*/
/* Original copyright ISC as above.
- * Code modified specifically for ircd use from the following orginal files
+ * Code modified specifically for ircd use from the following original files
* in bind ...
*
* res_comp.c
#include <stdlib.h>
#include <stdio.h>
-#define NS_TYPE_ELT 0x40 /* EDNS0 extended label type */
-#define DNS_LABELTYPE_BITSTRING 0x41
-#define MAXLINE 128
+#define NS_TYPE_ELT 0x40 /**< EDNS0 extended label type */
+#define DNS_LABELTYPE_BITSTRING 0x41 /**< Bitstring label */
+#define MAXLINE 128 /**< Maximum line length for resolv.conf */
-/* $Id$ */
+/** @file
+ * @brief DNS resolver library functions.
+ * @version $Id$
+ */
+/** Array of nameserver addresses. */
struct irc_sockaddr irc_nsaddr_list[IRCD_MAXNS];
-int irc_nscount = 0;
+/** Number of nameservers in #irc_nsaddr_list. */
+int irc_nscount;
+/** Local domain to use as a search suffix. */
char irc_domain[HOSTLEN + 1];
+/** Maps hex digits to their values, or -1 for other characters. */
static const char digitvalue[256] = {
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*16*/
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*32*/
};
static int parse_resvconf(void);
-static void add_nameserver(char *arg);
+/** Array of decimal digits, indexed by value. */
static const char digits[] = "0123456789";
static int labellen(const unsigned char *lp);
static int special(int ch);
const unsigned char **dnptrs, const unsigned char **lastdnptr);
static int irc_dn_find(const unsigned char *, const unsigned char *, const unsigned char * const *,
const unsigned char * const *);
-static int irc_encode_bitsring(const char **, const char *, unsigned char **, unsigned char **,
+static int irc_encode_bitsring(const char **, const char *, unsigned char **, unsigned char **,
const char *);
static int mklower(int ch);
-
+
+/** Initialize the resolver library.
+ * @return Zero on success, non-zero on failure.
+ */
int
irc_res_init(void)
{
- irc_nscount = 0;
- return(parse_resvconf());
+ return (irc_nscount == 0) ? parse_resvconf() : 0;
}
-/* parse_resvconf()
- *
- * inputs - NONE
- * output - -1 if failure 0 if success
- * side effects - fills in irc_nsaddr_list
+/** Read resolver configuration file for domain and nameserver lines.
+ * The "domain" line is used to overwrite #irc_domain.
+ * Addresses in "nameserver" lines are appended to #irc_nsaddr_list.
+ * @return Zero on success, non-zero on failure.
*/
static int
parse_resvconf(void)
continue;
p = input;
- /* skip until something thats not a space is seen */
+ /* skip until something that's not a space is seen */
while (IsSpace(*p))
p++;
/* if at this point, have a '\0' then continue */
return(0);
}
-/* add_nameserver()
- *
- * input - either an IPV4 address in dotted quad
- * or an IPV6 address in : format
- * output - NONE
- * side effects - entry in irc_nsaddr_list is filled in as needed
+/** Add a resolver to #irc_nsaddr_list.
+ * @param[in] arg Dotted quad or IPv6 text form of nameserver address.
*/
-static void
-add_nameserver(char *arg)
+void
+add_nameserver(const char *arg)
{
struct irc_sockaddr res;
/* Done max number of nameservers? */
- if ((irc_nscount + 1) >= IRCD_MAXNS)
+ if (irc_nscount >= IRCD_MAXNS)
return;
/* Failure converting from numeric string? */
irc_nscount++;
}
-/*
- * Expand compressed domain name 'comp_dn' to full domain name.
- * 'msg' is a pointer to the begining of the message,
- * 'eomorig' points to the first location after the message,
- * 'exp_dn' is a pointer to a buffer of size 'length' for the result.
- * Return size of compressed name or -1 if there was an error.
+/**
+ * Expand compressed domain name to full domain name.
+ * Like irc_ns_name_uncompress(), but checks for a well-formed result.
+ * @param[in] msg Pointer to the beginning of the message.
+ * @param[in] eom First location after the message.
+ * @param[in] src Pointer to where to starting decoding.
+ * @param[out] dst Output buffer.
+ * @param[in] dstsiz Number of bytes that can be written to \a dst.
+ * @return Number of bytes written to \a dst.
*/
int
irc_dn_expand(const unsigned char *msg, const unsigned char *eom,
return(n);
}
-/*
- * irc_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 "".
+/**
+ * Expand compressed domain name to full domain name.
+ * @param[in] msg Pointer to the beginning of the message.
