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[/] [or1k/] [trunk/] [rtems/] [c/] [src/] [libnetworking/] [libc/] [ns_name.c] - Blame information for rev 1765

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/*
 * Copyright (c) 1996 by Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */
 
#if !defined(__rtems__)
#if !defined(LINT) && !defined(CODECENTER)
static char rcsid[] = "$Id: ns_name.c,v 1.2 2001-09-27 12:01:53 chris Exp $";
#endif /* not lint */
#endif /* not rtems */
 
#include <sys/types.h>
 
#include <netinet/in.h>
#include <arpa/nameser.h>
 
#include <errno.h>
#include <resolv.h>
#include <string.h>
 
/* Data. */
 
static char             digits[] = "0123456789";
 
/* Forward. */
 
static int              special(int);
static int              printable(int);
static int              dn_find(const u_char *, const u_char *,
                                const u_char * const *,
                                const u_char * const *);
 
/* Public. */
 
/*
 * ns_name_ntop(src, dst, dstsiz)
 *      Convert an encoded domain name to printable ascii as per RFC1035.
 * return:
 *      Number of bytes written to buffer, or -1 (with errno set)
 * notes:
 *      The root is returned as "."
 *      All other domains are returned in non absolute form
 */
int
ns_name_ntop(const u_char *src, char *dst, size_t dstsiz) {
        const u_char *cp;
        char *dn, *eom;
        u_char c;
        u_int n;
 
        cp = src;
        dn = dst;
        eom = dst + dstsiz;
 
        while ((n = *cp++) != 0) {
                if ((n & NS_CMPRSFLGS) != 0) {
                        /* Some kind of compression pointer. */
                        errno = EMSGSIZE;
                        return (-1);
                }
                if (dn != dst) {
                        if (dn >= eom) {
                                errno = EMSGSIZE;
                                return (-1);
                        }
                        *dn++ = '.';
                }
                if (dn + n >= eom) {
                        errno = EMSGSIZE;
                        return (-1);
                }
                for ((void)NULL; n > 0; n--) {
                        c = *cp++;
                        if (special(c)) {
                                if (dn + 1 >= eom) {
                                        errno = EMSGSIZE;
                                        return (-1);
                                }
                                *dn++ = '\\';
                                *dn++ = (char)c;
                        } else if (!printable(c)) {
                                if (dn + 3 >= eom) {
                                        errno = EMSGSIZE;
                                        return (-1);
                                }
                                *dn++ = '\\';
                                *dn++ = digits[c / 100];
                                *dn++ = digits[(c % 100) / 10];
                                *dn++ = digits[c % 10];
                        } else {
                                if (dn >= eom) {
                                        errno = EMSGSIZE;
                                        return (-1);
                                }
                                *dn++ = (char)c;
                        }
                }
        }
        if (dn == dst) {
                if (dn >= eom) {
                        errno = EMSGSIZE;
                        return (-1);
                }
                *dn++ = '.';
        }
        if (dn >= eom) {
                errno = EMSGSIZE;
                return (-1);
        }
        *dn++ = '\0';
        return (dn - dst);
}
 
/*
 * ns_name_pton(src, dst, dstsiz)
 *      Convert a ascii string into an encoded domain name as per RFC1035.
 * return:
 *      -1 if it fails
 *      1 if string was fully qualified
 *      0 is string was not fully qualified
 * notes:
 *      Enforces label and domain length limits.
 */
 
int
ns_name_pton(const char *src, u_char *dst, size_t dstsiz) {
        u_char *label, *bp, *eom;
        int c, n, escaped;
        char *cp;
 
        escaped = 0;
        bp = dst;
        eom = dst + dstsiz;
        label = bp++;
 
