-/*
- * include/ircd_res.h for referencing functions in ircd/ircd_res.c
- *
- * $Id$
+/** @file
+ * @brief IRC resolver API.
+ * @version $Id$
*/
#ifndef INCLUDED_res_h
struct StatDesc;
/* Here we define some values lifted from nameser.h */
-#define NS_NOTIFY_OP 4
-#define NS_INT16SZ 2
-#define NS_IN6ADDRSZ 16
-#define NS_INADDRSZ 4
-#define NS_INT32SZ 4
-#define NS_CMPRSFLGS 0xc0
-#define NS_MAXCDNAME 255
-#define QUERY 0
-#define IQUERY 1
-#define NO_ERRORS 0
-#define SERVFAIL 2
-#define T_A 1
-#define T_AAAA 28
-#define T_PTR 12
-#define T_CNAME 5
-#define T_NULL 10
-#define C_IN 1
-#define QFIXEDSZ 4
-#define RRFIXEDSZ 10
-#define HFIXEDSZ 12
-
+#define NS_INT16SZ 2 /**< Size of a 16-bit value. */
+#define NS_INT32SZ 4 /**< Size of a 32-bit value. */
+#define NS_CMPRSFLGS 0xc0 /**< Prefix flags that indicate special types */
+#define NS_MAXCDNAME 255 /**< Maximum length of a compressed domain name. */
+#define QUERY 0 /**< Forward (normal) DNS query operation. */
+#define NO_ERRORS 0 /**< No errors processing a query. */
+#define SERVFAIL 2 /**< Server error while processing a query. */
+#define T_A 1 /**< Hostname -> IPv4 query type. */
+#define T_AAAA 28 /**< Hostname -> IPv6 query type. */
+#define T_PTR 12 /**< IP(v4 or v6) -> hostname query type. */
+#define T_CNAME 5 /**< Canonical name resolution query type. */
+#define C_IN 1 /**< Internet query class. */
+#define QFIXEDSZ 4 /**< Length of fixed-size part of query. */
+#define HFIXEDSZ 12 /**< Length of fixed-size DNS header. */
+
+/** Structure to store an IP address. */
struct irc_in_addr
{
- unsigned short in6_16[8];
+ unsigned short in6_16[8]; /**< IPv6 encoded parts, little-endian. */
};
+/** Structure to store an IP address and port number. */
struct irc_sockaddr
{
- struct irc_in_addr addr;
- unsigned short port;
+ struct irc_in_addr addr; /**< IP address. */
+ unsigned short port; /**< Port number, host-endian. */
};
+/** DNS reply structure. */
struct DNSReply
{
- char *h_name;
- int h_addrtype;
- struct irc_in_addr addr;
+ char *h_name; /**< Hostname. */
+ struct irc_in_addr addr; /**< IP address. */
};
+/** DNS callback structure. */
struct DNSQuery
{
- void *vptr; /* pointer used by callback to identify request */
- void (*callback)(void* vptr, struct DNSReply *reply); /* callback to call */
+ void *vptr; /**< pointer used by callback to identify request */
+ void (*callback)(void* vptr, struct DNSReply *reply); /**< callback to call */
};
+/** DNS query and response header. */
typedef struct
{
- unsigned id :16; /* query identification number */
+ unsigned id :16; /**< query identification number */
#ifdef WORDS_BIGENDIAN
/* fields in third byte */
- unsigned qr: 1; /* response flag */
- unsigned opcode: 4; /* purpose of message */
- unsigned aa: 1; /* authoritive answer */
- unsigned tc: 1; /* truncated message */
- unsigned rd: 1; /* recursion desired */
+ unsigned qr: 1; /**< response flag */
+ unsigned opcode: 4; /**< purpose of message */
+ unsigned aa: 1; /**< authoritive answer */
+ unsigned tc: 1; /**< truncated message */
+ unsigned rd: 1; /**< recursion desired */
/* fields in fourth byte */
- unsigned ra: 1; /* recursion available */
- unsigned unused :1; /* unused bits (MBZ as of 4.9.3a3) */
