1 /*++
2 /* NAME
3 /* dsn_util 3
4 /* SUMMARY
5 /* DSN status parsing routines
6 /* SYNOPSIS
7 /* #include <dsn_util.h>
8 /*
9 /* #define DSN_SIZE ...
10 /*
11 /* typedef struct { ... } DSN_BUF;
12 /*
13 /* typedef struct {
14 /* .in +4
15 /* DSN_STAT dsn; /* RFC 3463 status */
16 /* const char *text; /* Free text */
17 /* .in -4
18 /* } DSN_SPLIT;
19 /*
20 /* DSN_SPLIT *dsn_split(dp, def_dsn, text)
21 /* DSN_SPLIT *dp;
22 /* const char *def_dsn;
23 /* const char *text;
24 /*
25 /* char *dsn_prepend(def_dsn, text)
26 /* const char *def_dsn;
27 /* const char *text;
28 /*
29 /* size_t dsn_valid(text)
30 /* const char *text;
31 /*
32 /* void DSN_UPDATE(dsn_buf, dsn, len)
33 /* DSN_BUF dsn_buf;
34 /* const char *dsn;
35 /* size_t len;
36 /*
37 /* const char *DSN_CODE(dsn_buf)
38 /* DSN_BUF dsn_buf;
39 /*
40 /* char *DSN_CLASS(dsn_buf)
41 /* DSN_BUF dsn_buf;
42 /* DESCRIPTION
43 /* The functions in this module manipulate pairs of RFC 3463
44 /* status codes and descriptive free text.
45 /*
46 /* dsn_split() splits text into an RFC 3463 status code and
47 /* descriptive free text. When the text does not start with
48 /* a status code, the specified default status code is used
49 /* instead. Whitespace before the optional status code or
50 /* text is skipped. dsn_split() returns a copy of the RFC
51 /* 3463 status code, and returns a pointer to (not copy of)
52 /* the remainder of the text. The result value is the first
53 /* argument.
54 /*
55 /* dsn_prepend() prepends the specified default RFC 3463 status
56 /* code to the specified text if no status code is present in
57 /* the text. This function produces the same result as calling
58 /* concatenate() with the results from dsn_split(). The result
59 /* should be passed to myfree(). Whitespace before the optional
60 /* status code or text is skipped.
61 /*
62 /* dsn_valid() returns the length of the RFC 3463 status code
63 /* at the beginning of text, or zero. It does not skip initial
64 /* whitespace.
65 /*
66 /* Arguments:
67 /* .IP def_dsn
68 /* Null-terminated default RFC 3463 status code that will be
69 /* used when the free text does not start with one.
70 /* .IP dp
71 /* Pointer to storage for copy of DSN status code, and for
72 /* pointer to free text.
73 /* .IP dsn
74 /* Null-terminated RFC 3463 status code.
75 /* .IP text
76 /* Null-terminated free text.
77 /* SEE ALSO
78 /* msg(3) diagnostics interface
79 /* DIAGNOSTICS
80 /* Panic: invalid default DSN code.
81 /* LICENSE
82 /* .ad
83 /* .fi
84 /* The Secure Mailer license must be distributed with this software.
85 /* AUTHOR(S)
86 /* Wietse Venema
87 /* IBM T.J. Watson Research
88 /* P.O. Box 704
89 /* Yorktown Heights, NY 10598, USA
90 /*--*/
91
92 /* System library. */
93
94 #include <sys_defs.h>
95 #include <stdarg.h>
96 #include <string.h>
97 #include <ctype.h>
98
99 /* Utility library. */
100
101 #include <msg.h>
102 #include <mymalloc.h>
103 #include <vstring.h>
104 #include <stringops.h>
105
106 /* Global library. */
107
108 #include <dsn_util.h>
109
110 /* dsn_valid - check RFC 3463 enhanced status code, return length or zero */
111
dsn_valid(const char * text)112 size_t dsn_valid(const char *text)
113 {
114 const unsigned char *cp = (unsigned char *) text;
115 size_t len;
116
117 /* First portion is one digit followed by dot. */
118 if ((cp[0] != '2' && cp[0] != '4' && cp[0] != '5') || cp[1] != '.')
119 return (0);
120
121 /* Second portion is 1-3 digits followed by dot. */
122 cp += 2;
123 if ((len = strspn((char *) cp, "0123456789")) < 1 || len > DSN_DIGS2
124 || cp[len] != '.')
125 return (0);
126
127 /* Last portion is 1-3 digits followed by end-of-string or whitespace. */
128 cp += len + 1;
129 if ((len = strspn((char *) cp, "0123456789")) < 1 || len > DSN_DIGS3
130 || (cp[len] != 0 && !ISSPACE(cp[len])))
131 return (0);
132
133 return (((char *) cp - text) + len);
134 }
135
136 /* dsn_split - split text into DSN and text */
137
dsn_split(DSN_SPLIT * dp,const char * def_dsn,const char * text)138 DSN_SPLIT *dsn_split(DSN_SPLIT *dp, const char *def_dsn, const char *text)
139 {
140 const char *myname = "dsn_split";
141 const char *cp = text;
142 size_t len;
143
144 /*
145 * Look for an optional RFC 3463 enhanced status code.
146 *
147 * XXX If we want to enforce that the first digit of the status code in the
148 * text matches the default status code, then pipe_command() needs to be
149 * changed. It currently auto-detects the reply code without knowing in
150 * advance if the result will start with '4' or '5'.
151 */
152 while (ISSPACE(*cp))
153 cp++;
154 if ((len = dsn_valid(cp)) > 0) {
155 strncpy(dp->dsn.data, cp, len);
156 dp->dsn.data[len] = 0;
157 cp += len + 1;
158 } else if ((len = dsn_valid(def_dsn)) > 0) {
159 strncpy(dp->dsn.data, def_dsn, len);
160 dp->dsn.data[len] = 0;
161 } else {
162 msg_panic("%s: bad default status \"%s\"", myname, def_dsn);
163 }
164
165 /*
166 * The remainder is free text.
167 */
168 while (ISSPACE(*cp))
169 cp++;
170 dp->text = cp;
171
172 return (dp);
173 }
174
175 /* dsn_prepend - prepend optional status to text, result on heap */
176
dsn_prepend(const char * def_dsn,const char * text)177 char *dsn_prepend(const char *def_dsn, const char *text)
178 {
179 DSN_SPLIT dp;
180
181 dsn_split(&dp, def_dsn, text);
182 return (concatenate(DSN_STATUS(dp.dsn), " ", dp.text, (char *) 0));
183 }
184