        while ((c = *src++) != 0) {
                if (escaped) {
                        if ((cp = strchr(digits, c)) != NULL) {
                                n = (cp - digits) * 100;
                                if ((c = *src++) == 0 ||
                                    (cp = strchr(digits, c)) == NULL) {
                                        errno = EMSGSIZE;
                                        return (-1);
                                }
                                n += (cp - digits) * 10;
                                if ((c = *src++) == 0 ||
                                    (cp = strchr(digits, c)) == NULL) {
                                        errno = EMSGSIZE;
                                        return (-1);
                                }
                                n += (cp - digits);
                                if (n > 255) {
                                        errno = EMSGSIZE;
                                        return (-1);
                                }
                                c = n;
                        }
                        escaped = 0;
                } else if (c == '\\') {
                        escaped = 1;
                        continue;
                } else if (c == '.') {
                        c = (bp - label - 1);
                        if ((c & NS_CMPRSFLGS) != 0) {   /* Label too big. */
                                errno = EMSGSIZE;
                                return (-1);
                        }
                        if (label >= eom) {
                                errno = EMSGSIZE;
                                return (-1);
                        }
                        *label = c;
                        /* Fully qualified ? */
                        if (*src == '\0') {
                                if (c != 0) {
                                        if (bp >= eom) {
                                                errno = EMSGSIZE;
                                                return (-1);
                                        }
                                        *bp++ = '\0';
                                }
                                if ((bp - dst) > MAXCDNAME) {
                                        errno = EMSGSIZE;
                                        return (-1);
                                }
                                return (1);
                        }
                        if (c == 0) {
                                errno = EMSGSIZE;
                                return (-1);
                        }
                        label = bp++;
                        continue;
                }
                if (bp >= eom) {
                        errno = EMSGSIZE;
                        return (-1);
                }
                *bp++ = (u_char)c;
        }
        c = (bp - label - 1);
        if ((c & NS_CMPRSFLGS) != 0) {           /* Label too big. */
                errno = EMSGSIZE;
                return (-1);
        }
        if (label >= eom) {
                errno = EMSGSIZE;
                return (-1);
        }
        *label = c;
        if (c != 0) {
                if (bp >= eom) {
                        errno = EMSGSIZE;
                        return (-1);
                }
                *bp++ = 0;
        }
        if ((bp - dst) > MAXCDNAME) {   /* src too big */
                errno = EMSGSIZE;
                return (-1);
        }
        return (0);
}
 
/*
 * ns_name_unpack(msg, eom, src, dst, dstsiz)
 *      Unpack a domain name from a message, source may be compressed.
 * return:
 *      -1 if it fails, or consumed octets if it succeeds.
 */
int
ns_name_unpack(const u_char *msg, const u_char *eom, const u_char *src,
               u_char *dst, size_t dstsiz)
{
        const u_char *srcp, *dstlim;
        u_char *dstp;
        int n, len, checked;
 
        len = -1;
        checked = 0;
        dstp = dst;
        srcp = src;
        dstlim = dst + dstsiz;
        if (srcp < msg || srcp >= eom) {
                errno = EMSGSIZE;
                return (-1);
        }
        /* Fetch next label in domain name. */
        while ((n = *srcp++) != 0) {
                /* Check for indirection. */
                switch (n & NS_CMPRSFLGS) {
                case 0:
                        /* Limit checks. */
                        if (dstp + n + 1 >= dstlim || srcp + n >= eom) {
                                errno = EMSGSIZE;
                                return (-1);
                        }
                        checked += n + 1;
                        *dstp++ = n;
                        memcpy(dstp, srcp, n);
                        dstp += n;
                        srcp += n;
                        break;
 
                case NS_CMPRSFLGS:
                        if (srcp >= eom) {
                                errno = EMSGSIZE;
                                return (-1);
                        }
                        if (len < 0)
                                len = srcp - src + 1;
                        srcp = msg + (((n & 0x3f) << 8) | (*srcp & 0xff));
                        if (srcp < msg || srcp >= eom) {  /* Out of range. */
                                errno = EMSGSIZE;
                                return (-1);
                        }
                        checked += 2;
                        /*
                         * Check for loops in the compressed name;
                         * if we've looked at the whole message,
                         * there must be a loop.
                         */
                        if (checked >= eom - msg) {
                                errno = EMSGSIZE;
                                return (-1);
                        }
                        break;
 
                default:
                        errno = EMSGSIZE;
                        return (-1);                    /* flag error */
                }
        }
        *dstp = '\0';
        if (len < 0)
                len = srcp - src;
        return (len);
}
 
/*
 * ns_name_pack(src, dst, dstsiz, dnptrs, lastdnptr)
 *      Pack domain name 'domain' into 'comp_dn'.
 * return:
 *      Size of the compressed name, or -1.
 * notes:
 *      'dnptrs' is an array of pointers to previous compressed names.
 *      dnptrs[0] is a pointer to the beginning of the message. The array
 *      ends with NULL.
 *      'lastdnptr' is a pointer to the end of the array pointed to
 *      by 'dnptrs'.
 * Side effects:
 *      The list of pointers in dnptrs is updated for labels inserted into
 *      the message as we compress the name.  If 'dnptr' is NULL, we don't
 *      try to compress names. If 'lastdnptr' is NULL, we don't update the
 *      list.
 */
int
ns_name_pack(const u_char *src, u_char *dst, int dstsiz,
             const u_char **dnptrs, const u_char **lastdnptr)
{
        u_char *dstp;
        const u_char **cpp, **lpp, *eob, *msg;
        const u_char *srcp;
        int n, l;
 
        srcp = src;
        dstp = dst;
        eob = dstp + dstsiz;
        lpp = cpp = NULL;
        if (dnptrs != NULL) {
                if ((msg = *dnptrs++) != NULL) {
                        for (cpp = dnptrs; *cpp != NULL; cpp++)
                                (void)NULL;
                        lpp = cpp;      /* end of list to search */
                }
        } else
                msg = NULL;
 
