added -y/--side-by-side option
[dfdiff.git] / usr.bin / truss / setup.c
blob4e6bc44dbeb18626536ba03605b7ddca14c92471
1 /*
2 * Copryight 1997 Sean Eric Fagan
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * 3. All advertising materials mentioning features or use of this software
13 * must display the following acknowledgement:
14 * This product includes software developed by Sean Eric Fagan
15 * 4. Neither the name of the author may be used to endorse or promote
16 * products derived from this software without specific prior written
17 * permission.
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
31 * $FreeBSD: src/usr.bin/truss/setup.c,v 1.10.2.2 2002/02/15 11:43:51 des Exp $
32 * $DragonFly: src/usr.bin/truss/setup.c,v 1.3 2003/11/04 15:34:41 eirikn Exp $
36 * Various setup functions for truss. Not the cleanest-written code,
37 * I'm afraid.
40 #include <sys/param.h>
41 #include <sys/ioctl.h>
42 #include <sys/pioctl.h>
43 #include <sys/wait.h>
45 #include <err.h>
46 #include <errno.h>
47 #include <fcntl.h>
48 #include <signal.h>
49 #include <stdio.h>
50 #include <stdlib.h>
51 #include <string.h>
52 #include <unistd.h>
54 #include "extern.h"
56 static int evflags = 0;
59 * setup_and_wait() is called to start a process. All it really does
60 * is fork(), set itself up to stop on exec or exit, and then exec
61 * the given command. At that point, the child process stops, and
62 * the parent can wake up and deal with it.
65 int
66 setup_and_wait(char *command[]) {
67 struct procfs_status pfs;
68 char *buf;
69 int fd;
70 int pid;
71 int flags;
73 pid = fork();
74 if (pid == -1) {
75 err(1, "fork failed");
77 if (pid == 0) { /* Child */
78 int mask = S_EXEC | S_EXIT;
79 asprintf(&buf, "%s/curproc/mem", procfs_path);
80 if (buf == NULL)
81 err(1, "Out of memory");
82 fd = open(buf, O_WRONLY);
83 free(buf);
84 if (fd == -1)
85 err(2, "cannot open %s", buf);
86 fcntl(fd, F_SETFD, 1);
87 if (ioctl(fd, PIOCBIS, mask) == -1)
88 err(3, "PIOCBIS");
89 flags = PF_LINGER;
91 * The PF_LINGER flag tells procfs not to wake up the
92 * process on last close; normally, this is the behaviour
93 * we want.
95 if (ioctl(fd, PIOCSFL, flags) == -1)
96 warn("cannot set PF_LINGER");
97 execvp(command[0], command);
98 mask = ~0;
99 ioctl(fd, PIOCBIC, ~0);
100 err(4, "execvp %s", command[0]);
102 /* Only in the parent here */
104 if (waitpid(pid, NULL, WNOHANG) != 0) {
106 * Process exited before it got to us -- meaning the exec failed
107 * miserably -- so we just quietly exit.
109 exit(1);
112 asprintf(&buf, "%s/%d/mem", procfs_path, pid);
113 if (buf == NULL)
114 err(1, "Out of memory");
115 fd = open(buf, O_RDWR);
116 free(buf);
117 if (fd == -1)
118 err(5, "cannot open %s", buf);
119 if (ioctl(fd, PIOCWAIT, &pfs) == -1)
120 err(6, "PIOCWAIT");
121 if (pfs.why == S_EXIT) {
122 fprintf(stderr, "process exited before exec'ing\n");
123 ioctl(fd, PIOCCONT, 0);
124 wait(0);
125 exit(7);
127 close(fd);
128 return pid;
132 * start_tracing picks up where setup_and_wait() dropped off -- namely,
133 * it sets the event mask for the given process id. Called for both
134 * monitoring an existing process and when we create our own.
138 start_tracing(int pid, int flags) {
139 int fd;
140 char *buf;
141 struct procfs_status tmp;
143 asprintf(&buf, "%s/%d/mem", procfs_path, pid);
144 if (buf == NULL)
145 err(1, "Out of memory");
146 fd = open(buf, O_RDWR);
147 free(buf);
148 if (fd == -1) {
150 * The process may have run away before we could start -- this
151 * happens with SUGID programs. So we need to see if it still
152 * exists before we complain bitterly.
154 if (kill(pid, 0) == -1)
155 return -1;
156 err(8, "cannot open %s", buf);
159 if (ioctl(fd, PIOCSTATUS, &tmp) == -1) {
160 err(10, "cannot get procfs status struct");
162 evflags = tmp.events;
164 if (ioctl(fd, PIOCBIS, flags) == -1)
165 err(9, "cannot set procfs event bit mask");
168 * This clears the PF_LINGER set above in setup_and_wait();
169 * if truss happens to die before this, then the process
170 * needs to be woken up via procctl.
173 if (ioctl(fd, PIOCSFL, 0) == -1)
174 warn("cannot clear PF_LINGER");
176 return fd;
180 * Restore a process back to it's pre-truss state.
181 * Called for SIGINT, SIGTERM, SIGQUIT. This only
182 * applies if truss was told to monitor an already-existing
183 * process.
185 void
186 restore_proc(int signo __unused) {
187 extern int Procfd;
189 ioctl(Procfd, PIOCBIC, ~0);
190 if (evflags)
191 ioctl(Procfd, PIOCBIS, evflags);
192 exit(0);