+ * @param[in] eom First location after the message.
+ * @param[in] src Pointer to where to starting decoding.
+ * @param[out] dst Output buffer.
+ * @param[in] dstsiz Number of bytes that can be written to \a dst.
+ * @return Number of bytes written to \a dst.
*/
int
irc_ns_name_uncompress(const unsigned char *msg, const unsigned char *eom,
return(-1);
return(n);
}
-/*
- * irc_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.
+
+/**
+ * Unpack compressed domain name to uncompressed form.
+ * @param[in] msg Pointer to the beginning of the message.
+ * @param[in] eom First location after the message.
+ * @param[in] src Pointer to where to starting decoding.
+ * @param[out] dst Output buffer.
+ * @param[in] dstsiz Number of bytes that can be written to \a dst.
+ * @return Number of bytes written to \a dst.
*/
int
irc_ns_name_unpack(const unsigned char *msg, const unsigned char *eom,
return (len);
}
-/*
- * irc_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
+/**
+ * Convert RFC1035 length-prefixed tag sequence to printable ASCII.
+ * @param[in] src Input tag sequence (effectively NUL terminated).
+ * @param[out] dst Buffer for uncompressed output.
+ * @param[in] dstsiz Number of bytes that can be written to \a dst.
+ * @return Number of bytes written to \a dst.
*/
int
irc_ns_name_ntop(const char *src, char *dst, size_t dstsiz)
return (dn - dst);
}
-/*
- * Pack domain name 'exp_dn' in presentation form into 'comp_dn'.
- * Return the size of the compressed name or -1.
- * 'length' is the size of the array pointed to by 'comp_dn'.
+/** Pack domain name from presentation form into compressed format.
+ * @param[in] src Presentation form of name.
+ * @param[out] dst Output buffer.
+ * @param[in] dstsiz Number of bytes that can be written to \a dst.
+ * @param[in,out] dnptrs Array of previously seen labels.
+ * @param[in] lastdnptr End of \a dnptrs array.
+ * @return Number of bytes written to \a dst.
*/
int
irc_dn_comp(const char *src, unsigned char *dst, int dstsiz,
(const unsigned char **)lastdnptr));
}
-/*
- * Skip over a compressed domain name. Return the size or -1.
+/** Skip over a compressed domain name.
+ * @param[in] ptr Start of compressed name.
+ * @param[in] eom End of message.
+ * @return Length of the compressed name, or -1 on error.
*/
int
irc_dn_skipname(const unsigned char *ptr, const unsigned char *eom) {
return(ptr - saveptr);
}
-/*
- * 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.
+/** Advance \a ptrptr to skip over the compressed name it points at.
+ * @param[in,out] ptrptr Pointer to the compressed name.
+ * @param[in] eom End of message.
+ * @return Zero on success; non-zero (with errno set) on failure.
*/
int
irc_ns_name_skip(const unsigned char **ptrptr, const unsigned char *eom)
return(0);
}
+/** Read a 16-bit network-endian value from \a src.
+ * @param[in] src Input data buffer.
+ * @return Value retrieved from buffer.
+ */
unsigned int
irc_ns_get16(const unsigned char *src)
{
return(dst);
}
+/** Read a 32-bit network-endian value from \a src.
+ * @param[in] src Input data buffer.
+ * @return Value retrieved from buffer.
+ */
unsigned long
irc_ns_get32(const unsigned char *src)
{
return(dst);
}
+/** Write a 16-bit network-endian value to \a dst.
+ * @param[in] src Value to write.
+ * @param[out] dst Output buffer.
+ */
void
irc_ns_put16(unsigned int src, unsigned char *dst)
{
IRC_NS_PUT16(src, dst);
}
+/** Write a 32-bit network-endian value to \a dst.
+ * @param[in] src Value to write.
+ * @param[out] dst Output buffer.
+ */
void
irc_ns_put32(unsigned long src, unsigned char *dst)
{
/* From ns_name.c */
-/*
- * special(ch)
- * Thinking in noninternationalized USASCII (per the DNS spec),
- * is this characted special ("in need of quoting") ?
- * return:
- * boolean.
+/** Indicate whether a character needs quoting.
+ * (What RFC does this come from?)
+ * @param[in] ch Character to check for specialness.
+ * @return Non-zero if the character should be quoted.
*/
static int
special(int ch)
}
}
+/** Calculate the length of a particular DNS label.
+ * @param[in] lp Start of label.
+ * @return Length of label, or -1 on error.