        /* make sure the domain we are about to add is legal */
        l = 0;
        do {
                n = *srcp;
                if ((n & NS_CMPRSFLGS) != 0) {
                        errno = EMSGSIZE;
                        return (-1);
                }
                l += n + 1;
                if (l > MAXCDNAME) {
                        errno = EMSGSIZE;
                        return (-1);
                }
                srcp += n + 1;
        } while (n != 0);
 
        srcp = src;
        do {
                /* Look to see if we can use pointers. */
                n = *srcp;
                if (n != 0 && msg != NULL) {
                        l = dn_find(srcp, msg, (const u_char * const *)dnptrs,
                                    (const u_char * const *)lpp);
                        if (l >= 0) {
                                if (dstp + 1 >= eob) {
                                        errno = EMSGSIZE;
                                        return (-1);
                                }
                                *dstp++ = (l >> 8) | NS_CMPRSFLGS;
                                *dstp++ = l % 256;
                                return (dstp - dst);
                        }
                        /* Not found, save it. */
                        if (lastdnptr != NULL && cpp < lastdnptr - 1 &&
                            (dstp - msg) < 0x4000) {
                                *cpp++ = dstp;
                                *cpp = NULL;
                        }
                }
                /* copy label to buffer */
                if (n & NS_CMPRSFLGS) {         /* Should not happen. */
                        errno = EMSGSIZE;
                        return (-1);
                }
                if (dstp + 1 + n >= eob) {
                        errno = EMSGSIZE;
                        return (-1);
                }
                memcpy(dstp, srcp, n + 1);
                srcp += n + 1;
                dstp += n + 1;
        } while (n != 0);
 
        if (dstp > eob) {
                if (msg != NULL)
                        *lpp = NULL;
                errno = EMSGSIZE;
                return (-1);
        }
        return (dstp - dst);
}
 
/*
 * ns_name_uncompress(msg, eom, src, dst, dstsiz)
 *      Expand compressed domain name to presentation format.
 * return:
 *      Number of bytes read out of `src', or -1 (with errno set).
 * note:
 *      Root domain returns as "." not "".
 */
int
ns_name_uncompress(const u_char *msg, const u_char *eom, const u_char *src,
                   char *dst, size_t dstsiz)
{
        u_char tmp[NS_MAXCDNAME];
        int n;
 
        if ((n = ns_name_unpack(msg, eom, src, tmp, sizeof tmp)) == -1)
                return (-1);
        if (ns_name_ntop(tmp, dst, dstsiz) == -1)
                return (-1);
        return (n);
}
 
/*
 * ns_name_compress(src, dst, dstsiz, dnptrs, lastdnptr)
 *      Compress a domain name into wire format, using compression pointers.
 * return:
 *      Number of bytes consumed in `dst' or -1 (with errno set).
 * notes:
 *      'dnptrs' is an array of pointers to previous compressed names.
 *      dnptrs[0] is a pointer to the beginning of the message.
 *      The list ends with NULL.  'lastdnptr' is a pointer to the end of the
 *      array pointed to by 'dnptrs'. Side effect is to update the list of
 *      pointers for labels inserted into the message as we compress the name.
 *      If 'dnptr' is NULL, we don't try to compress names. If 'lastdnptr'
 *      is NULL, we don't update the list.
 */
int
ns_name_compress(const char *src, u_char *dst, size_t dstsiz,
                 const u_char **dnptrs, const u_char **lastdnptr)
{
        u_char tmp[NS_MAXCDNAME];
 
        if (ns_name_pton(src, tmp, sizeof tmp) == -1)
                return (-1);
        return (ns_name_pack(tmp, dst, dstsiz, dnptrs, lastdnptr));
}
 
/*
 * ns_name_skip(ptrptr, eom)
 *      Advance *ptrptr to skip over the compressed name it points at.
 * return:
 *      0 on success, -1 (with errno set) on failure.
 */
int
ns_name_skip(const u_char **ptrptr, const u_char *eom) {
        const u_char *cp;
        u_int n;
 
        cp = *ptrptr;
        while (cp < eom && (n = *cp++) != 0) {
                /* Check for indirection. */
                switch (n & NS_CMPRSFLGS) {
                case 0:                  /* normal case, n == len */
                        cp += n;
                        continue;
                case NS_CMPRSFLGS:      /* indirection */
                        cp++;
                        break;
                default:                /* illegal type */
                        errno = EMSGSIZE;
                        return (-1);
                }
                break;
        }
        if (cp > eom) {
                errno = EMSGSIZE;
                return (-1);
        }
        *ptrptr = cp;
        return (0);
}
 
