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