- unsigned ad: 1; /* authentic data from named */
- unsigned cd: 1; /* checking disabled by resolver */
- unsigned rcode :4; /* response code */
+ unsigned ra: 1; /**< recursion available */
+ unsigned unused :1; /**< unused bits (MBZ as of 4.9.3a3) */
+ unsigned ad: 1; /**< authentic data from named */
+ unsigned cd: 1; /**< checking disabled by resolver */
+ unsigned rcode :4; /**< response code */
#else
/* fields in third byte */
- unsigned rd :1; /* recursion desired */
- unsigned tc :1; /* truncated message */
- unsigned aa :1; /* authoritive answer */
- unsigned opcode :4; /* purpose of message */
- unsigned qr :1; /* response flag */
+ unsigned rd :1; /**< recursion desired */
+ unsigned tc :1; /**< truncated message */
+ unsigned aa :1; /**< authoritive answer */
+ unsigned opcode :4; /**< purpose of message */
+ unsigned qr :1; /**< response flag */
/* fields in fourth byte */
- unsigned rcode :4; /* response code */
- unsigned cd: 1; /* checking disabled by resolver */
- unsigned ad: 1; /* authentic data from named */
- unsigned unused :1; /* unused bits (MBZ as of 4.9.3a3) */
- unsigned ra :1; /* recursion available */
+ unsigned rcode :4; /**< response code */
+ unsigned cd: 1; /**< checking disabled by resolver */
+ unsigned ad: 1; /**< authentic data from named */
+ unsigned unused :1; /**< unused bits (MBZ as of 4.9.3a3) */
+ unsigned ra :1; /**< recursion available */
#endif
/* remaining bytes */
- unsigned qdcount :16; /* number of question entries */
- unsigned ancount :16; /* number of answer entries */
- unsigned nscount :16; /* number of authority entries */
- unsigned arcount :16; /* number of resource entries */
+ unsigned qdcount :16; /**< number of question entries */
+ unsigned ancount :16; /**< number of answer entries */
+ unsigned nscount :16; /**< number of authority entries */
+ unsigned arcount :16; /**< number of resource entries */
} HEADER;
extern int init_resolver(void);
* The authors takes no responsibility for any damage or loss
* of property which results from the use of this software.
*
- * $Id$
- *
* July 1999 - Rewrote a bunch of stuff here. Change hostent builder code,
* added callbacks and reference counting of returned hostents.
* --Bleep (Thomas Helvey <tomh@inxpress.net>)
*
* Apr 28, 2003 --cryogen and Dianora
*/
+/** @file
+ * @brief IRC resolver functions.
+ * @version $Id$
+ */
#include "client.h"
#include "ircd_alloc.h"
#error this code needs to be able to address individual octets
#endif
+/** Resolver UDP socket. */
static struct Socket res_socket;
+/** Next DNS lookup timeout. */
static struct Timer res_timeout;
-#define MAXPACKET 1024 /* rfc sez 512 but we expand names so ... */
-#define RES_MAXALIASES 35 /* maximum aliases allowed */
-#define RES_MAXADDRS 35 /* maximum addresses allowed */
-#define AR_TTL 600 /* TTL in seconds for dns cache entries */
+/** Maximum DNS packet length.
+ * RFC says 512, but we add extra for expanded names.
+ */
+#define MAXPACKET 1024
+#define AR_TTL 600 /**< TTL in seconds for dns cache entries */
/* RFC 1104/1105 wasn't very helpful about what these fields
* should be named, so for now, we'll just name them this way.
* we probably should look at what named calls them or something.
