xref: /illumos-gate/usr/src/lib/libcmdutils/common/writefile.c (revision 3ba944265c4ae1fcf23ef758537c2e4f4feec16e)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 /*
31  * University Copyright- Copyright (c) 1982, 1986, 1988
32  * The Regents of the University of California
33  * All Rights Reserved
34  *
35  * University Acknowledgment- Portions of this document are derived from
36  * software developed by the University of California, Berkeley, and its
37  * contributors.
38  */
39 
40 #include "libcmdutils.h"
41 
42 
43 int
44 writefile(int fi, int fo, char *infile, char *outfile, char *asfile,
45     char *atfile, struct stat *s1p, struct stat *s2p)
46 {
47 	int mapsize, munmapsize;
48 	caddr_t cp;
49 	off_t filesize = s1p->st_size;
50 	off_t offset;
51 	int nbytes;
52 	int remains;
53 	int n;
54 	size_t src_size;
55 	size_t targ_size;
56 	char *srcbuf;
57 	char *targbuf;
58 
59 	if (asfile != NULL) {
60 		src_size = strlen(infile) + strlen(asfile) +
61 		    strlen(dgettext(TEXT_DOMAIN, " attribute ")) + 1;
62 	} else {
63 		src_size = strlen(infile) + 1;
64 	}
65 	srcbuf = malloc(src_size);
66 	if (srcbuf == NULL) {
67 		(void) fprintf(stderr,
68 		    dgettext(TEXT_DOMAIN, "could not allocate memory"
69 		    " for path buffer: "));
70 		return (1);
71 	}
72 	if (asfile != NULL) {
73 		(void) snprintf(srcbuf, src_size, "%s%s%s",
74 		    infile, dgettext(TEXT_DOMAIN, " attribute "), asfile);
75 	} else {
76 		(void) snprintf(srcbuf, src_size, "%s", infile);
77 	}
78 
79 	if (atfile != NULL) {
80 		targ_size = strlen(outfile) + strlen(atfile) +
81 		    strlen(dgettext(TEXT_DOMAIN, " attribute ")) + 1;
82 	} else {
83 		targ_size = strlen(outfile) + 1;
84 	}
85 	targbuf = malloc(targ_size);
86 	if (targbuf == NULL) {
87 		(void) fprintf(stderr,
88 		    dgettext(TEXT_DOMAIN, "could not allocate memory"
89 		    " for path buffer: "));
90 		return (1);
91 	}
92 	if (atfile != NULL) {
93 		(void) snprintf(targbuf, targ_size, "%s%s%s",
94 		    outfile, dgettext(TEXT_DOMAIN, " attribute "), atfile);
95 	} else {
96 		(void) snprintf(targbuf, targ_size, "%s", outfile);
97 	}
98 
99 	if (S_ISREG(s1p->st_mode) && s1p->st_size > SMALLFILESIZE) {
100 		/*
101 		 * Determine size of initial mapping.  This will determine the
102 		 * size of the address space chunk we work with.  This initial
103 		 * mapping size will be used to perform munmap() in the future.
104 		 */
105 		mapsize = MAXMAPSIZE;
106 		if (s1p->st_size < mapsize) mapsize = s1p->st_size;
107 		munmapsize = mapsize;
108 
109 		/*
110 		 * Mmap time!
111 		 */
112 		if ((cp = mmap((caddr_t)NULL, mapsize, PROT_READ,
113 		    MAP_SHARED, fi, (off_t)0)) == MAP_FAILED)
114 			mapsize = 0;   /* can't mmap today */
115 	} else
116 		mapsize = 0;
117 
118 	if (mapsize != 0) {
119 		offset = 0;
120 
121 		for (;;) {
122 			nbytes = write(fo, cp, mapsize);
123 			/*
124 			 * if we write less than the mmaped size it's due to a
125 			 * media error on the input file or out of space on
126 			 * the output file.  So, try again, and look for errno.
127 			 */
128 			if ((nbytes >= 0) && (nbytes != (int)mapsize)) {
129 				remains = mapsize - nbytes;
130 				while (remains > 0) {
131 					nbytes = write(fo,
132 					    cp + mapsize - remains, remains);
133 					if (nbytes < 0) {
134 						if (errno == ENOSPC)
135 							perror(targbuf);
136 						else
137 							perror(srcbuf);
138 						(void) close(fi);
139 						(void) close(fo);
140 						(void) munmap(cp, munmapsize);
141 						if (S_ISREG(s2p->st_mode))
142 							(void) unlink(targbuf);
143 						return (1);
144 					}
145 					remains -= nbytes;
146 					if (remains == 0)
147 						nbytes = mapsize;
148 				}
149 			}
150 			/*
151 			 * although the write manual page doesn't specify this
152 			 * as a possible errno, it is set when the nfs read
153 			 * via the mmap'ed file is accessed, so report the
154 			 * problem as a source access problem, not a target file
155 			 * problem
156 			 */
157 			if (nbytes < 0) {
158 				if (errno == EACCES)
159 					perror(srcbuf);
160 				else
161 					perror(targbuf);
162 				(void) close(fi);
163 				(void) close(fo);
164 				(void) munmap(cp, munmapsize);
165 				if (S_ISREG(s2p->st_mode))
166 					(void) unlink(targbuf);
167 				if (srcbuf != NULL)
168 					free(srcbuf);
169 				if (targbuf != NULL)
170 					free(targbuf);
171 				return (1);
172 			}
173 			filesize -= nbytes;
174 			if (filesize == 0)
175 				break;
176 			offset += nbytes;
177 			if (filesize < mapsize)
178 				mapsize = filesize;
179 			if (mmap(cp, mapsize, PROT_READ, MAP_SHARED |
180 			    MAP_FIXED, fi, offset) == MAP_FAILED) {
181 				perror(srcbuf);
182 				(void) close(fi);
183 				(void) close(fo);
184 				(void) munmap(cp, munmapsize);
185 				if (S_ISREG(s2p->st_mode))
186 					(void) unlink(targbuf);
187 				if (srcbuf != NULL)
188 					free(srcbuf);
189 				if (targbuf != NULL)
190 					free(targbuf);
191 				return (1);
192 			}
193 		}
194 		(void) munmap(cp, munmapsize);
195 	} else {
196 		char buf[SMALLFILESIZE];
197 		for (;;) {
198 			n = read(fi, buf, sizeof (buf));
199 			if (n == 0) {
200 				return (0);
201 			} else if (n < 0) {
202 				(void) close(fi);
203 				(void) close(fo);
204 				if (S_ISREG(s2p->st_mode))
205 					(void) unlink(targbuf);
206 				if (srcbuf != NULL)
207 					free(srcbuf);
208 				if (targbuf != NULL)
209 					free(targbuf);
210 				return (1);
211 			} else if (write(fo, buf, n) != n) {
212 				(void) close(fi);
213 				(void) close(fo);
214 				if (S_ISREG(s2p->st_mode))
215 					(void) unlink(targbuf);
216 				if (srcbuf != NULL)
217 					free(srcbuf);
218 				if (targbuf != NULL)
219 					free(targbuf);
220 				return (1);
221 			}
222 		}
223 	}
224 	if (srcbuf != NULL)
225 		free(srcbuf);
226 	if (targbuf != NULL)
227 		free(targbuf);
228 	return (0);
229 }
230