1IPSEC_ATOASR(3) Library Functions Manual IPSEC_ATOASR(3)
2
6 ipsec atoasr - convert ASCII to Internet address, subnet, or range
7 ipsec rangetoa - convert Internet address range to ASCII
8
10 #include <freeswan.h>
11 const char *atoasr(const char *src, size_t srclen,
13 char *type, struct in_addr *addrs);
14 size_t rangetoa(struct in_addr *addrs, int format,
15 char *dst, size_t dstlen);
16
18 These functions are obsolete; there is no current equivalent, because
19 so far they have not proved useful.
20 Atoasr converts an ASCII address, subnet, or address range into a suit‐
22 able combination of binary addresses (in network byte order). Rangetoa
23 converts an address range back into ASCII, using dotted-decimal form
24 for the addresses (the other reverse conversions are handled by
25 ipsec_addrtoa(3) and ipsec_subnettoa(3)).
26 A single address can be any form acceptable to ipsec_atoaddr(3): dotted
28 decimal, DNS name, or hexadecimal number. A subnet specification uses
29 the form network/mask interpreted by ipsec_atosubnet(3).
30 An address range is two ipsec_atoaddr(3) addresses separated by a ...
32 delimiter. If there are four dots rather than three, the first is
33 taken as part of the begin address, e.g. for a complete DNS name which
34 ends with . to suppress completion attempts. The begin address of a
35 range must be less than or equal to the end address.
36 The srclen parameter of atoasr specifies the length of the ASCII string
38 pointed to by src; it is an error for there to be anything else (e.g.,
39 a terminating NUL) within that length. As a convenience for cases
40 where an entire NUL-terminated string is to be converted, a srclen
41 value of 0 is taken to mean strlen(src).
42 The type parameter of atoasr must point to a char variable used to
44 record which form was found. The addrs parameter must point to a two-
45 element array of struct in_addr which receives the results. The values
46 stored into *type, and the corresponding values in the array, are:
47 *type addrs[0] addrs[1]
49 address 'a' address -
51 subnet 's' network mask
52 range 'r' begin end
53 The dstlen parameter of rangetoa specifies the size of the dst parame‐
55 ter; under no circumstances are more than dstlen bytes written to dst.
56 A result which will not fit is truncated. Dstlen can be zero, in which
57 case dst need not be valid and no result is written, but the return
58 value is unaffected; in all other cases, the (possibly truncated)
59 result is NUL-terminated. The freeswan.h header file defines a con‐
60 stant, RANGETOA_BUF, which is the size of a buffer just large enough
61 for worst-case results.
62 The format parameter of rangetoa specifies what format is to be used
64 for the conversion. The value 0 (not the ASCII character '0', but a
65 zero value) specifies a reasonable default, and is in fact the only
66 format currently available. This parameter is a hedge against future
67 needs.
68 Atoasr returns NULL for success and a pointer to a string-literal error
70 message for failure; see DIAGNOSTICS. Rangetoa returns 0 for a fail‐
71 ure, and otherwise always returns the size of buffer which would be
72 needed to accommodate the full conversion result, including terminating
73 NUL; it is the caller's responsibility to check this against the size
74 of the provided buffer to determine whether truncation has occurred.
75
77 ipsec_atoaddr(3), ipsec_atosubnet(3)
78
80 Fatal errors in atoasr are: empty input; error in ipsec_atoaddr(3) or
81 ipsec_atosubnet(3) during conversion; begin address of range exceeds
82 end address.
83 Fatal errors in rangetoa are: unknown format.
85
87 Written for the FreeS/WAN project by Henry Spencer.
88
90 The restriction of error reports to literal strings (so that callers
91 don't need to worry about freeing them or copying them) does limit the
92 precision of error reporting.
93 The error-reporting convention lends itself to slightly obscure code,
95 because many readers will not think of NULL as signifying success. A
96 good way to make it clearer is to write something like:
97 const char *error;
99 error = atoasr( /* ... */ );
101 if (error != NULL) {
102 /* something went wrong */
103 11 June 2001 IPSEC_ATOASR(3)