*/
+/** Size of TYPE field of a DNS RR header. */
#define TYPE_SIZE (size_t)2
+/** Size of CLASS field of a DNS RR header. */
#define CLASS_SIZE (size_t)2
+/** Size of TTL field of a DNS RR header. */
#define TTL_SIZE (size_t)4
+/** Size of RDLENGTH field of a DNS RR header. */
#define RDLENGTH_SIZE (size_t)2
+/** Size of fixed-format part of a DNS RR header. */
#define ANSWER_FIXED_SIZE (TYPE_SIZE + CLASS_SIZE + TTL_SIZE + RDLENGTH_SIZE)
-typedef enum
+/** Current request state. */
+typedef enum
{
- REQ_IDLE, /* We're doing not much at all */
- REQ_PTR, /* Looking up a PTR */
- REQ_A, /* Looking up an A, possibly because AAAA failed */
- REQ_AAAA, /* Looking up an AAAA */
- REQ_CNAME, /* We got a CNAME in response, we better get a real answer next */
- REQ_INT /* ip6.arpa failed, falling back to ip6.int */
+ REQ_IDLE, /**< We're doing not much at all. */
+ REQ_PTR, /**< Looking up a PTR. */
+ REQ_A, /**< Looking up an A, possibly because AAAA failed. */
+ REQ_AAAA, /**< Looking up an AAAA. */
+ REQ_CNAME, /**< We got a CNAME in response, we better get a real answer next. */
+ REQ_INT /**< ip6.arpa failed, falling back to ip6.int. */
} request_state;
+/** Doubly linked list node. */
struct dlink
{
- struct dlink *prev;
- struct dlink *next;
+ struct dlink *prev; /**< Previous element in list. */
+ struct dlink *next; /**< Next element in list. */
};
+/** A single resolver request.
+ * (Do not be fooled by the "list" in the name.)
+ */
struct reslist
{
- struct dlink node;
- int id;
- int sent; /* number of requests sent */
- request_state state; /* State the resolver machine is in */
- time_t ttl;
- char type;
- char retries; /* retry counter */
- char sends; /* number of sends (>1 means resent) */
- char resend; /* send flag. 0 == dont resend */
- time_t sentat;
- time_t timeout;
- struct irc_in_addr addr;
- char *name;
- struct DNSQuery query; /* query callback for this request */
+ struct dlink node; /**< Doubly linked list node. */
+ int id; /**< Request ID (from request header). */
+ int sent; /**< Number of requests sent. */
+ request_state state; /**< State the resolver machine is in. */
+ char type; /**< Current request type. */
+ char retries; /**< Retry counter. */
+ char sends; /**< Number of sends (>1 means resent). */
+ char resend; /**< Send flag; 0 == dont resend. */
+ time_t sentat; /**< Timestamp we last sent this request. */
+ time_t timeout; /**< When this request times out. */
+ struct irc_in_addr addr; /**< Address for this request. */
+ char *name; /**< Hostname for this request. */
+ struct DNSQuery query; /**< Query callback for this request. */
};
+/** Base of request list. */
static struct dlink request_list;
static void rem_request(struct reslist *request);
extern int irc_nscount;
extern char irc_domain[HOSTLEN];
-/*
- * int
- * res_ourserver(inp)
- * looks up "inp" in irc_nsaddr_list[]
- * returns:
- * 0 : not found
- * >0 : found
- * author:
- * paul vixie, 29may94
- * revised for ircd, cryogen(stu) may03
+/** Check whether \a inp is a nameserver we use.
+ * @param[in] inp Nameserver address.
+ * @return Non-zero if we trust \a inp; zero if not.
*/
static int
res_ourserver(const struct irc_sockaddr *inp)
return(0);
}
-/*
- * start_resolver - do everything we need to read the resolv.conf file
- * and initialize the resolver file descriptor if needed
+/** Start (or re-start) resolver.
+ * This means read resolv.conf, initialize the list of pending
+ * requests, open the resolver socket and initialize its timeout.
*/
-static void
-start_resolver(void)
+void
+restart_resolver(void)
{
irc_res_init();
}
}
-/*
- * init_resolver - initialize resolver and resolver library
+/** Initialize resolver.
+ * This seends the pseudo-random number generator and calls
+ * restart_resolver().
+ * @return Resolver socket file descriptor.
*/
int
init_resolver(void)
{
srand(CurrentTime);
- start_resolver();
+ restart_resolver();
return(s_fd(&res_socket));
}
-/*
- * restart_resolver - reread resolv.conf, reopen socket
- */
-void
-restart_resolver(void)
-{
- start_resolver();
-}
-
-/*
- * add_local_domain - Add the domain to hostname, if it is missing
- * (as suggested by eps@TOASTER.SFSU.EDU)
+/** Append local domain to hostname if needed.
+ * If \a hname does not contain any '.'s, append #irc_domain to it.
+ * @param[in,out] hname Hostname to check.
+ * @param[in] size Length of \a hname buffer.
*/
void
add_local_domain(char* hname, size_t size)
}
}
-/*
- * add_dlink - add a link to a doubly linked list
+/** Add a node to a doubly linked list.
