Allow an alternate to rad_send_request() for programs that

don't wish to wait for the RADIUS server to respond.
Reviewed by: jdp

4 files changed, 224 insertions, 137 deletions

diff --git a/lib/libradius/libradius.3 b/lib/libradius/libradius.3
index 21e65b8..d62922e 100644
--- a/lib/libradius/libradius.3
+++ b/lib/libradius/libradius.3
@@ -39,6 +39,8 @@
 .Ft int
 .Fn rad_config "struct rad_handle *h" "const char *file"
 .Ft int
+.Fn rad_continue_send_request "struct rad_handle *h" "int selected" "int *fd" "struct timeval *tv"
+.Ft int
 .Fn rad_create_request "struct rad_handle *h" "int code"
 .Ft struct in_addr
 .Fn rad_cvt_addr "const void *data"
@@ -48,6 +50,8 @@
 .Fn rad_cvt_string "const void *data" "size_t len"
 .Ft int
 .Fn rad_get_attr "struct rad_handle *h" "const void **data" "size_t *len"
+.Ft int
+.Fn rad_init_send_request "struct rad_handle *h" "int *fd" "struct timeval *tv"
 .Ft struct rad_handle *
 .Fn rad_open "void"
 .Ft int
@@ -179,10 +183,16 @@ The
 .Fn rad_put_X
 functions return 0 on success, or -1 if an error occurs.
 .Sh SENDING THE REQUEST AND RECEIVING THE RESPONSE
-After the RADIUS request has been constructed, it is sent by means
-of
-.Fn rad_send_request .
-This function sends the request and waits for a valid reply,
+After the RADIUS request has been constructed, it is sent either by means of
+.Fn rad_send_request
+or by a combination of calls to
+.Fn rad_init_send_request
+and
+.Fn rad_continue_send_request .
+.Pp
+The
+.Fn rad_send_request
+function sends the request and waits for a valid reply,
 retrying the defined servers in round-robin fashion as necessary.
 If a valid response is received,
 .Fn rad_send_request
@@ -196,9 +206,43 @@ If no valid response is received,
 .Fn rad_send_request
 returns -1.
 .Pp
+As an alternative, if you do not wish to block waiting for a response,
+.Fn rad_init_send_request
+and
+.Fn rad_continue_send_request
+may be used instead.  If a reply is received from the RADIUS server or a
+timeout occurs, these functions return a value as described for
+.Fn rad_send_request .
+Otherwise, a value of zero is returned and the values pointed to by
+.Ar fd
+and
+.Ar tv
+are set to the descriptor and timeout that should be passed to
+.Xr select 2 .
+.Pp
+.Fn rad_init_send_request
+must be called first, followed by repeated calls to
+.Fn rad_continue_send_request
+as long as a return value of zero is given.
+Between each call, the application should call
+.Xr select 2 ,
+passing
+.Ar *fd
+as a read descriptor and timing out after the interval specified by
+.Ar tv .
+When select returns,
+.Fn rad_continue_send_request
+should be called with
+.Ar selected
+set to a non-zero value if
+.Xr select 2
+indicated that the descriptor is readable.
+.Pp
 Like RADIUS requests, each response may contain zero or more
 attributes.  After a response has been received successfully by
-.Fn rad_send_request ,
+.Fn rad_send_request
+or
+.Fn rad_continue_send_request ,
 its attributes can be extracted one by one using
 .Fn rad_get_attr .
 Each time
@@ -286,6 +330,10 @@ which can be retrieved using
 .It
 .Fn rad_put_string
 .It
+.Fn rad_init_send_request
+.It
+.Fn rad_continue_send_request
+.It
 .Fn rad_send_request
 .El
 .Pp
diff --git a/lib/libradius/radlib.c b/lib/libradius/radlib.c
index 4537373..a58aa63 100644
--- a/lib/libradius/radlib.c
+++ b/lib/libradius/radlib.c
@@ -362,8 +362,6 @@ rad_config(struct rad_handle *h, const char *path)
 
 		if (rad_add_server(h, host, port, secret, timeout, maxtries) ==
 		    -1) {
-			char msg[ERRSIZE];
-
 			strcpy(msg, h->errmsg);
 			generr(h, "%s:%d: %s", path, linenum, msg);
 			retval = -1;
@@ -376,6 +374,78 @@ rad_config(struct rad_handle *h, const char *path)
 	return retval;
 }
 
