return of the accept filter part II

accept filters are now loadable as well as able to be compiled into
the kernel.

two accept filters are provided, one that returns sockets when data
arrives the other when an http request is completed (doesn't work
with 0.9 requests)

Reviewed by: jmg

1 files changed, 183 insertions, 0 deletions

diff --git a/sys/netinet/accf_http.c b/sys/netinet/accf_http.c
new file mode 100644
index 0000000..09a4e9f
--- /dev/null
+++ b/sys/netinet/accf_http.c
@@ -0,0 +1,183 @@
+/*-
+ * Copyright (c) 2000 Alfred Perlstein <alfred@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	$FreeBSD$
+ */
+
+#define ACCEPT_FILTER_MOD
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/sysproto.h>
+#include <sys/kernel.h>
+#include <sys/proc.h>
+#include <sys/malloc.h> 
+#include <sys/unistd.h>
+#include <sys/file.h>
+#include <sys/fcntl.h>
+#include <sys/protosw.h>
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+#include <sys/stat.h>
+#include <sys/mbuf.h>
+#include <sys/resource.h>
+#include <sys/sysent.h>
+#include <sys/resourcevar.h>
+
+/*
+ * XXX: doesn't work with 0.9 requests, make a seperate filter
+ * based on this one if you want to decode those.
+ */
+
+/* check for GET */
+static void sohashttpget(struct socket *so, void *arg, int waitflag);
+/* check for end of HTTP request */
+static void soishttpconnected(struct socket *so, void *arg, int waitflag);
+static char sbindex(struct mbuf **mp, int *begin, int end);
+
+static struct accept_filter accf_http_filter = {
+	"httpready",
+	sohashttpget,
+	NULL,
+	NULL
+};
+
+static moduledata_t accf_http_mod = {
+	"accf_http",
+	accept_filt_generic_mod_event,
+	&accf_http_filter
+};
+
+DECLARE_MODULE(accf_http, accf_http_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
+
+
+static char
+sbindex(struct mbuf **mp, int *begin, int end)
+{
+	struct mbuf *m = *mp;
+	int diff = end - *begin + 1;
+
+	while (m->m_len < diff) {
+		*begin += m->m_len;
+		diff -= m->m_len;
+		if (m->m_next) {
+			m = m->m_next;
+		} else if (m->m_nextpkt) {
+			m = m->m_nextpkt;
+		} else {
+			/* only happens if end > data in socket buffer */
+			panic("sbindex: not enough data");
+		}
+	}
+	*mp = m;
+	return *(mtod(m, char *) + diff - 1);
+}
+
+static void
+sohashttpget(struct socket *so, void *arg, int waitflag)
+{
+
+	if ((so->so_state & SS_CANTRCVMORE) == 0) {
+		struct mbuf *m;
+
+		if (so->so_rcv.sb_cc < 6)
+			return;
+		m = so->so_rcv.sb_mb;
+		if (bcmp(mtod(m, char *), "GET ", 4) == 0) {
+			soishttpconnected(so, arg, waitflag);
+			return;
+		}
+	}
+
+	so->so_upcall = NULL;
+	so->so_rcv.sb_flags &= ~SB_UPCALL;
+	soisconnected(so);
+	return;
+}
+
+static void
+soishttpconnected(struct socket *so, void *arg, int waitflag)
+{
+	char a, b, c;
+	struct mbuf *y, *z;
+
+	if ((so->so_state & SS_CANTRCVMORE) == 0) {
+		/* seek to end and keep track of next to last mbuf */
+		y = so->so_rcv.sb_mb;
+		while (y->m_nextpkt)
+			y = y->m_nextpkt;
+		z = y;	
+		while (y->m_next) {
+			z = y;
+			y = y->m_next;
+		}
+			
+		if (z->m_len + y->m_len > 2) {
+			int index = y->m_len - 1;
+
+			c = *(mtod(y, char *) + index--);
+			switch (index) {
+			case -1:
+				y = z;
+				index = y->m_len - 1;
+				b = *(mtod(y, char *) + index--);
+				break;
+			case 0:
+				b = *(mtod(y, char *) + index--);
+				y = z;
+				index = y->m_len - 1;
+				break;
+			default:
+				b = *(mtod(y, char *) + index--);
+				break;
+			}
+			a = *(mtod(y, char *) + index--);
+		} else {
+			int begin = 0;
+			int end = so->so_rcv.sb_cc - 3;
+
+			y = so->so_rcv.sb_mb;
+			a = sbindex(&y, &begin, end++);
+			b = sbindex(&y, &begin, end++);
+			c = sbindex(&y, &begin, end++);
+		}
+
+		if (c == '\n' && (b == '\n' || (b == '\r' && a == '\n'))) {
+			/* we have all request headers */
+			goto done;
+		} else {
+			/* still need more data */
+			so->so_upcall = soishttpconnected;
+			so->so_rcv.sb_flags |= SB_UPCALL;
+			return;
+		}
+	}
+
+done:
+	so->so_upcall = NULL;
+	so->so_rcv.sb_flags &= ~SB_UPCALL;
+	soisconnected(so);
+	return;
+}