+ * @param[in,out] node Node to add to list.
+ * @param[in,out] next Add \a node before this one.
*/
static void
add_dlink(struct dlink *node, struct dlink *next)
node->next->prev = node;
}
-/*
- * rem_request - remove a request from the list.
- * This must also free any memory that has been allocated for
- * temporary storage of DNS results.
+/** Remove a request from the list and free it.
+ * @param[in] request Node to free.
*/
static void
rem_request(struct reslist *request)
MyFree(request);
}
-/*
- * make_request - Create a DNS request record for the server.
+/** Create a DNS request record for the server.
+ * @param[in] query Callback information for caller.
+ * @return Newly allocated and linked-in reslist.
*/
static struct reslist *
make_request(const struct DNSQuery* query)
request = (struct reslist *)MyMalloc(sizeof(struct reslist));
memset(request, 0, sizeof(struct reslist));
+ request->state = REQ_IDLE;
request->sentat = CurrentTime;
request->retries = feature_int(FEAT_IRCD_RES_RETRIES);
request->resend = 1;
request->timeout = feature_int(FEAT_IRCD_RES_TIMEOUT);
memset(&request->addr, 0, sizeof(request->addr));
- request->query.vptr = query->vptr;
- request->query.callback = query->callback;
- request->state = REQ_IDLE;
+ memcpy(&request->query, query, sizeof(request->query));
add_dlink(&request->node, &request_list);
return(request);
}
-/*
- * check_resolver_timeout - Make sure that a timeout event will
- * happen by the given time.
+/** Make sure that a timeout event will happen by the given time.
+ * @param[in] when Latest time for timeout to run.
*/
static void
check_resolver_timeout(time_t when)
timer_chg(&res_timeout, TT_ABSOLUTE, when);
}
-/*
- * timeout_resolver - Remove queries from the list which have been
- * there too long without being resolved.
+/** Drop pending DNS lookups which have timed out.
+ * @param[in] notused Timer event data (ignored).
*/
static void
timeout_resolver(struct Event *notused)
check_resolver_timeout(next_time);
}
-/*
- * delete_resolver_queries - cleanup outstanding queries
- * for which there no longer exist clients or conf lines.
+/** Drop queries that are associated with a particular pointer.
+ * This is used to clean up lookups for clients or conf blocks
+ * that went away.
+ * @param[in] vptr User callback pointer to search for.
*/
void
delete_resolver_queries(const void *vptr)
}
}
-/*
- * send_res_msg - sends msg to all nameservers found in the "_res" structure.
- * This should reflect /etc/resolv.conf. We will get responses
- * which arent needed but is easier than checking to see if nameserver
- * isnt present. Returns number of messages successfully sent to
- * nameservers or -1 if no successful sends.
+/** Send a message to all of our nameservers.
+ * @param[in] msg Message to send.
+ * @param[in] len Length of message.
+ * @param[in] rcount Maximum number of servers to ask.
+ * @return Number of servers that were successfully asked.
*/
static int
send_res_msg(const char *msg, int len, int rcount)
return(sent);
}
-/*
- * find_id - find a dns request id (id is determined by dn_mkquery)
+/** Find a DNS request by ID.
+ * @param[in] id Identifier to find.
+ * @return Matching DNS request, or NULL if none are found.
*/
static struct reslist *
find_id(int id)
return(NULL);
}
-/*
- * gethost_byname - wrapper for _type - send T_AAAA first
+/** Try to look up address for a hostname, trying IPv6 (T_AAAA) first.
+ * @param[in] name Hostname to look up.
+ * @param[in] query Callback information.
*/
void
gethost_byname(const char *name, const struct DNSQuery *query)
do_query_name(query, name, NULL, T_AAAA);
}
-/*
- * gethost_byaddr - get host name from address
+/** Try to look up hostname for an address.
+ * @param[in] addr Address to look up.
+ * @param[in] query Callback information.
*/
void
gethost_byaddr(const struct irc_in_addr *addr, const struct DNSQuery *query)
do_query_number(query, addr, NULL);
}
-/*
- * do_query_name - nameserver lookup name
+/** Send a query to look up the address for a name.
+ * @param[in] query Callback information.
+ * @param[in] name Hostname to look up.
