1 /*
2  * SPDX-License-Identifier: ISC
3  *
4  * Copyright (c) 2007, 2013-2016 Todd C. Miller <Todd.Miller@sudo.ws>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 /*
20  * This is an open source non-commercial project. Dear PVS-Studio, please check it.
21  * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
22  */
23 
24 #include <config.h>
25 
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <ctype.h>
30 #ifdef HAVE_STDBOOL_H
31 # include <stdbool.h>
32 #else
33 # include "compat/stdbool.h"
34 #endif
35 
36 #include "sudo_compat.h"
37 #include "sudo_util.h"
38 #include "sudo_debug.h"
39 
40 /*
41  * Read a line of input, honoring line continuation chars.
42  * Remove comments and strip off leading and trailing spaces.
43  * Returns the line length and updates the buf and bufsize pointers.
44  * XXX - just use a struct w/ state, including getdelim buffer?
45  *       could also make comment char and line continuation configurable
46  */
47 ssize_t
sudo_parseln_v2(char ** bufp,size_t * bufsizep,unsigned int * lineno,FILE * fp,int flags)48 sudo_parseln_v2(char **bufp, size_t *bufsizep, unsigned int *lineno, FILE *fp, int flags)
49 {
50     size_t linesize = 0, total = 0;
51     ssize_t len;
52     char *cp, *line = NULL;
53     bool continued, comment;
54     debug_decl(sudo_parseln, SUDO_DEBUG_UTIL);
55 
56     do {
57 	comment = false;
58 	continued = false;
59 	len = getdelim(&line, &linesize, '\n', fp);
60 	if (len == -1)
61 	    break;
62 	if (lineno != NULL)
63 	    (*lineno)++;
64 
65 	/* Remove trailing newline(s) if present. */
66 	while (len > 0 && (line[len - 1] == '\n' || line[len - 1] == '\r'))
67 	    line[--len] = '\0';
68 
69 	/* Remove comments or check for line continuation (but not both) */
70 	if ((cp = strchr(line, '#')) != NULL) {
71 	    if (cp == line || !ISSET(flags, PARSELN_COMM_BOL)) {
72 		*cp = '\0';
73 		len = (ssize_t)(cp - line);
74 		comment = true;
75 	    }
76 	}
77 	if (!comment && !ISSET(flags, PARSELN_CONT_IGN)) {
78 	    if (len > 0 && line[len - 1] == '\\' && (len == 1 || line[len - 2] != '\\')) {
79 		line[--len] = '\0';
80 		continued = true;
81 	    }
82 	}
83 
84 	/* Trim leading and trailing whitespace */
85 	if (!continued) {
86 	    while (len > 0 && isblank((unsigned char)line[len - 1]))
87 		line[--len] = '\0';
88 	}
89 	for (cp = line; isblank((unsigned char)*cp); cp++)
90 	    len--;
91 
92 	if (*bufp == NULL || total + len >= *bufsizep) {
93 	    void *tmp;
94 	    size_t size = total + len + 1;
95 
96 	    if (size < 64) {
97 		size = 64;
98 	    } else if (size <= 0x80000000) {
99 		/* Round up to next highest power of two. */
100 		size--;
101 		size |= size >> 1;
102 		size |= size >> 2;
103 		size |= size >> 4;
104 		size |= size >> 8;
105 		size |= size >> 16;
106 		size++;
107 	    }
108 	    if ((tmp = realloc(*bufp, size)) == NULL) {
109 		sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
110 		    "unable to allocate memory");
111 		len = -1;
112 		total = 0;
113 		break;
114 	    }
115 	    *bufp = tmp;
116 	    *bufsizep = size;
117 	}
118 	memcpy(*bufp + total, cp, len + 1);
119 	total += len;
120     } while (continued);
121     free(line);
122     if (len == -1 && total == 0)
123 	debug_return_ssize_t(-1);
124     debug_return_ssize_t(total);
125 }
126 
127 ssize_t
sudo_parseln_v1(char ** bufp,size_t * bufsizep,unsigned int * lineno,FILE * fp)128 sudo_parseln_v1(char **bufp, size_t *bufsizep, unsigned int *lineno, FILE *fp)
129 {
130     return sudo_parseln_v2(bufp, bufsizep, lineno, fp, 0);
131 }
132