+/*
+ * rad_init_send_request() must have previously been called.
+ * Returns:
+ *   0     The application should select on *fd with a timeout of tv before
+ *         calling rad_continue_send_request again.
+ *   < 0   Failure
+ *   > 0   Success
+ */
+int
+rad_continue_send_request(struct rad_handle *h, int selected, int *fd,
+                          struct timeval *tv)
+{
+	int n;
+
+	if (selected) {
+		struct sockaddr_in from;
+		int fromlen;
+
+		fromlen = sizeof from;
+		h->resp_len = recvfrom(h->fd, h->response,
+		    MSGSIZE, MSG_WAITALL, (struct sockaddr *)&from, &fromlen);
+		if (h->resp_len == -1) {
+			generr(h, "recvfrom: %s", strerror(errno));
+			return -1;
+		}
+		if (is_valid_response(h, h->srv, &from)) {
+			h->resp_len = h->response[POS_LENGTH] << 8 |
+			    h->response[POS_LENGTH+1];
+			h->resp_pos = POS_ATTRS;
+			return h->response[POS_CODE];
+		}
+	}
+
+	if (h->try == h->total_tries) {
+		generr(h, "No valid RADIUS responses received");
+		return -1;
+	}
+
+	/*
+         * Scan round-robin to the next server that has some
+         * tries left.  There is guaranteed to be one, or we
+         * would have exited this loop by now.
+	 */
+	while (h->servers[h->srv].num_tries >= h->servers[h->srv].max_tries)
+		if (++h->srv >= h->num_servers)
+			h->srv = 0;
+
+	/* Insert the scrambled password into the request */
+	if (h->pass_pos != 0)
+		insert_scrambled_password(h, h->srv);
+
+	/* Send the request */
+	n = sendto(h->fd, h->request, h->req_len, 0,
+	    (const struct sockaddr *)&h->servers[h->srv].addr,
+	    sizeof h->servers[h->srv].addr);
+	if (n != h->req_len) {
+		if (n == -1)
+			generr(h, "sendto: %s", strerror(errno));
+		else
+			generr(h, "sendto: short write");
+		return -1;
+	}
+
+	h->try++;
+	h->servers[h->srv].num_tries++;
+	tv->tv_sec = h->servers[h->srv].timeout;
+	tv->tv_usec = 0;
+	*fd = h->fd;
+
+	return 0;
+}
+
 int
 rad_create_request(struct rad_handle *h, int code)
 {
@@ -453,6 +523,69 @@ rad_get_attr(struct rad_handle *h, const void **value, size_t *len)
 }
 
 /*
+ * Returns -1 on error, 0 to indicate no event and >0 for success
+ */
+int
+rad_init_send_request(struct rad_handle *h, int *fd, struct timeval *tv)
+{
+	int srv;
+
+	/* Make sure we have a socket to use */
+	if (h->fd == -1) {
+		struct sockaddr_in sin;
+
+		if ((h->fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1) {
+			generr(h, "Cannot create socket: %s", strerror(errno));
+			return -1;
+		}
+		memset(&sin, 0, sizeof sin);
+		sin.sin_len = sizeof sin;
+		sin.sin_family = AF_INET;
+		sin.sin_addr.s_addr = INADDR_ANY;
+		sin.sin_port = htons(0);
+		if (bind(h->fd, (const struct sockaddr *)&sin,
+		    sizeof sin) == -1) {
+			generr(h, "bind: %s", strerror(errno));
+			close(h->fd);
+			h->fd = -1;
+			return -1;
+		}
+	}
+
+	/* Make sure the user gave us a password */
+	if (h->pass_pos == 0 && !h->chap_pass) {
+		generr(h, "No User or Chap Password attributes given");
+		return -1;
+	}
+	if (h->pass_pos != 0 && h->chap_pass) {
+		generr(h, "Both User and Chap Password attributes given");
+		return -1;
+	}
+
+	/* Fill in the length field in the message */
+	h->request[POS_LENGTH] = h->req_len >> 8;
+	h->request[POS_LENGTH+1] = h->req_len;
+
+	/*
+	 * Count the total number of tries we will make, and zero the
+	 * counter for each server.
+	 */
+	h->total_tries = 0;
+	for (srv = 0;  srv < h->num_servers;  srv++) {
+		h->total_tries += h->servers[srv].max_tries;
+		h->servers[srv].num_tries = 0;
+	}
+	if (h->total_tries == 0) {
+		generr(h, "No RADIUS servers specified");
+		return -1;
+	}
+
+	h->try = h->srv = 0;
+
+	return rad_continue_send_request(h, 0, fd, tv);
+}
+
+/*
  * Create and initialize a rad_handle structure, and return it to the
  * caller.  Can fail only if the necessary memory cannot be allocated.
  * In that case, it returns NULL.
@@ -520,151 +653,49 @@ rad_put_string(struct rad_handle *h, int type, const char *str)
 int
 rad_send_request(struct rad_handle *h)
 {
-	int total_tries;
-	int try;
-	int srv;
+	struct timeval timelimit;
+	struct timeval tv;
+	int fd;
 	int n;
-	int got_valid_response;
-
-	/* Make sure we have a socket to use */
-	if (h->fd == -1) {
-		struct sockaddr_in sin;
 