+ * @param[in] request DNS lookup structure (may be NULL).
+ * @param[in] type Preferred request type.
*/
static void
do_query_name(const struct DNSQuery *query, const char *name,
if (request == NULL)
{
request = make_request(query);
- request->name = (char *)MyMalloc(strlen(host_name) + 1);
- request->type = type;
- strcpy(request->name, host_name);
+ DupString(request->name, host_name);
#ifdef IPV6
if (type != T_A)
request->state = REQ_AAAA;
query_name(host_name, C_IN, type, request);
}
-/*
- * do_query_number - Use this to do reverse IP# lookups.
+/** Send a query to look up the name for an address.
+ * @param[in] query Callback information.
+ * @param[in] addr Address to look up.
+ * @param[in] request DNS lookup structure (may be NULL).
*/
static void
do_query_number(const struct DNSQuery *query, const struct irc_in_addr *addr,
query_name(ipbuf, C_IN, T_PTR, request);
}
-/*
- * query_name - generate a query based on class, type and name.
+/** Generate a query based on class, type and name.
+ * @param[in] name Domain name to look up.
+ * @param[in] query_class Query class (see RFC 1035).
+ * @param[in] type Query type (see RFC 1035).
+ * @param[in] request DNS request structure.
*/
static void
query_name(const char *name, int query_class, int type,
}
}
+/** Send a failed DNS lookup request again.
+ * @param[in] request Request to resend.
+ */
static void
resend_query(struct reslist *request)
{
}
}
-/*
- * proc_answer - process name server reply
+/** Process the answer for a lookup request.
+ * @param[in] request DNS request that got an answer.
+ * @param[in] header Header of DNS response.
+ * @param[in] buf DNS response body.
+ * @param[in] eob Pointer to end of DNS response.
+ * @return Number of answers read from \a buf.
*/
static int
proc_answer(struct reslist *request, HEADER* header, char* buf, char* eob)
query_class = irc_ns_get16(current);
current += CLASS_SIZE;
- request->ttl = irc_ns_get32(current);
current += TTL_SIZE;
rd_length = irc_ns_get16(current);
return(1);
}
-/*
- * res_readreply - read a dns reply from the nameserver and process it.
+/** Read a DNS reply from the nameserver and process it.
+ * @param[in] ev I/O activity event for resolver socket.
*/
static void
res_readreply(struct Event *ev)
}
}
+/** Build a DNSReply for a completed request.
+ * @param[in] request Completed DNS request.
+ * @return Newly allocated DNSReply containing host name and address.
+ */
static struct DNSReply *
make_dnsreply(struct reslist *request)
{
return(cp);
}
+/** Statistics callback to list DNS servers.
+ * @param[in] source_p Client requesting statistics.
+ * @param[in] sd Stats descriptor for request (ignored).
+ * @param[in] param Extra parameter from user (ignored).
+ */
void
report_dns_servers(struct Client *source_p, const struct StatDesc *sd, char *param)
{
}
}
+/** Report memory usage to a client.
+ * @param[in] sptr Client requesting information.
+ * @return Total memory used by pending requests.
+ */
size_t
cres_mem(struct Client* sptr)
{
return request_mem;
}
+/** Check whether an address looks valid.
+ * This means not all 0s and not all 1s.
+ * @param[in] addr Address to check for validity.
+ * @return Non-zero if the address looks valid.
+ */
int irc_in_addr_valid(const struct irc_in_addr *addr)
{
unsigned int ii;
return 0;
}
+/** Compare two IP addresses.
+ * @param[in] a First address to compare.
+ * @param[in] b Second address to compare.
+ * @return Non-zero if the two addresses differ, zero if they are identical.
+ */
int irc_in_addr_cmp(const struct irc_in_addr *a, const struct irc_in_addr *b)
{
if (irc_in_addr_is_ipv4(a))
return memcmp(a, b, sizeof(*a));
}
+/** Indicate whether an IP address is a loopback address.
+ * @param[in] addr Address to check.
+ * @return Non-zero if the address is loopback; zero if not.
+ */
int irc_in_addr_is_loopback(const struct irc_in_addr *addr)
{
if (addr->in6_16[0] != 0
projects / ircu2.10.12-pk.git / commitdiff