/* Private. */
 
/*
 * special(ch)
 *      Thinking in noninternationalized USASCII (per the DNS spec),
 *      is this characted special ("in need of quoting") ?
 * return:
 *      boolean.
 */
static int
special(int ch) {
        switch (ch) {
        case 0x22: /* '"' */
        case 0x2E: /* '.' */
        case 0x3B: /* ';' */
        case 0x5C: /* '\\' */
        /* Special modifiers in zone files. */
        case 0x40: /* '@' */
        case 0x24: /* '$' */
                return (1);
        default:
                return (0);
        }
}
 
/*
 * printable(ch)
 *      Thinking in noninternationalized USASCII (per the DNS spec),
 *      is this character visible and not a space when printed ?
 * return:
 *      boolean.
 */
static int
printable(int ch) {
        return (ch > 0x20 && ch < 0x7f);
}
 
/*
 *      Thinking in noninternationalized USASCII (per the DNS spec),
 *      convert this character to lower case if it's upper case.
 */
static int
mklower(int ch) {
        if (ch >= 0x41 && ch <= 0x5A)
                return (ch + 0x20);
        return (ch);
}
 
/*
 * dn_find(domain, msg, dnptrs, lastdnptr)
 *      Search for the counted-label name in an array of compressed names.
 * return:
 *      offset from msg if found, or -1.
 * notes:
 *      dnptrs is the pointer to the first name on the list,
 *      not the pointer to the start of the message.
 */
static int
dn_find(const u_char *domain, const u_char *msg,
        const u_char * const *dnptrs,
        const u_char * const *lastdnptr)
{
        const u_char *dn, *cp, *sp;
        const u_char * const *cpp;
        u_int n;
 
        for (cpp = dnptrs; cpp < lastdnptr; cpp++) {
                dn = domain;
                sp = cp = *cpp;
                while ((n = *cp++) != 0) {
                        /*
                         * check for indirection
                         */
                        switch (n & NS_CMPRSFLGS) {
                        case 0:                  /* normal case, n == len */
                                if (n != *dn++)
                                        goto next;
                                for ((void)NULL; n > 0; n--)
                                        if (mklower(*dn++) != mklower(*cp++))
                                                goto next;
                                /* Is next root for both ? */
                                if (*dn == '\0' && *cp == '\0')
                                        return (sp - msg);
                                if (*dn)
                                        continue;
                                goto next;
 
                        case NS_CMPRSFLGS:      /* indirection */
                                cp = msg + (((n & 0x3f) << 8) | *cp);
                                break;
 
                        default:        /* illegal type */
                                errno = EMSGSIZE;
                                return (-1);
                        }
                }
 next: ;
        }
        errno = ENOENT;
        return (-1);
}

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[/] [or1k/] [trunk/] [rtems/] [c/] [src/] [libnetworking/] [libc/] [ns_name.c] - Blame information for rev 1765

