1/*
2 * kmod-remove - remove modules from the kernel.
3 *
4 * Copyright (C) 2015 Intel Corporation. All rights reserved.
5 * Copyright (C) 2011-2013  ProFUSION embedded systems
6 *
7 * This program is free software: you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
19 */
20
21#include <errno.h>
22#include <getopt.h>
23#include <stdlib.h>
24#include <string.h>
25
26#include <libkmod/libkmod.h>
27
28#include "kmod.h"
29
30static const char cmdopts_s[] = "h";
31static const struct option cmdopts[] = {
32	{"help", no_argument, 0, 'h'},
33	{ }
34};
35
36static void help(void)
37{
38	printf("Usage:\n"
39	       "\t%s remove [options] module\n"
40	       "Options:\n"
41	       "\t-h, --help        show this help\n",
42	       program_invocation_short_name);
43}
44
45static int check_module_inuse(struct kmod_module *mod) {
46	struct kmod_list *holders;
47	int state;
48
49	state = kmod_module_get_initstate(mod);
50
51	if (state == KMOD_MODULE_BUILTIN) {
52		ERR("Module %s is builtin.\n", kmod_module_get_name(mod));
53		return -ENOENT;
54	} else if (state < 0) {
55		ERR("Module %s is not currently loaded\n",
56				kmod_module_get_name(mod));
57		return -ENOENT;
58	}
59
60	holders = kmod_module_get_holders(mod);
61	if (holders != NULL) {
62		struct kmod_list *itr;
63
64		ERR("Module %s is in use by:", kmod_module_get_name(mod));
65
66		kmod_list_foreach(itr, holders) {
67			struct kmod_module *hm = kmod_module_get_module(itr);
68			fprintf(stderr, " %s", kmod_module_get_name(hm));
69			kmod_module_unref(hm);
70		}
71		fputc('\n', stderr);
72
73		kmod_module_unref_list(holders);
74		return -EBUSY;
75	}
76
77	if (kmod_module_get_refcnt(mod) != 0) {
78		ERR("Module %s is in use\n", kmod_module_get_name(mod));
79		return -EBUSY;
80	}
81
82	return 0;
83}
84
85static int do_remove(int argc, char *argv[])
86{
87	struct kmod_ctx *ctx;
88	struct kmod_module *mod;
89	const char *name;
90	int err, r = EXIT_SUCCESS;
91
92	for (;;) {
93		int c, idx =0;
94		c = getopt_long(argc, argv, cmdopts_s, cmdopts, &idx);
95		if (c == -1)
96			break;
97		switch (c) {
98		case 'h':
99			help();
100			return EXIT_SUCCESS;
101
102		default:
103			ERR("Unexpected getopt_long() value '%c'.\n", c);
104			return EXIT_FAILURE;
105		}
106	}
107
108	if (optind >= argc) {
109		ERR("Missing module name\n");
110		return EXIT_FAILURE;
111	}
112
113	ctx = kmod_new(NULL, NULL);
114	if (!ctx) {
115		ERR("kmod_new() failed!\n");
116		return EXIT_FAILURE;
117	}
118
119	name = argv[optind];
120	err = kmod_module_new_from_name(ctx, name, &mod);
121	if (err < 0) {
122		ERR("Could not remove module %s: %s\n", name, strerror(-err));
123		goto end;
124	}
125
126	err = check_module_inuse(mod);
127	if (err < 0)
128		goto unref;
129
130	err = kmod_module_remove_module(mod, 0);
131	if (err < 0)
132		goto unref;
133
134unref:
135	kmod_module_unref(mod);
136
137end:
138	kmod_unref(ctx);
139	if (err < 0) {
140		r = EXIT_FAILURE;
141		ERR("Could not remove module %s: %s\n", name, strerror(-err));
142	}
143	return r;
144}
145
146const struct kmod_cmd kmod_cmd_remove = {
147	.name = "remove",
148	.cmd = do_remove,
149	.help = "remove module from kernel",
150};
151