+/* -*-c-*-
+ *
+ * $Id: ident.c,v 1.1 1999/10/04 21:41:58 mdw Exp $
+ *
+ * Nonblocking RFC931 client
+ *
+ * (c) 1999 Mark Wooding
+ */
+
+/*----- Licensing notice --------------------------------------------------*
+ *
+ * This file is part of the mLib utilities library.
+ *
+ * mLib is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * mLib is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with mLib; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+/*----- Revision history --------------------------------------------------*
+ *
+ * $Log: ident.c,v $
+ * Revision 1.1 1999/10/04 21:41:58 mdw
+ * Added ident client from `fw'.
+ *
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+
+#include "conn.h"
+#include "dstr.h"
+#include "exc.h"
+#include "ident.h"
+#include "selbuf.h"
+
+/*----- Main code ---------------------------------------------------------*/
+
+/* --- @next@ --- *
+ *
+ * Arguments: @char **pp@ = address of string pointer
+ *
+ * Returns: Address of next token.
+ *
+ * Use: Reads the next token from the result string. Tokens are
+ * terminated by whitespace, or `:' or `,' characters. The
+ * result string has had `\' escapes removed; it's stored in
+ * the same memory as the input string. The actual content
+ * of the delimiter doesn't seem to be interesting, so it
+ * gets thrown away.
+ */
+
+static char *next(char **pp)
+{
+ char *p, *q, *r;
+
+ /* --- Deal with reads past the end of the string --- */
+
+ if (!*pp)
+ return ("");
+
+ /* --- Initialize various pointers into the string --- */
+
+ p = q = r = *pp;
+
+ /* --- Skip past any leading whitespace --- */
+
+ while (isspace((unsigned char)*p))
+ p++;
+
+ /* --- Now start work on the string itself --- */
+
+ for (;;) {
+ if (*p == 0 || *p == ':' || *p == ',' || isspace((unsigned char)*p))
+ break;
+ else if (*p == '\\') {
+ p++;
+ if (!*p) {
+ *q++ = '\\';
+ break;
+ }
+ }
+ *q++ = *p++;
+ }
+
+ /* --- Tidy up afterwards --- */
+
+ while (isspace((unsigned char)*p))
+ p++;
+ if (*p == 0)
+ *pp = 0;
+ else if (*p == ':' || *p == ',')
+ *pp = p + 1;
+ else
+ *pp = p;
+ *q = 0;
+
+ return (r);
+}
+
+/* --- @parse@ --- *
+ *
+ * Arguments: @char *p@ = pointer to input string from identd
+ * @ident_reply *i@ = pointer to output block
+ *
+ * Returns: ---
+ *
+ * Use: Parses a result string from an RFC931 (identd) server.
+ */
+
+static void parse(char *p, ident_reply *i)
+{
+ char *q;
+
+ /* --- Read the source and destination port numbers --- */
+
+ i->sport = atoi(next(&p));
+ i->dport = atoi(next(&p));
+
+ /* --- Find out what sort of a reply this is --- */
+
+ q = next(&p);
+ if (strcmp(q, "USERID") == 0) {
+ i->type = IDENT_USERID;
+ i->u.userid.os = next(&p);
+ i->u.userid.user = next(&p);
+ } else if (strcmp(q, "ERROR") == 0) {
+ i->type = IDENT_ERROR;
+ i->u.error = next(&p);
+ } else
+ i->type = IDENT_BAD;
+}
+
+/* --- @line@ --- *
+ *
+ * Arguments: @char *s@ = pointer to string from ident server
+ * @void *p@ = pointer to my request block
+ *
+ * Returns: ---
+ *
+ * Use: Handles a string from an ident server.
+ */
+
+static void line(char *s, void *p)
+{
+ ident_request *rq = p;
+
+ rq->state = IDENT_DONE;
+ selbuf_disable(&rq->b);
+ close(rq->b.reader.fd);
+ if (!s)
+ rq->func(0, rq->p);
+ else {
+ ident_reply i;
+ parse(s, &i);
+ rq->func(&i, rq->p);
+ }
+}
+
+/* --- @connected@ --- *
+ *
+ * Arguments: @int fd@ = file descriptor
+ * @void *p@ = pointer to request block
+ *
+ * Returns: ---
+ *
+ * Use: Handles a connection to a remote ident server.