Line No.	Rev	Author	Line
1	158	chris	`/*`
2			`* Copyright (c) 1996 by Internet Software Consortium.`
3			`*`
4			`* Permission to use, copy, modify, and distribute this software for any`
5			`* purpose with or without fee is hereby granted, provided that the above`
6			`* copyright notice and this permission notice appear in all copies.`
7			`*`
8			`* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS`
9			`* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES`
10			`* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE`
11			`* CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL`
12			`* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR`
13			`* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS`
14			`* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS`
15			`* SOFTWARE.`
16			`*/`
17
18			`#if !defined(__rtems__)`
19			`#if !defined(LINT) && !defined(CODECENTER)`
20	208	chris	`static char rcsid[] = "$Id: ns_name.c,v 1.2 2001-09-27 12:01:53 chris Exp $";`
21	158	chris	`#endif /* not lint */`
22			`#endif /* not rtems */`
23
24			`#include <sys/types.h>`
25
26			`#include <netinet/in.h>`
27			`#include <arpa/nameser.h>`
28
29			`#include <errno.h>`
30			`#include <resolv.h>`
31			`#include <string.h>`
32
33			`/* Data. */`
34
35			`static char digits[] = "0123456789";`
36
37			`/* Forward. */`
38
39			`static int special(int);`
40			`static int printable(int);`
41			`static int dn_find(const u_char , const u_char ,`
42			`const u_char * const *,`
43			`const u_char * const *);`
44
45			`/* Public. */`
46
47			`/*`
48			`* ns_name_ntop(src, dst, dstsiz)`
49			`* Convert an encoded domain name to printable ascii as per RFC1035.`
50			`* return:`
51			`* Number of bytes written to buffer, or -1 (with errno set)`
52			`* notes:`
53			`* The root is returned as "."`
54			`* All other domains are returned in non absolute form`
55			`*/`
56			`int`
57			`ns_name_ntop(const u_char src, char dst, size_t dstsiz) {`
58			`const u_char *cp;`
59			`char dn, eom;`
60			`u_char c;`
61			`u_int n;`
62
63			`cp = src;`
64			`dn = dst;`
65			`eom = dst + dstsiz;`
66
67			`while ((n = *cp++) != 0) {`
68			`if ((n & NS_CMPRSFLGS) != 0) {`
69			`/* Some kind of compression pointer. */`
70			`errno = EMSGSIZE;`
71			`return (-1);`
72			`}`
73			`if (dn != dst) {`
74			`if (dn >= eom) {`
75			`errno = EMSGSIZE;`
76			`return (-1);`
77			`}`
78			`*dn++ = '.';`
79			`}`
80			`if (dn + n >= eom) {`
81			`errno = EMSGSIZE;`
82			`return (-1);`
83			`}`
84			`for ((void)NULL; n > 0; n--) {`
85			`c = *cp++;`
86			`if (special(c)) {`
87			`if (dn + 1 >= eom) {`
88			`errno = EMSGSIZE;`
89			`return (-1);`
90			`}`
91			`*dn++ = '\\';`
92			`*dn++ = (char)c;`
93			`} else if (!printable(c)) {`
94			`if (dn + 3 >= eom) {`
95			`errno = EMSGSIZE;`
96			`return (-1);`
97			`}`
98			`*dn++ = '\\';`
99			`*dn++ = digits[c / 100];`
100			`*dn++ = digits[(c % 100) / 10];`
101			`*dn++ = digits[c % 10];`
102			`} else {`
103			`if (dn >= eom) {`
104			`errno = EMSGSIZE;`
105			`return (-1);`
106			`}`
107			`*dn++ = (char)c;`
108			`}`
109			`}`
110			`}`
111			`if (dn == dst) {`
112			`if (dn >= eom) {`
113			`errno = EMSGSIZE;`
114			`return (-1);`
115			`}`
116			`*dn++ = '.';`
117			`}`
118			`if (dn >= eom) {`
119			`errno = EMSGSIZE;`
120			`return (-1);`
121			`}`
122			`*dn++ = '\0';`
123			`return (dn - dst);`
124			`}`
125
126			`/*`
127			`* ns_name_pton(src, dst, dstsiz)`
128			`* Convert a ascii string into an encoded domain name as per RFC1035.`
129			`* return:`
130			`* -1 if it fails`
131			`* 1 if string was fully qualified`
132			`* 0 is string was not fully qualified`
133			`* notes:`
134			`* Enforces label and domain length limits.`
135			`*/`
136
137			`int`
138			`ns_name_pton(const char src, u_char dst, size_t dstsiz) {`
139			`u_char label, bp, *eom;`
140			`int c, n, escaped;`
141			`char *cp;`
142
143			`escaped = 0;`
144			`bp = dst;`
145			`eom = dst + dstsiz;`
146			`label = bp++;`
147
148			`while ((c = *src++) != 0) {`
149			`if (escaped) {`
