Merge branch 'drop-frames'

3ef53ace · Alessandro Rubini · d7091dd8 · 07ce9e52 · 3ef53ace · 3ef53ace
Commit 3ef53ace authored Jul 21, 2014 by Alessandro Rubini
13 changed files
--- a/arch-unix/Makefile
+++ b/arch-unix/Makefile
@@ -7,10 +7,12 @@ CFLAGS += -Itools
 OBJ-y += $A/unix-startup.o \
 	$A/main-loop.o \
 	$A/unix-io.o \
+	$A/unix-conf.o \
 	lib/cmdline.o \
 	lib/conf.o \
 	lib/libc-functions.o \
 	lib/dump-funcs.o \
+	lib/drop.o \
 	lib/div64.o

 # The user can set TIME=, but we pick unix time by default

--- a/arch-unix/main-loop.c
+++ b/arch-unix/main-loop.c
@@ -113,12 +113,19 @@ void unix_main_loop(struct pp_globals *ppg)
 						PP_MAX_FRAME_LENGTH - 4,
 						&ppi->last_rcv_time);

+				if (i == -2) {
+					continue; /* dropped */
+				}
+				if (i == -1) {
+					pp_diag(ppi, frames, 1,
+						"Receive Error %i: %s\n",
+						errno, strerror(errno));
+					continue;
+				}
 				if (i < PP_MINIMUM_LENGTH) {
 					pp_diag(ppi, frames, 1,
-						"Error or short frame: "
-						"%d < %d\n", i,
-						PP_MINIMUM_LENGTH
-					);
+						"Short frame: %d < %d\n", i,
+						PP_MINIMUM_LENGTH);
 					continue;
 				}


--- a/arch-unix/unix-conf.c
+++ b/arch-unix/unix-conf.c
+/*
+ * Copyright (C) 2014 CERN (www.cern.ch)
+ * Author: Alessandro Rubini
+ *
+ * Released according to GNU LGPL, version 2.1 or any later
+ */
+
+#include <ppsi/ppsi.h>
+
+
+static int f_rxdrop(int lineno, struct pp_globals *ppg, union pp_cfg_arg *arg)
+{
+	ppg->rxdrop = arg->i;
+	return 0;
+}
+
+static int f_txdrop(int lineno, struct pp_globals *ppg, union pp_cfg_arg *arg)
+{
+	ppg->txdrop = arg->i;
+	return 0;
+}
+
+struct pp_argline pp_arch_arglines[] = {
+	{ f_rxdrop,	"rx-drop",	ARG_INT},
+	{ f_txdrop,	"tx-drop",	ARG_INT},
+	{}
+};
--- a/arch-unix/unix-startup.c
+++ b/arch-unix/unix-startup.c
@@ -17,6 +17,7 @@
 #include <sys/stat.h>
 #include <unistd.h>
 #include <fcntl.h>
+#include <time.h>
 #include <sys/timex.h>

 #include <ppsi/ppsi.h>
@@ -34,6 +35,7 @@ int main(int argc, char **argv)
 {
 	struct pp_globals *ppg;
 	struct pp_instance *ppi;
+	unsigned long seed;
 	struct timex t;
 	int i;

@@ -103,6 +105,11 @@ int main(int argc, char **argv)

 	pp_init_globals(ppg, &__pp_default_rt_opts);

+	seed = time(NULL);
+	if (getenv("PPSI_DROP_SEED"))
+		seed = atoi(getenv("PPSI_DROP_SEED"));
+	ppsi_drop_init(ppg, seed);
+
 	unix_main_loop(ppg);
 	return 0; /* never reached */
 }
--- a/arch-wrs/Makefile
+++ b/arch-wrs/Makefile
@@ -8,10 +8,12 @@ OBJ-y += $A/wrs-startup.o \
 	$A/wrs-io.o \
 	$A/wrs-calibration.o \
 	$A/wrs-ipcserver.o \
+	arch-unix/unix-conf.o \
 	lib/cmdline.o \
 	lib/conf.o \
 	lib/libc-functions.o \
 	lib/dump-funcs.o \
+	lib/drop.o \
 	lib/div64.o

 # The user can set TIME=, but wrs is default

--- a/arch-wrs/main-loop.c
+++ b/arch-wrs/main-loop.c
@@ -151,12 +151,19 @@ void wrs_main_loop(struct pp_globals *ppg)
 						PP_MAX_FRAME_LENGTH - 4,
 						&ppi->last_rcv_time);

+				if (i == -2) {
+					continue; /* dropped */
+				}
+				if (i == -1) {
+					pp_diag(ppi, frames, 1,
+						"Receive Error %i: %s\n",
+						errno, strerror(errno));
+					continue;
+				}
 				if (i < PP_MINIMUM_LENGTH) {
 					pp_diag(ppi, frames, 1,
-						"Error or short frame: "
-						"%d < %d\n", i,
-						PP_MINIMUM_LENGTH
-					);
+						"Short frame: %d < %d\n", i,
+						PP_MINIMUM_LENGTH);
 					continue;
 				}


