xref: /freebsd/stand/common/misc.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /*-
2  * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
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
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 #include <string.h>
29 #include <stand.h>
30 #include <bootstrap.h>
31 
32 /*
33  * Concatenate the (argc) elements of (argv) into a single string, and return
34  * a copy of same.
35  */
36 char *
37 unargv(int argc, char *argv[])
38 {
39     size_t	hlong;
40     int		i;
41     char	*cp;
42 
43     for (i = 0, hlong = 0; i < argc; i++)
44 	hlong += strlen(argv[i]) + 2;
45 
46     if(hlong == 0)
47 	return(NULL);
48 
49     cp = malloc(hlong);
50     cp[0] = 0;
51     for (i = 0; i < argc; i++) {
52 	strcat(cp, argv[i]);
53 	if (i < (argc - 1))
54 	  strcat(cp, " ");
55     }
56 
57     return(cp);
58 }
59 
60 /*
61  * Get the length of a string in kernel space
62  */
63 size_t
64 strlenout(vm_offset_t src)
65 {
66     char	c;
67     size_t	len;
68 
69     for (len = 0; ; len++) {
70 	archsw.arch_copyout(src++, &c, 1);
71 	if (c == 0)
72 	    break;
73     }
74     return(len);
75 }
76 
77 /*
78  * Make a duplicate copy of a string in kernel space
79  */
80 char *
81 strdupout(vm_offset_t str)
82 {
83     char	*result, *cp;
84 
85     result = malloc(strlenout(str) + 1);
86     for (cp = result; ;cp++) {
87 	archsw.arch_copyout(str++, cp, 1);
88 	if (*cp == 0)
89 	    break;
90     }
91     return(result);
92 }
93 
94 /* Zero a region in kernel space. */
95 void
96 kern_bzero(vm_offset_t dest, size_t len)
97 {
98 	char buf[256];
99 	size_t chunk, resid;
100 
101 	bzero(buf, sizeof(buf));
102 	resid = len;
103 	while (resid > 0) {
104 		chunk = min(sizeof(buf), resid);
105 		archsw.arch_copyin(buf, dest, chunk);
106 		resid -= chunk;
107 		dest += chunk;
108 	}
109 }
110 
111 /*
112  * Read the specified part of a file to kernel space.  Unlike regular
113  * pread, the file pointer is advanced to the end of the read data,
114  * and it just returns 0 if successful.
115  */
116 int
117 kern_pread(readin_handle_t fd, vm_offset_t dest, size_t len, off_t off)
118 {
119 
120 	if (VECTX_LSEEK(fd, off, SEEK_SET) == -1) {
121 #ifdef DEBUG
122 		printf("\nlseek failed\n");
123 #endif
124 		return (-1);
125 	}
126 	if ((size_t)archsw.arch_readin(fd, dest, len) != len) {
127 #ifdef DEBUG
128 		printf("\nreadin failed\n");
129 #endif
130 		return (-1);
131 	}
132 	return (0);
133 }
134 
135 /*
136  * Read the specified part of a file to a malloced buffer.  The file
137  * pointer is advanced to the end of the read data.
138  */
139 /* coverity[ -tainted_data_return ] */
140 void *
141 alloc_pread(readin_handle_t fd, off_t off, size_t len)
142 {
143 	void *buf;
144 
145 	buf = malloc(len);
146 	if (buf == NULL) {
147 #ifdef DEBUG
148 		printf("\nmalloc(%d) failed\n", (int)len);
149 #endif
150 		errno = ENOMEM;
151 		return (NULL);
152 	}
153 	if (VECTX_LSEEK(fd, off, SEEK_SET) == -1) {
154 #ifdef DEBUG
155 		printf("\nlseek failed\n");
156 #endif
157 		free(buf);
158 		return (NULL);
159 	}
160 	if ((size_t)VECTX_READ(fd, buf, len) != len) {
161 #ifdef DEBUG
162 		printf("\nread failed\n");
163 #endif
164 		free(buf);
165 		return (NULL);
166 	}
167 	return (buf);
168 }
169 
170 /*
171  * mount new rootfs and unmount old, set "currdev" environment variable.
172  */
173 int mount_currdev(struct env_var *ev, int flags, const void *value)
174 {
175 	int rv;
176 
177 	/* mount new rootfs */
178 	rv = mount(value, "/", 0, NULL);
179 	if (rv == 0) {
180 		/*
181 		 * Note we unmount any previously mounted fs only after
182 		 * successfully mounting the new because we do not want to
183 		 * end up with unmounted rootfs.
184 		 */
185 		if (ev->ev_value != NULL)
186 			unmount(ev->ev_value, 0);
187 		env_setenv(ev->ev_name, flags | EV_NOHOOK, value, NULL, NULL);
188 	}
189 	return (rv);
190 }
191 
192 /*
193  * Set currdev to suit the value being supplied in (value)
194  */
195 int
196 gen_setcurrdev(struct env_var *ev, int flags, const void *value)
197 {
198 	struct devdesc *ncurr;
199 	int rv;
200 
201 	if ((rv = devparse(&ncurr, value, NULL)) != 0)
202 		return (rv);
203 	free(ncurr);
204 
205 	return (mount_currdev(ev, flags, value));
206 }
207 
208 /*
209  * Wrapper to set currdev and loaddev at the same time.
210  */
211 void
212 set_currdev(const char *devname)
213 {
214 
215 	env_setenv("currdev", EV_VOLATILE, devname, gen_setcurrdev,
216 	    env_nounset);
217 	/*
218 	 * Don't execute hook here; the loaddev hook makes it immutable
219 	 * once we've determined what the proper currdev is.
220 	 */
221 	env_setenv("loaddev", EV_VOLATILE | EV_NOHOOK, devname, env_noset,
222 	    env_nounset);
223 }
224