150			`if ((cp = strchr(digits, c)) != NULL) {`
151			`n = (cp - digits) * 100;`
152			`if ((c = *src++) == 0 \|\|`
153			`(cp = strchr(digits, c)) == NULL) {`
154			`errno = EMSGSIZE;`
155			`return (-1);`
156			`}`
157			`n += (cp - digits) * 10;`
158			`if ((c = *src++) == 0 \|\|`
159			`(cp = strchr(digits, c)) == NULL) {`
160			`errno = EMSGSIZE;`
161			`return (-1);`
162			`}`
163			`n += (cp - digits);`
164			`if (n > 255) {`
165			`errno = EMSGSIZE;`
166			`return (-1);`
167			`}`
168			`c = n;`
169			`}`
170			`escaped = 0;`
171			`} else if (c == '\\') {`
172			`escaped = 1;`
173			`continue;`
174			`} else if (c == '.') {`
175			`c = (bp - label - 1);`
176			`if ((c & NS_CMPRSFLGS) != 0) { /* Label too big. */`
177			`errno = EMSGSIZE;`
178			`return (-1);`
179			`}`
180			`if (label >= eom) {`
181			`errno = EMSGSIZE;`
182			`return (-1);`
183			`}`
184			`*label = c;`
185			`/* Fully qualified ? */`
186			`if (*src == '\0') {`
187			`if (c != 0) {`
188			`if (bp >= eom) {`
189			`errno = EMSGSIZE;`
190			`return (-1);`
191			`}`
192			`*bp++ = '\0';`
193			`}`
194			`if ((bp - dst) > MAXCDNAME) {`
195			`errno = EMSGSIZE;`
196			`return (-1);`
197			`}`
198			`return (1);`
199			`}`
200			`if (c == 0) {`
201			`errno = EMSGSIZE;`
202			`return (-1);`
203			`}`
204			`label = bp++;`
205			`continue;`
206			`}`
207			`if (bp >= eom) {`
208			`errno = EMSGSIZE;`
209			`return (-1);`
210			`}`
211			`*bp++ = (u_char)c;`
212			`}`
213			`c = (bp - label - 1);`
214			`if ((c & NS_CMPRSFLGS) != 0) { /* Label too big. */`
215			`errno = EMSGSIZE;`
216			`return (-1);`
217			`}`
218			`if (label >= eom) {`
219			`errno = EMSGSIZE;`
220			`return (-1);`
221			`}`
222			`*label = c;`
223			`if (c != 0) {`
224			`if (bp >= eom) {`
225			`errno = EMSGSIZE;`
226			`return (-1);`
227			`}`
228			`*bp++ = 0;`
229			`}`
230			`if ((bp - dst) > MAXCDNAME) { /* src too big */`
231			`errno = EMSGSIZE;`
232			`return (-1);`
233			`}`
234			`return (0);`
235			`}`
236
237			`/*`
238			`* ns_name_unpack(msg, eom, src, dst, dstsiz)`
239			`* Unpack a domain name from a message, source may be compressed.`
240			`* return:`
241			`* -1 if it fails, or consumed octets if it succeeds.`
242			`*/`
243			`int`
244			`ns_name_unpack(const u_char msg, const u_char eom, const u_char *src,`
245			`u_char *dst, size_t dstsiz)`
246			`{`
247			`const u_char srcp, dstlim;`
248			`u_char *dstp;`
249			`int n, len, checked;`
250
251			`len = -1;`
252			`checked = 0;`
253			`dstp = dst;`
254			`srcp = src;`
255			`dstlim = dst + dstsiz;`
256			`if (srcp < msg \|\| srcp >= eom) {`
257			`errno = EMSGSIZE;`
258			`return (-1);`
259			`}`
260			`/* Fetch next label in domain name. */`
261			`while ((n = *srcp++) != 0) {`
262			`/* Check for indirection. */`
263			`switch (n & NS_CMPRSFLGS) {`
264			`case 0:`
265			`/* Limit checks. */`
266			`if (dstp + n + 1 >= dstlim \|\| srcp + n >= eom) {`
267			`errno = EMSGSIZE;`
268			`return (-1);`
269			`}`
270			`checked += n + 1;`
271			`*dstp++ = n;`
272			`memcpy(dstp, srcp, n);`
273			`dstp += n;`
274			`srcp += n;`
275			`break;`
276
277			`case NS_CMPRSFLGS:`
278			`if (srcp >= eom) {`
279			`errno = EMSGSIZE;`
280			`return (-1);`
281			`}`
282			`if (len < 0)`
283			`len = srcp - src + 1;`
284			`srcp = msg + (((n & 0x3f) << 8) \| (*srcp & 0xff));`
285			`if (srcp < msg \|\| srcp >= eom) { /* Out of range. */`
286			`errno = EMSGSIZE;`
287			`return (-1);`
288			`}`
289			`checked += 2;`
290			`/*`
291			`* Check for loops in the compressed name;`
292			`* if we've looked at the whole message,`
293			`* there must be a loop.`
294			`*/`
295			`if (checked >= eom - msg) {`
296			`errno = EMSGSIZE;`
297			`return (-1);`
298			`}`
299			`break;`
300
301			`default:`
302			`errno = EMSGSIZE;`
303			`return (-1); /* flag error */`
304			`}`
305			`}`
306			`*dstp = '\0';`
307			`if (len < 0)`
308			`len = srcp - src;`
309			`return (len);`
310			`}`
311
312			`/*`
313			`* ns_name_pack(src, dst, dstsiz, dnptrs, lastdnptr)`
314			`* Pack domain name 'domain' into 'comp_dn'.`