-		if ((h->fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1) {
-			generr(h, "Cannot create socket: %s", strerror(errno));
-			return -1;
-		}
-		memset(&sin, 0, sizeof sin);
-		sin.sin_len = sizeof sin;
-		sin.sin_family = AF_INET;
-		sin.sin_addr.s_addr = INADDR_ANY;
-		sin.sin_port = htons(0);
-		if (bind(h->fd, (const struct sockaddr *)&sin,
-		    sizeof sin) == -1) {
-			generr(h, "bind: %s", strerror(errno));
-			close(h->fd);
-			h->fd = -1;
-			return -1;
-		}
-	}
+	n = rad_init_send_request(h, &fd, &tv);
 
-	/* Make sure the user gave us a password */
-	if (h->pass_pos == 0 && !h->chap_pass) {
-		generr(h, "No User or Chap Password attributes given");
-		return -1;
-	}
+	if (n != 0)
+		return n;
 
-	if (h->pass_pos != 0 && h->chap_pass) {
-		generr(h, "Both User and Chap Password attributes given");
-		return -1;
-	}
+	gettimeofday(&timelimit, NULL);
+	timeradd(&tv, &timelimit, &timelimit);
 
-	/* Fill in the length field in the message */
-	h->request[POS_LENGTH] = h->req_len >> 8;
-	h->request[POS_LENGTH+1] = h->req_len;
+	for ( ; ; ) {
+		fd_set readfds;
 
-	/*
-	 * Count the total number of tries we will make, and zero the
-	 * counter for each server.
-	 */
-	total_tries = 0;
-	for (srv = 0;  srv < h->num_servers;  srv++) {
-		total_tries += h->servers[srv].max_tries;
-		h->servers[srv].num_tries = 0;
-	}
-	if (total_tries == 0) {
-		generr(h, "No RADIUS servers specified");
-		return -1;
-	}
+		FD_ZERO(&readfds);
+		FD_SET(fd, &readfds);
 
-	srv = 0;
-	got_valid_response = 0;
-	for (try = 0;  try < total_tries;  try++) {
-		struct timeval timelimit;
-		struct timeval tv;
+		n = select(fd + 1, &readfds, NULL, NULL, &tv);
 
-		/*
-                 * Scan round-robin to the next server that has some
-                 * tries left.  There is guaranteed to be one, or we
-                 * would have exited this loop by now.
-		 */
-		while (h->servers[srv].num_tries >=
-		    h->servers[srv].max_tries)
-			if (++srv >= h->num_servers)
-				srv = 0;
-
-		/* Insert the scrambled password into the request */
-		if (h->pass_pos != 0)
-			insert_scrambled_password(h, srv);
-
-		/* Send the request */
-		n = sendto(h->fd, h->request, h->req_len, 0,
-		    (const struct sockaddr *)&h->servers[srv].addr,
-		    sizeof h->servers[srv].addr);
-		if (n != h->req_len) {
-			if (n == -1)
-				generr(h, "sendto: %s", strerror(errno));
-			else
-				generr(h, "sendto: short write");
+		if (n == -1) {
+			generr(h, "select: %s", strerror(errno));
 			return -1;
 		}
-		h->servers[srv].num_tries++;
 