--- a/arch-wrs/wrs-startup.c
+++ b/arch-wrs/wrs-startup.c
@@ -64,6 +64,7 @@ int main(int argc, char **argv)
 	struct pp_globals *ppg;
 	struct pp_instance *ppi;
 	struct wr_dsport *wrp;
+	unsigned long seed;
 	struct timex t;
 	int i, hal_retries;

@@ -182,6 +183,11 @@ int main(int argc, char **argv)

 	pp_init_globals(ppg, &__pp_default_rt_opts);

+	seed = time(NULL);
+	if (getenv("PPSI_DROP_SEED"))
+		seed = atoi(getenv("PPSI_DROP_SEED"));
+	ppsi_drop_init(ppg, seed);
+
 	wrs_main_loop(ppg);
 	return 0; /* never reached */
 }
--- a/doc/ppsi-manual.in
+++ b/doc/ppsi-manual.in
@@ -35,7 +35,7 @@

 @setchapternewpage off

-@set update-month March 2014
+@set update-month July 2014
 @set release __RELEASE_GIT_ID__

 @finalout
@@ -427,11 +427,56 @@ may document the keywords, if the time allows it.
 configuration options. This applies to the priorities, intervals and
 thresholds, as well as the @i{slave-only} flag.

+@c ==========================================================================
+@node Configuring Faults
+@section Configuring Faults
+
+Configuration, for @t{arch-unix} and @t{arch-wrs}, allows to provide
+some fault injection.
+
+In particular, the program allows dropping frames, in both the TX and RX
+paths.  The configuration values state how many frames are dropped every
+1000.  Dropping is randomized, but the user can set the seed to ensure
+a repeatable dropping sequence.
+
+Dropping transmitted frames is performed by reporting success (and the
+timestamp), while no frame is actually sent.  A diagnostic message
+is generated at @t{frames} level 1, but other than than that nothing
+happens.   Actually, @t{arch-wrs} needs to actually send a frame in
+order to get a timestamp back; in this case the program modifies the
+frame, to use a wrong Ethernet type or a wrong UDP port. 
+
+Dropping received frames is performed by actually receiving (and
+timestamping), but returning a special error code to the caller.
+Again, PPSi creates a diagnostic message at @t{frames} level 1.
+
+The following configuration lines are supported:
+
+@table @code
+
+@item rx-drop <value>
+@itemx tx-drop <value>
+
+	Drop @i{value} frames every 1000 frames received or sent.
+        The randomized sequence is global.
+
+@end table
+
+The randomization see can be passed by pre-setting the environment
+variable @t{PPSI_DROP_SEED} to a decimal numeric value. For example:
+
+@smallexample
+   export PPSI_DROP_SEED=33
+@end smallexample
+
+@noindent
+before starting the daemon.
+
 @c ==========================================================================
 @node Configuring the Simulator
 @section Configuring the Simulator

-To tun the PPSi simulator you need to rely on diagnostics and specific
+To run the PPSi simulator you need to rely on diagnostics and specific
 configuration items.  The configuration items are defined in
 @i{arch-sim/sim-conf.c} and are not individually documented here at
 this point.

--- a/include/ppsi/pp-instance.h
+++ b/include/ppsi/pp-instance.h
@@ -213,6 +213,8 @@ struct pp_globals {
 	int max_links;
 	struct pp_globals_cfg cfg;

+	int rxdrop, txdrop;		/* fault injection, per thousand */
+
 	void *arch_data;		/* if arch needs it */
 	/* FIXME Here include all is common to many interfaces */
 };

--- a/include/ppsi/ppsi.h
+++ b/include/ppsi/ppsi.h
@@ -389,4 +389,9 @@ extern pp_action pp_initializing, pp_faulty, pp_disabled, pp_listening,
 /* The engine */
 extern int pp_state_machine(struct pp_instance *ppi, uint8_t *packet, int plen);

