1 /*
2 * This file contains helper functions for labeling support.
3 *
4 * Author : Richard Haines <richard_c_haines@btinternet.com>
5 */
6
7 #include <stdlib.h>
8 #include <stdarg.h>
9 #include <ctype.h>
10 #include <string.h>
11 #include <stdio.h>
12 #include <errno.h>
13 #include "label_internal.h"
14
15 /*
16 * The read_spec_entries and read_spec_entry functions may be used to
17 * replace sscanf to read entries from spec files. The file and
18 * property services now use these.
19 */
read_spec_entry(char ** entry,char ** ptr,int * len)20 static inline int read_spec_entry(char **entry, char **ptr, int *len)
21 {
22 *entry = NULL;
23 char *tmp_buf = NULL;
24
25 while (isspace(**ptr) && **ptr != '\0')
26 (*ptr)++;
27
28 tmp_buf = *ptr;
29 *len = 0;
30
31 while (!isspace(**ptr) && **ptr != '\0') {
32 (*ptr)++;
33 (*len)++;
34 }
35
36 if (*len) {
37 *entry = strndup(tmp_buf, *len);
38 if (!*entry)
39 return -1;
40 }
41
42 return 0;
43 }
44
45 /*
46 * line_buf - Buffer containing the spec entries .
47 * num_args - The number of spec parameter entries to process.
48 * ... - A 'char **spec_entry' for each parameter.
49 * returns - The number of items processed.
50 *
51 * This function calls read_spec_entry() to do the actual string processing.
52 */
read_spec_entries(char * line_buf,int num_args,...)53 int hidden read_spec_entries(char *line_buf, int num_args, ...)
54 {
55 char **spec_entry, *buf_p;
56 int len, rc, items, entry_len = 0;
57 va_list ap;
58
59 len = strlen(line_buf);
60 if (line_buf[len - 1] == '\n')
61 line_buf[len - 1] = '\0';
62 else
63 /* Handle case if line not \n terminated by bumping
64 * the len for the check below (as the line is NUL
65 * terminated by getline(3)) */
66 len++;
67
68 buf_p = line_buf;
69 while (isspace(*buf_p))
70 buf_p++;
71
72 /* Skip comment lines and empty lines. */
73 if (*buf_p == '#' || *buf_p == '\0')
74 return 0;
75
76 /* Process the spec file entries */
77 va_start(ap, num_args);
78
79 items = 0;
80 while (items < num_args) {
81 spec_entry = va_arg(ap, char **);
82
83 if (len - 1 == buf_p - line_buf) {
84 va_end(ap);
85 return items;
86 }
87
88 rc = read_spec_entry(spec_entry, &buf_p, &entry_len);
89 if (rc < 0) {
90 va_end(ap);
91 return rc;
92 }
93 if (entry_len)
94 items++;
95 }
96 va_end(ap);
97 return items;
98 }
99
100 /* Once all the specfiles are in the hash_buf, generate the hash. */
digest_gen_hash(struct selabel_digest * digest)101 void hidden digest_gen_hash(struct selabel_digest *digest)
102 {
103 Sha1Context context;
104
105 /* If SELABEL_OPT_DIGEST not set then just return */
106 if (!digest)
107 return;
108
109 Sha1Initialise(&context);
110 Sha1Update(&context, digest->hashbuf, digest->hashbuf_size);
111 Sha1Finalise(&context, (SHA1_HASH *)digest->digest);
112 free(digest->hashbuf);
113 digest->hashbuf = NULL;
114 return;
115 }
116
117 /**
118 * digest_add_specfile - Add a specfile to the hashbuf and if gen_hash true
119 * then generate the hash.
120 * @digest: pointer to the selabel_digest struct
121 * @fp: file pointer for fread(3) or NULL if not.
122 * @from_addr: pointer at start of buffer for memcpy or NULL if not (used for
123 * mmap(3) files).
124 * @buf_len: length of buffer to copy.
125 * @path: pointer to the specfile.
126 *
127 * Return %0 on success, -%1 with @errno set on failure.
128 */
digest_add_specfile(struct selabel_digest * digest,FILE * fp,char * from_addr,size_t buf_len,const char * path)129 int hidden digest_add_specfile(struct selabel_digest *digest, FILE *fp,
130 char *from_addr, size_t buf_len,
131 const char *path)
132 {
133 unsigned char *tmp_buf;
134
135 /* If SELABEL_OPT_DIGEST not set then just return */
136 if (!digest)
137 return 0;
138
139 if (digest->hashbuf_size + buf_len < digest->hashbuf_size) {
140 errno = EOVERFLOW;
141 return -1;
142 }
143 digest->hashbuf_size += buf_len;
144
145 tmp_buf = realloc(digest->hashbuf, digest->hashbuf_size);
146 if (!tmp_buf)
147 return -1;
148
149 digest->hashbuf = tmp_buf;
150
151 if (fp) {
152 rewind(fp);
153 if (fread(digest->hashbuf + (digest->hashbuf_size - buf_len),
154 1, buf_len, fp) != buf_len)
155 return -1;
156
157 rewind(fp);
158 } else if (from_addr) {
159 tmp_buf = memcpy(digest->hashbuf +
160 (digest->hashbuf_size - buf_len),
161 from_addr, buf_len);
162 if (!tmp_buf)
163 return -1;
164 }
165 /* Now add path to list */
166 digest->specfile_list[digest->specfile_cnt] = strdup(path);
167 if (!digest->specfile_list[digest->specfile_cnt])
168 return -1;
169
170 digest->specfile_cnt++;
171 if (digest->specfile_cnt > DIGEST_FILES_MAX) {
172 errno = EOVERFLOW;
173 return -1;
174 }
175
176 return 0;
177 }
178