comparison libutil/gsm7_encode.c @ 6:86b4f288862d

libutil: functions for encoding MSISDN record
author Mychaela Falconia <falcon@freecalypso.org>
date Mon, 22 Feb 2021 00:41:12 +0000
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5:acb4d86e6ed7 6:86b4f288862d
1 /*
2 * This module implements functions for parsing quoted string
3 * arguments intended for GSM7 string encoding, and actually
4 * encoding them into GSM7 binary strings.
5 */
6
7 #include <sys/types.h>
8 #include <ctype.h>
9 #include <stdio.h>
10
11 extern u_char gsm7_encode_table[256];
12
13 qstring_arg_to_gsm7(arg, record, maxlen)
14 char *arg;
15 u_char *record;
16 unsigned maxlen;
17 {
18 unsigned acclen, nadd;
19 char *cp;
20 int c;
21
22 cp = arg;
23 for (acclen = 0; *cp; ) {
24 c = *cp++;
25 if (c == '\\') {
26 if (*cp == '\0') {
27 fprintf(stderr,
28 "error: dangling backslash escape\n");
29 return(-1);
30 }
31 c = *cp++;
32 if (c >= '0' && c <= '7' && isxdigit(*cp)) {
33 c = ((c - '0') << 4) | decode_hex_digit(*cp++);
34 goto bypass_encoding;
35 }
36 switch (c) {
37 case 'n':
38 c = '\n';
39 goto bypass_encoding;
40 case 'r':
41 c = '\r';
42 goto bypass_encoding;
43 case 'e':
44 c = 0x1B;
45 goto bypass_encoding;
46 case '"':
47 case '\\':
48 break;
49 default:
50 fprintf(stderr,
51 "error: non-understood backslash escape\n");
52 return(-1);
53 }
54 }
55 c = gsm7_encode_table[c];
56 if (c == 0xFF) {
57 fprintf(stderr,
58 "error: character in alpha tag string cannot be encoded in GSM7\n");
59 return(-1);
60 }
61 bypass_encoding:
62 if (c & 0x80)
63 nadd = 2;
64 else
65 nadd = 1;
66 if (acclen + nadd > maxlen) {
67 fprintf(stderr,
68 "error: alpha tag string is longer than SIM limit\n");
69 return(-1);
70 }
71 if (c & 0x80)
72 record[acclen++] = 0x1B;
73 record[acclen++] = c & 0x7F;
74 }
75 return(acclen);
76 }