315			`* return:`
316			`* Size of the compressed name, or -1.`
317			`* notes:`
318			`* 'dnptrs' is an array of pointers to previous compressed names.`
319			`* dnptrs[0] is a pointer to the beginning of the message. The array`
320			`* ends with NULL.`
321			`* 'lastdnptr' is a pointer to the end of the array pointed to`
322			`* by 'dnptrs'.`
323			`* Side effects:`
324			`* The list of pointers in dnptrs is updated for labels inserted into`
325			`* the message as we compress the name. If 'dnptr' is NULL, we don't`
326			`* try to compress names. If 'lastdnptr' is NULL, we don't update the`
327			`* list.`
328			`*/`
329			`int`
330			`ns_name_pack(const u_char src, u_char dst, int dstsiz,`
331			`const u_char dnptrs, const u_char lastdnptr)`
332			`{`
333			`u_char *dstp;`
334			`const u_char cpp, lpp, eob, msg;`
335			`const u_char *srcp;`
336			`int n, l;`
337
338			`srcp = src;`
339			`dstp = dst;`
340			`eob = dstp + dstsiz;`
341			`lpp = cpp = NULL;`
342			`if (dnptrs != NULL) {`
343			`if ((msg = *dnptrs++) != NULL) {`
344			`for (cpp = dnptrs; *cpp != NULL; cpp++)`
345			`(void)NULL;`
346			`lpp = cpp; /* end of list to search */`
347			`}`
348			`} else`
349			`msg = NULL;`
350
351			`/* make sure the domain we are about to add is legal */`
352			`l = 0;`
353			`do {`
354			`n = *srcp;`
355			`if ((n & NS_CMPRSFLGS) != 0) {`
356			`errno = EMSGSIZE;`
357			`return (-1);`
358			`}`
359			`l += n + 1;`
360			`if (l > MAXCDNAME) {`
361			`errno = EMSGSIZE;`
362			`return (-1);`
363			`}`
364			`srcp += n + 1;`
365			`} while (n != 0);`
366
367			`srcp = src;`
368			`do {`
369			`/* Look to see if we can use pointers. */`
370			`n = *srcp;`
371			`if (n != 0 && msg != NULL) {`
372			`l = dn_find(srcp, msg, (const u_char * const *)dnptrs,`
373			`(const u_char * const *)lpp);`
374			`if (l >= 0) {`
375			`if (dstp + 1 >= eob) {`
376			`errno = EMSGSIZE;`
377			`return (-1);`
378			`}`
379			`*dstp++ = (l >> 8) \| NS_CMPRSFLGS;`
380			`*dstp++ = l % 256;`
381			`return (dstp - dst);`
382			`}`
383			`/* Not found, save it. */`
384			`if (lastdnptr != NULL && cpp < lastdnptr - 1 &&`
385			`(dstp - msg) < 0x4000) {`
386			`*cpp++ = dstp;`
387			`*cpp = NULL;`
388			`}`
389			`}`
390			`/* copy label to buffer */`
391			`if (n & NS_CMPRSFLGS) { /* Should not happen. */`
392			`errno = EMSGSIZE;`
393			`return (-1);`
394			`}`
395			`if (dstp + 1 + n >= eob) {`
396			`errno = EMSGSIZE;`
397			`return (-1);`
398			`}`
399			`memcpy(dstp, srcp, n + 1);`
400			`srcp += n + 1;`
401			`dstp += n + 1;`
402			`} while (n != 0);`
403
404			`if (dstp > eob) {`
405			`if (msg != NULL)`
406			`*lpp = NULL;`
407			`errno = EMSGSIZE;`
408			`return (-1);`
409			`}`
410			`return (dstp - dst);`
411			`}`
412
413			`/*`
414			`* ns_name_uncompress(msg, eom, src, dst, dstsiz)`
415			`* Expand compressed domain name to presentation format.`
416			`* return:`
417			* Number of bytes read out of `src', or -1 (with errno set).
418			`* note:`
419			`* Root domain returns as "." not "".`
420			`*/`
421			`int`
422			`ns_name_uncompress(const u_char msg, const u_char eom, const u_char *src,`
423			`char *dst, size_t dstsiz)`
424			`{`
425			`u_char tmp[NS_MAXCDNAME];`
426			`int n;`
427
428			`if ((n = ns_name_unpack(msg, eom, src, tmp, sizeof tmp)) == -1)`
429			`return (-1);`
430			`if (ns_name_ntop(tmp, dst, dstsiz) == -1)`
431			`return (-1);`
432			`return (n);`
433			`}`
434
435			`/*`
436			`* ns_name_compress(src, dst, dstsiz, dnptrs, lastdnptr)`
437			`* Compress a domain name into wire format, using compression pointers.`
438			`* return:`
439			* Number of bytes consumed in `dst' or -1 (with errno set).
440			`* notes:`
441			`* 'dnptrs' is an array of pointers to previous compressed names.`
442			`* dnptrs[0] is a pointer to the beginning of the message.`
443			`* The list ends with NULL. 'lastdnptr' is a pointer to the end of the`
444			`* array pointed to by 'dnptrs'. Side effect is to update the list of`
445			`* pointers for labels inserted into the message as we compress the name.`