-		/* Wait for a valid response */
-		gettimeofday(&timelimit, NULL);
-		timelimit.tv_sec += h->servers[srv].timeout;
-
-		tv.tv_sec = h->servers[srv].timeout;
-		tv.tv_usec = 0;
-		for ( ; ; ) {
-			fd_set readfds;
-
-			FD_ZERO(&readfds);
-			FD_SET(h->fd, &readfds);
-			n = select(h->fd + 1, &readfds, NULL, NULL, &tv);
-			if (n == -1) {
-				generr(h, "select: %s", strerror(errno));
-				return -1;
-			}
-			if (n == 0)	/* Timed out */
-				break;
-			if (FD_ISSET(h->fd, &readfds)) {
-				struct sockaddr_in from;
-				int fromlen;
-
-				fromlen = sizeof from;
-				h->resp_len = recvfrom(h->fd, h->response,
-				    MSGSIZE, MSG_WAITALL,
-				    (struct sockaddr *)&from, &fromlen);
-				if (h->resp_len == -1) {
-					generr(h, "recvfrom: %s",
-					    strerror(errno));
-					return -1;
-				}
-				if (is_valid_response(h, srv, &from)) {
-					got_valid_response = 1;
-					break;
-				}
-			}
+		if (!FD_ISSET(fd, &readfds)) {
 			/* Compute a new timeout */
 			gettimeofday(&tv, NULL);
 			timersub(&timelimit, &tv, &tv);
-			if (tv.tv_sec < 0)	/* Still poll once more */
-				timerclear(&tv);
+			if (tv.tv_sec > 0 || (tv.tv_sec == 0 && tv.tv_usec > 0))
+				/* Continue the select */
+				continue;
 		}
-		if (got_valid_response)
-			break;
-		/* Advance to the next server */
-		if (++srv >= h->num_servers)
-			srv = 0;
-	}
-	if (!got_valid_response) {
-		generr(h, "No valid RADIUS responses received");
-		return -1;
+
+		n = rad_continue_send_request(h, n, &fd, &tv);
+
+		if (n != 0)
+			return n;
+
+		gettimeofday(&timelimit, NULL);
+		timeradd(&tv, &timelimit, &timelimit);
 	}
-	h->resp_len = h->response[POS_LENGTH] << 8 | h->response[POS_LENGTH+1];
-	h->resp_pos = POS_ATTRS;
-	return h->response[POS_CODE];
 }
 
 const char *
diff --git a/lib/libradius/radlib.h b/lib/libradius/radlib.h
index 146bcd5..5e0ce9f 100644
--- a/lib/libradius/radlib.h
+++ b/lib/libradius/radlib.h
@@ -99,18 +99,23 @@
 #define RAD_LOGIN_LAT_PORT		63	/* Integer */
 
 struct rad_handle;
+struct timeval;
 
 __BEGIN_DECLS
 int			 rad_add_server(struct rad_handle *,
 			    const char *, int, const char *, int, int);
 void			 rad_close(struct rad_handle *);
 int			 rad_config(struct rad_handle *, const char *);
+int			 rad_continue_send_request(struct rad_handle *, int,
+			    int *, struct timeval *);
 int			 rad_create_request(struct rad_handle *, int);
 struct in_addr		 rad_cvt_addr(const void *);
 u_int32_t		 rad_cvt_int(const void *);
 char			*rad_cvt_string(const void *, size_t);
 int			 rad_get_attr(struct rad_handle *, const void **,
 			    size_t *);
+int			 rad_init_send_request(struct rad_handle *, int *,
+			    struct timeval *);
 struct rad_handle	*rad_open(void);
 int			 rad_put_addr(struct rad_handle *, int, struct in_addr);
 int			 rad_put_attr(struct rad_handle *, int,
diff --git a/lib/libradius/radlib_private.h b/lib/libradius/radlib_private.h
index ec181f6..21ef9cb 100644
--- a/lib/libradius/radlib_private.h
+++ b/lib/libradius/radlib_private.h
@@ -74,10 +74,13 @@ struct rad_handle {
 	char		 pass[PASSSIZE];	/* Cleartext password */
 	int		 pass_len;	/* Length of cleartext password */
 	int		 pass_pos;	/* Position of scrambled password */
-	unsigned	 chap_pass : 1; /* Have we got a CHAP_PASSWORD ? */
+	char	 	 chap_pass;	/* Have we got a CHAP_PASSWORD ? */
 	unsigned char	 response[MSGSIZE];	/* Response received */
 	int		 resp_len;	/* Length of response */
 	int		 resp_pos;	/* Current position scanning attrs */
+	int		 total_tries;	/* How many requests we'll send */
+	int		 try;		/* How many requests we've sent */
+	int		 srv;		/* Server number we did last */
 };
 
 #endif