 size_t i;
269
270 if (0 != proc_max_pid(&sh_maxpid))
271 {
272 SH_MUTEX_LOCK(mutex_thread_nolog);
273 sh_error_handle(SH_ERR_ALL, FIL__, __LINE__, 0, MSG_E_SUBGEN,
274 _("Failed to detect max_pid"),
275 _("sh_port2proc"));
276 SH_MUTEX_UNLOCK(mutex_thread_nolog);
277 SL_RETURN ((-1), _("sh_port2proc"));
278 }
279
280 /* Delete old socket list and re-create it
281 */
282 del_sock_all();
283
284 for (i = sh_minpid; i < sh_maxpid; ++i)
285 {
286 fetch_socks(i);
287 }
288
289 return 0;
290}
291
292#include <sys/socket.h>
293#include <netinet/in.h>
294#include <arpa/inet.h>
295
296char * sh_port2proc_query(int proto, struct in_addr * saddr, int sport,
297 char * user, size_t userlen)
298{
299 FILE * fd;
300
301 if (proto == IPPROTO_TCP)
302 fd = fopen("/proc/net/tcp", "r");
303 else
304 fd = fopen("/proc/net/udp", "r");
305
306 if (fd)
307 {
308 int n, iface, port, inode;
309 char line[512];
310
311 while (NULL != fgets(line, sizeof(line), fd))
312 {
313
314 if (4 == sscanf(line,
315 "%d: %X:%X %*X:%*X %*X %*X:%*X %*X:%*X %*X %*d %*d %d %*s",
316 &n, &iface, &port, &inode))
317 {
318 struct in_addr haddr;
319 haddr.s_addr = (unsigned long)iface;
320
321 if (haddr.s_addr == saddr->s_addr && port == sport)
322 {
323 struct sock_store * new = socklist;
324
325 while (new)
326 {
327 if ((unsigned int)inode == new->sock)
328 {
329 fclose(fd);
330 if (new->path)
331 {
332 if (new->user)
333 sl_strlcpy(user, new->user, userlen);
334 else
335 sl_strlcpy(user, "-", userlen);
336 return sh_util_strdup(new->path);
337 }
338 goto err_out;
339 }
340 new = new->next;
341 }
342 }
343 }
344 }
345 fclose(fd);
346 }
347 err_out:
348 sl_strlcpy(user, "0", userlen);
349 return sh_util_strdup("-");
350}
351
352#else /* !defined(__linux__) */
353
354char * sh_port2proc_query(int proto, struct in_addr * saddr, int sport,
355 char * user, size_t userlen)
356{
357 (void) proto;
358 (void) saddr;
359 (void) sport;
360
361 sl_strlcpy(user, "-", userlen);
362 return sh_util_strdup("-");
363}
364
365int sh_port2proc_prepare()
366{
367 return 0;
368}
369
370#endif
371
372#endif /* defined(SH_USE_PORTCHECK) */
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