446			`* If 'dnptr' is NULL, we don't try to compress names. If 'lastdnptr'`
447			`* is NULL, we don't update the list.`
448			`*/`
449			`int`
450			`ns_name_compress(const char src, u_char dst, size_t dstsiz,`
451			`const u_char dnptrs, const u_char lastdnptr)`
452			`{`
453			`u_char tmp[NS_MAXCDNAME];`
454
455			`if (ns_name_pton(src, tmp, sizeof tmp) == -1)`
456			`return (-1);`
457			`return (ns_name_pack(tmp, dst, dstsiz, dnptrs, lastdnptr));`
458			`}`
459
460			`/*`
461			`* ns_name_skip(ptrptr, eom)`
462			`* Advance *ptrptr to skip over the compressed name it points at.`
463			`* return:`
464			`* 0 on success, -1 (with errno set) on failure.`
465			`*/`
466			`int`
467			`ns_name_skip(const u_char *ptrptr, const u_char eom) {`
468			`const u_char *cp;`
469			`u_int n;`
470
471			`cp = *ptrptr;`
472			`while (cp < eom && (n = *cp++) != 0) {`
473			`/* Check for indirection. */`
474			`switch (n & NS_CMPRSFLGS) {`
475			`case 0: /* normal case, n == len */`
476			`cp += n;`
477			`continue;`
478			`case NS_CMPRSFLGS: /* indirection */`
479			`cp++;`
480			`break;`
481			`default: /* illegal type */`
482			`errno = EMSGSIZE;`
483			`return (-1);`
484			`}`
485			`break;`
486			`}`
487			`if (cp > eom) {`
488			`errno = EMSGSIZE;`
489			`return (-1);`
490			`}`
491			`*ptrptr = cp;`
492			`return (0);`
493			`}`
494
495			`/* Private. */`
496
497			`/*`
498			`* special(ch)`
499			`* Thinking in noninternationalized USASCII (per the DNS spec),`
500			`* is this characted special ("in need of quoting") ?`
501			`* return:`
502			`* boolean.`
503			`*/`
504			`static int`
505			`special(int ch) {`
506			`switch (ch) {`
507			`case 0x22: /* '"' */`
508			`case 0x2E: /* '.' */`
509			`case 0x3B: /* ';' */`
510			`case 0x5C: /* '\\' */`
511			`/* Special modifiers in zone files. */`
512			`case 0x40: /* '@' */`
513			`case 0x24: /* '$' */`
514			`return (1);`
515			`default:`
516			`return (0);`
517			`}`
518			`}`
519
520			`/*`
521			`* printable(ch)`
522			`* Thinking in noninternationalized USASCII (per the DNS spec),`
523			`* is this character visible and not a space when printed ?`
524			`* return:`
525			`* boolean.`
526			`*/`
527			`static int`
528			`printable(int ch) {`
529			`return (ch > 0x20 && ch < 0x7f);`
530			`}`
531
532			`/*`
533			`* Thinking in noninternationalized USASCII (per the DNS spec),`
534			`* convert this character to lower case if it's upper case.`
535			`*/`
536			`static int`
537			`mklower(int ch) {`
538			`if (ch >= 0x41 && ch <= 0x5A)`
539			`return (ch + 0x20);`
540			`return (ch);`
541			`}`
542
543			`/*`
544			`* dn_find(domain, msg, dnptrs, lastdnptr)`
545			`* Search for the counted-label name in an array of compressed names.`
546			`* return:`
547			`* offset from msg if found, or -1.`
548			`* notes:`
549			`* dnptrs is the pointer to the first name on the list,`
550			`* not the pointer to the start of the message.`
551			`*/`
552			`static int`
553			`dn_find(const u_char domain, const u_char msg,`
554			`const u_char * const *dnptrs,`
555			`const u_char * const *lastdnptr)`
556			`{`
557			`const u_char dn, cp, *sp;`
558			`const u_char * const *cpp;`
559			`u_int n;`
560
561			`for (cpp = dnptrs; cpp < lastdnptr; cpp++) {`
562			`dn = domain;`
563			`sp = cp = *cpp;`
564			`while ((n = *cp++) != 0) {`
565			`/*`
566			`* check for indirection`
567			`*/`
568			`switch (n & NS_CMPRSFLGS) {`
569			`case 0: /* normal case, n == len */`
570			`if (n != *dn++)`
571			`goto next;`
572			`for ((void)NULL; n > 0; n--)`
573			`if (mklower(dn++) != mklower(cp++))`
574			`goto next;`
575			`/* Is next root for both ? */`
576			`if (dn == '\0' && cp == '\0')`
577			`return (sp - msg);`
578			`if (*dn)`
579			`continue;`
580			`goto next;`
581
582			`case NS_CMPRSFLGS: /* indirection */`
583			`cp = msg + (((n & 0x3f) << 8) \| *cp);`
584			`break;`
585
586			`default: /* illegal type */`
587			`errno = EMSGSIZE;`
588			`return (-1);`
589			`}`
590			`}`
591			`next: ;`
592			`}`
593			`errno = ENOENT;`
594			`return (-1);`
595			`}`