1 #include <errno.h>
2 #include <string.h>
3 #include <sys/types.h>
4 #include <netinet/in.h>
5
6 #include "utils.h"
7
dn_ntohs(u_int16_t addr)8 static __inline__ u_int16_t dn_ntohs(u_int16_t addr)
9 {
10 union {
11 u_int8_t byte[2];
12 u_int16_t word;
13 } u;
14
15 u.word = addr;
16 return ((u_int16_t)u.byte[0]) | (((u_int16_t)u.byte[1]) << 8);
17 }
18
do_digit(char * str,u_int16_t * addr,u_int16_t scale,size_t * pos,size_t len,int * started)19 static __inline__ int do_digit(char *str, u_int16_t *addr, u_int16_t scale, size_t *pos, size_t len, int *started)
20 {
21 u_int16_t tmp = *addr / scale;
22
23 if (*pos == len)
24 return 1;
25
26 if (((tmp) > 0) || *started || (scale == 1)) {
27 *str = tmp + '0';
28 *started = 1;
29 (*pos)++;
30 *addr -= (tmp * scale);
31 }
32
33 return 0;
34 }
35
36
dnet_ntop1(const struct dn_naddr * dna,char * str,size_t len)37 static const char *dnet_ntop1(const struct dn_naddr *dna, char *str, size_t len)
38 {
39 u_int16_t addr, area;
40 size_t pos = 0;
41 int started = 0;
42
43 memcpy(&addr, dna->a_addr, sizeof(addr));
44 addr = dn_ntohs(addr);
45 area = addr >> 10;
46
47 if (dna->a_len != 2)
48 return NULL;
49
50 addr &= 0x03ff;
51
52 if (len == 0)
53 return str;
54
55 if (do_digit(str + pos, &area, 10, &pos, len, &started))
56 return str;
57
58 if (do_digit(str + pos, &area, 1, &pos, len, &started))
59 return str;
60
61 if (pos == len)
62 return str;
63
64 *(str + pos) = '.';
65 pos++;
66 started = 0;
67
68 if (do_digit(str + pos, &addr, 1000, &pos, len, &started))
69 return str;
70
71 if (do_digit(str + pos, &addr, 100, &pos, len, &started))
72 return str;
73
74 if (do_digit(str + pos, &addr, 10, &pos, len, &started))
75 return str;
76
77 if (do_digit(str + pos, &addr, 1, &pos, len, &started))
78 return str;
79
80 if (pos == len)
81 return str;
82
83 *(str + pos) = 0;
84
85 return str;
86 }
87
88
dnet_ntop(int af,const void * addr,char * str,size_t len)89 const char *dnet_ntop(int af, const void *addr, char *str, size_t len)
90 {
91 switch(af) {
92 case AF_DECnet:
93 errno = 0;
94 return dnet_ntop1((struct dn_naddr *)addr, str, len);
95 default:
96 errno = EAFNOSUPPORT;
97 }
98
99 return NULL;
100 }
101