+ */
static int
labellen(const unsigned char *lp)
-{
+{
int bitlen;
unsigned char l = *lp;
return((bitlen + 7 ) / 8 + 1);
}
- return(-1); /* unknwon ELT */
+ return(-1); /* unknown ELT */
}
return(l);
}
-/*
- * printable(ch)
- * Thinking in noninternationalized USASCII (per the DNS spec),
- * is this character visible and not a space when printed ?
- * return:
- * boolean.
+/** Indicate whether a character is printable.
+ * @param[in] ch Character to check for printability.
+ * @return Non-zero if the character is printable; zero if it is not.
*/
static int
printable(int ch)
return(ch > 0x20 && ch < 0x7f);
}
+/** Decode a bitstring label from DNS.
+ * @param[in,out] cpp Pointer to start of label.
+ * @param[in,out] dn Output buffer.
+ * @param[in] eom End of message.
+ */
static int
irc_decode_bitstring(const char **cpp, char *dn, const char *eom)
{
return(dn - beg);
}
-/*
- * irc_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.
+/** Convert an ASCII name string into an encoded domain name.
+ * This function enforces per-label and total name lengths.
+ * @param[in] src ASCII name string.
+ * @param[out] dst Destination buffer.
+ * @param[in] dstsiz Number of bytes that can be written to \a dst.
+ * @return -1 on failure, 0 if \a src was not fully qualified, 1 if \a
+ * src was fully qualified.
*/
int
irc_ns_name_pton(const char *src, unsigned char *dst, size_t dstsiz)
return (0);
}
-/*
- * irc_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.
+/** Compress a domain name.
+ * @param[in] src List of length-prefixed labels.
+ * @param[out] dst Output buffer.
+ * @param[in] dstsiz Number of bytes that can be written to \a dst.
+ * @param[in,out] dnptrs Array of pointers to previously compressed names.
+ * @param[in] lastdnptr End of \a dnptrs array.
+ * @return Number of bytes written to \a dst.
*/
int
irc_ns_name_pack(const unsigned char *src, unsigned char *dst, int dstsiz,
return(dstp - dst);
}
+/** Encode and compress an ASCII domain name.
+ * @param[in] src ASCII domain name.
+ * @param[out] dst Output buffer.
+ * @param[in] dstsiz Number of bytes that can be written to \a dst.
+ * @param[in] dnptrs Array of previously compressed names.
+ * @param[in] lastdnptr End of \a dnptrs array.
+ */
static int
irc_ns_name_compress(const char *src, unsigned char *dst, size_t dstsiz,
const unsigned char **dnptrs, const unsigned char **lastdnptr)
return(irc_ns_name_pack(tmp, dst, dstsiz, dnptrs, lastdnptr));
}
+/** Encode a bitstring label.
+ * @param[in,out] bp Input buffer pointer.
+ * @param[in] end End of input buffer.
+ * @param[out] labelp Pointer to output label.
+ * @param[out] dst Output buffer.
+ * @param[out] eom End of output buffer.
+ */
static int
irc_encode_bitsring(const char **bp, const char *end, unsigned char **labelp,
unsigned char **dst, const char *eom)
if (beg_blen == NULL) {
if (c == '0') {
- /* blen never begings with 0 */
+ /* blen never begins with 0 */
return(EINVAL);
}
beg_blen = cp;
return(0);
}
-/*
- * 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.
+/** Find a name in an array of compressed name.
+ * @param[in] domain Name to search for.
+ * @param[in] msg Start of DNS message.
+ * @param[in] dnptrs Start of compressed name array.
+ * @param[in] lastdnptr End of compressed name array.
+ * @return Non-negative offset from \a msg, or -1 if not found.
*/
static int
irc_dn_find(const unsigned char *domain, const unsigned char *msg,
return (-1);
}
-/*
- * Thinking in noninternationalized USASCII (per the DNS spec),
- * convert this character to lower case if it's upper case.
+/** Convert a character to lowercase, assuming ASCII encoded English.
+ * @param[in] ch Character to convert.
+ * @return Lower-case version of \a ch.
*/
static int
-mklower(int ch)
+mklower(int ch)
{
if (ch >= 0x41 && ch <= 0x5A)
return(ch + 0x20);
/* From resolv/mkquery.c */
-/*
- * Form all types of queries.
- * Returns the size of the result or -1.
+/** Form a query for \a dname in \a buf.
+ * @param[in] dname Domain name to look up.
+ * @param[in] class Query class to set in header.
+ * @param[in] type Query type to set in header.
+ * @param[out] buf Output buffer for query.
+ * @param[in] buflen Number of bytes that can be written to \a buf.
+ * @return Length of message written to \a buf, or -1 on error.
*/
int
irc_res_mkquery(
projects / ircu2.10.12-pk.git / blobdiff