+ */
+
+static void connected(int fd, void *p)
+{
+ ident_request *rq = p;
+ dstr d = DSTR_INIT;
+
+ /* --- Handle an error during the connect --- */
+
+ if (fd < 0)
+ goto fail_0;
+
+ /* --- Initialize the string to send to the remote host --- */
+
+ TRY {
+ dstr_putf(&d, "%u, %u\r\n",
+ ntohs(rq->remote.sin_port), ntohs(rq->local.sin_port));
+ } CATCH switch (exc_type) {
+ case EXC_NOMEM:
+ EXIT_TRY;
+ goto fail_1;
+ default:
+ RETHROW;
+ } END_TRY;
+
+ /* --- Do the rest of the work --- */
+
+ if (write(fd, d.buf, d.len) < d.len)
+ goto fail_1;
+ dstr_destroy(&d);
+ rq->state = IDENT_READ;
+ selbuf_init(&rq->b, rq->s, fd, line, rq);
+ return;
+
+ /* --- Tidy up after misfortunes --- */
+
+fail_1:
+ dstr_destroy(&d);
+ close(fd);
+fail_0:
+ rq->state = IDENT_DONE;
+ rq->func(0, rq->p);
+}
+
+/* --- @ident_abort@ --- *
+ *
+ * Arguments: @ident_request *rq@ = pointer to request block
+ *
+ * Returns: ---
+ *
+ * Use: Cancels an ident request in progress.
+ */
+
+void ident_abort(ident_request *rq)
+{
+ switch (rq->state) {
+ case IDENT_CONN:
+ conn_kill(&rq->c);
+ break;
+ case IDENT_READ:
+ selbuf_disable(&rq->b);
+ close(rq->b.reader.fd);
+ break;
+ }
+}
+
+/* --- @go@ --- *
+ *
+ * Arguments: @ident_request *rq@ = pointer to request block
+ *
+ * Returns: ---
+ *
+ * Use: Starts a connection to the remote ident server.
+ */
+
+static void go(ident_request *rq)
+{
+ int fd;
+ struct sockaddr_in sin;
+ int opt;
+
+ /* --- Create the socket I'll use --- */
+
+ if ((fd = socket(PF_INET, SOCK_STREAM, 0)) < 0)
+ goto fail_0;
+ memset(&sin, 0, sizeof(sin));
+ sin.sin_family = AF_INET;
+ sin.sin_port = 0;
+ sin.sin_addr = rq->local.sin_addr;
+ if (bind(fd, (struct sockaddr *)&sin, sizeof(sin)))
+ goto fail_1;
+
+ /* --- Out-of-band data would confuse us --- */
+
+ opt = 1;
+ setsockopt(fd, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(opt));
+
+ /* --- Start a connection to the remote server --- */
+
+ sin.sin_family = AF_INET;
+ sin.sin_port = htons(113);
+ sin.sin_addr = rq->remote.sin_addr;
+ conn_init(&rq->c, rq->s, fd, (struct sockaddr *)&sin, sizeof(sin),
+ connected, rq);
+
+ /* --- Finish off initializing the block --- */
+
+ rq->state = IDENT_CONN;
+ return;
+
+ /* --- Tidy up after lossage --- */
+
+fail_1:
+ close(fd);
+fail_0:
+ rq->state = IDENT_DONE;
+ rq->func(0, rq->p);
+}
+
+/* --- @ident@ --- *
+ *
+ * Arguments: @ident_request *rq@ = pointer to request block
+ * @sel_state *s@ = I/O multiplexor
+ * @const struct sockaddr_in *local, *remote@ = addresses
+ * @void (*func)(ident_reply *i, void *p)@ = handler function
+ * @void *p@ = argument for handler
+ *
+ * Returns: ---
+ *
+ * Use: Initializes an ident request.
+ */
+
+void ident(ident_request *rq, sel_state *s,
+ const struct sockaddr_in *local,
+ const struct sockaddr_in *remote,
+ void (*func)(ident_reply */*i*/, void */*p*/),
+ void *p)
+{
+ memcpy(&rq->local, local, sizeof(rq->local));
+ memcpy(&rq->remote, remote, sizeof(rq->remote));
+ rq->func = func;
+ rq->p = p;
+ rq->s = s;
+ go(rq);
+}
+
+/* --- @ident_socket@ --- *
+ *
+ * Arguments: @ident_request *rq@ = pointer to request block
+ * @sel_state *s@ = I/O multiplexor
+ * @int sk@ = connected socket file descriptor
+ * @void (*func)(ident_reply *i, void *p)@ = handler function
+ * @void *p@ = argument for handler
+ *
+ * Returns: ---
+ *
+ * Use: An alternative interface to @ident@. Initializes an ident
+ * request from a connected socket, rather than from an explicit
+ * address. This will call @getsockname@ and @getpeername@ to
+ * find out what the socket is actually connected to, which adds
+ * convenience but wastes time.
+ */
+
+void ident_socket(ident_request *rq, sel_state *s, int sk,
+ void (*func)(ident_reply */*i*/, void */*p*/),
+ void *p)
+{
+ int sinsz;
+ if ((sinsz = sizeof(struct sockaddr_in),
+ getsockname(sk, (struct sockaddr *)&rq->local, &sinsz)) ||
+ (sinsz = sizeof(struct sockaddr_in),
+ getpeername(sk, (struct sockaddr *)&rq->remote, &sinsz))) {
+ rq->state = IDENT_DONE;
+ func(0, p);
+ return;
+ }
+
+ rq->func = func;
+ rq->p = p;
+ rq->s = s;
+ go(rq);
+}
+
+/*----- That's all, folks -------------------------------------------------*/
~mdw / mLib / commitdiff