1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1992, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
30 */
31
32/*
33 * Originally written by Eric Cooper in Fall 1981.
34 * Inspired by a version 6 program by Len Levin, 1978.
35 * Several pieces of code lifted from Bill Joy's 4BSD ps.
36 * Most recently, hacked beyond recognition for 4.4BSD by Steven McCanne,
37 * Lawrence Berkeley Laboratory.
38 *
39 * Portions of this software were developed by the Computer Systems
40 * Engineering group at Lawrence Berkeley Laboratory under DARPA
41 * contract BG 91-66 and contributed to Berkeley.
42 */
43
44#include <sys/param.h>
45#include <sys/ptrace.h>
46#include <sys/time.h>
47#include <sys/stat.h>
48#include <sys/linker_set.h>
49#include <sys/sysctl.h>
50#include <sys/wait.h>
51
52#include <err.h>
53#include <fcntl.h>
54#include <stdbool.h>
55#include <stdio.h>
56#include <stdlib.h>
57#include <string.h>
58#include <unistd.h>
59
60#include "extern.h"
61int pflags;
62
63static void	killed(int);
64static void	usage(void) __dead2;
65
66static pid_t pid;
67static bool kflag = false;
68
69SET_DECLARE(dumpset, struct dumpers);
70
71static int
72open_corefile(char *corefile)
73{
74	char fname[MAXPATHLEN];
75	int fd;
76
77	if (corefile == NULL) {
78		(void)snprintf(fname, sizeof(fname), "core.%d", pid);
79		corefile = fname;
80	}
81	fd = open(corefile, O_RDWR | O_CREAT | O_TRUNC, DEFFILEMODE);
82	if (fd < 0)
83		err(1, "%s", corefile);
84	return (fd);
85}
86
87static void
88kcoredump(int fd, pid_t pid)
89{
90	struct ptrace_coredump pc;
91	int error, res, ret, waited;
92
93	error = ptrace(PT_ATTACH, pid, NULL, 0);
94	if (error != 0)
95		err(1, "attach");
96
97	waited = waitpid(pid, &res, 0);
98	if (waited == -1)
99		err(1, "wait for STOP");
100
101	ret = 0;
102	memset(&pc, 0, sizeof(pc));
103	pc.pc_fd = fd;
104	pc.pc_flags = (pflags & PFLAGS_FULL) != 0 ? PC_ALL : 0;
105	error = ptrace(PT_COREDUMP, pid, (void *)&pc, sizeof(pc));
106	if (error == -1) {
107		warn("coredump");
108		ret = 1;
109	}
110
111	waited = waitpid(pid, &res, WNOHANG);
112	if (waited == -1) {
113		warn("wait after coredump");
114		ret = 1;
115	}
116
117	error = ptrace(PT_DETACH, pid, NULL, 0);
118	if (error == -1) {
119		warn("detach failed, check process status");
120		ret = 1;
121	}
122
123	exit(ret);
124}
125
126int
127main(int argc, char *argv[])
128{
129	int ch, efd, fd, name[4];
130	char *binfile, *corefile;
131	char passpath[MAXPATHLEN];
132	struct dumpers **d, *dumper;
133	size_t len;
134
135	pflags = 0;
136	corefile = NULL;
137        while ((ch = getopt(argc, argv, "c:fk")) != -1) {
138                switch (ch) {
139                case 'c':
140			corefile = optarg;
141                        break;
142		case 'f':
143			pflags |= PFLAGS_FULL;
144			break;
145		case 'k':
146			kflag = true;
147			break;
148		default:
149			usage();
150			break;
151		}
152	}
153	argv += optind;
154	argc -= optind;
155
156	/* XXX we should check that the pid argument is really a number */
157	switch (argc) {
158	case 1:
159		pid = atoi(argv[0]);
160		break;
161	case 2:
162		binfile = argv[0];
163		pid = atoi(argv[1]);
164		break;
165	default:
166		usage();
167	}
168
169	if (kflag) {
170		fd = open_corefile(corefile);
171		kcoredump(fd, pid);
172	}
173
174	if (argc == 1) {
175		name[0] = CTL_KERN;
176		name[1] = KERN_PROC;
177		name[2] = KERN_PROC_PATHNAME;
178		name[3] = pid;
179		len = sizeof(passpath);
180		if (sysctl(name, 4, passpath, &len, NULL, 0) == -1)
181			errx(1, "kern.proc.pathname failure");
182		binfile = passpath;
183	}
184	efd = open(binfile, O_RDONLY, 0);
185	if (efd < 0)
186		err(1, "%s", binfile);
187	dumper = NULL;
188	SET_FOREACH(d, dumpset) {
189		lseek(efd, 0, SEEK_SET);
190		if (((*d)->ident)(efd, pid, binfile)) {
191			dumper = (*d);
192			lseek(efd, 0, SEEK_SET);
193			break;
194		}
195	}
196	if (dumper == NULL)
197		errx(1, "Invalid executable file");
198	fd = open_corefile(corefile);
199
200	dumper->dump(efd, fd, pid);
201	(void)close(fd);
202	(void)close(efd);
203	exit(0);
204}
205
206void
207usage(void)
208{
209
210	(void)fprintf(stderr,
211	    "usage: gcore [-kf] [-c core] [executable] pid\n");
212	exit(1);
213}
214