+/* Frame-drop support -- rx before tx, alphabetically */
+extern void ppsi_drop_init(struct pp_globals *ppg, unsigned long seed);
+extern int ppsi_drop_rx(void);
+extern int ppsi_drop_tx(void);
+
 #endif /* __PPSI_PPSI_H__ */
--- a/lib/drop.c
+++ b/lib/drop.c
+/*
+ * Copyright (C) 2014 CERN (www.cern.ch)
+ * Authors: Alessandro Rubini
+ *
+ * Released according to the GNU LGPL, version 2.1 or any later version.
+ */
+#include <ppsi/ppsi.h>
+
+/* Always rx before tx (alphabetic) */
+struct ppsi_drop {
+	unsigned long rxrand, txrand;
+	int rxrate, txrate;
+};
+
+static struct ppsi_drop d;
+
+static inline unsigned long drop_this(unsigned long *p, int rate)
+{
+	/* hash the value, according to the TYPE_0 rule of glibc */
+	*p = ((*p * 1103515245) + 12345) & 0x7fffffff;
+
+	return (*p % 1000) < rate;
+}
+
+void ppsi_drop_init(struct pp_globals *ppg, unsigned long seed)
+{
+	/* lazily, avoid passing globals every time */
+	d.rxrand = seed;
+	d.txrand = seed + 1;
+	d.rxrate = ppg->rxdrop;
+	d.txrate = ppg->txdrop;
+}
+
+int ppsi_drop_rx(void)
+{
+	if (d.rxrate)
+		return drop_this(&d.rxrand, d.rxrate);
+	return 0;
+}
+
+int ppsi_drop_tx(void)
+{
+	if (d.txrate)
+		return drop_this(&d.txrand, d.txrate);
+	return 0;
+}
+
--- a/time-unix/unix-socket.c
+++ b/time-unix/unix-socket.c
@@ -87,6 +87,12 @@ static int unix_recv_msg(struct pp_instance *ppi, int fd, void *pkt, int len,
 		 */
 		ppi->t_ops->get(ppi, t);
 	}
+
+	if (ppsi_drop_rx()) {
+		pp_diag(ppi, frames, 1, "Drop received frame\n");
+		return -2;
+	}
+
 	/* This is not really hw... */
 	pp_diag(ppi, time, 2, "recv stamp: %i.%09i (%s)\n",
 		(int)t->seconds, (int)t->nanoseconds, tv ? "kernel" : "user");
@@ -132,6 +138,14 @@ static int unix_net_send(struct pp_instance *ppi, void *pkt, int len,
 	struct ethhdr *hdr = pkt;
 	int ret;

+	/* To fake a network frame loss, set the timestamp and do not send */
+	if (ppsi_drop_tx()) {
+		if (t)
+			ppi->t_ops->get(ppi, t);
+		pp_diag(ppi, frames, 1, "Drop sent frame\n");
+		return len;
+	}
+
 	if (ppi->ethernet_mode) {
 		hdr->h_proto = htons(ETH_P_1588);

@@ -358,6 +372,7 @@ static int unix_net_init(struct pp_instance *ppi)
 		if (unix_open_ch(ppi, ppi->iface_name, i))
 			return -1;
 	}
+
 	return 0;
 }


--- a/time-wrs/wrs-socket.c
+++ b/time-wrs/wrs-socket.c
@@ -223,7 +223,7 @@ static int wrs_recv_msg(struct pp_instance *ppi, int fd, void *pkt, int len,
 		if (!WR_DSPOR(ppi)->wrModeOn) {
 			/* for non-wr-mode any reported stamp is correct */
 			t->correct = 1;
-			return ret;
+			goto drop;
 		}
 		if (s->dmtd_phase_valid)
 		{
@@ -233,6 +233,12 @@ static int wrs_recv_msg(struct pp_instance *ppi, int fd, void *pkt, int len,
 		}
 	}

+drop:
+	if (ppsi_drop_rx()) {
+		pp_diag(ppi, frames, 1, "Drop received frame\n");
+		return -2;
+	}
+
 	return ret;
 }

@@ -344,13 +350,22 @@ int wrs_net_send(struct pp_instance *ppi, void *pkt, int len,
 	struct sockaddr_in addr;
 	struct ethhdr *hdr = pkt;
 	struct wrs_socket *s;
-	int ret, fd;
+	int ret, fd, drop;

 	s = (struct wrs_socket *)NP(ppi)->ch[PP_NP_GEN].arch_data;

+	/*
+	 * To fake a packet loss, we must corrupt the frame; we need
+	 * to transmit it for real, if we want to get back our
+	 * hardware stamp. Thus, remember if we drop, and use this info.
+	 */
+	drop = ppsi_drop_tx();
+
 	if (ppi->ethernet_mode) {
 		fd = NP(ppi)->ch[PP_NP_GEN].fd;
 		hdr->h_proto = htons(ETH_P_1588);
+		if (drop)
+			hdr->h_proto++;

 		memcpy(hdr->h_dest, PP_MCAST_MACADDRESS, ETH_ALEN);
 		/* raw socket implementation always uses gen socket */
@@ -361,6 +376,10 @@ int wrs_net_send(struct pp_instance *ppi, void *pkt, int len,

 		ret = send(fd, hdr, len, 0);
 		poll_tx_timestamp(ppi, s, fd, t);
+
+		if (drop) /* avoid messaging about stamps that are not used */
+			goto drop_msg;
+
 		if (pp_diag_allow(ppi, frames, 2))
 			dump_1588pkt("send: ", pkt, len, t);
 		pp_diag(ppi, time, 1, "send stamp: (correct %i) %9li.%09li\n",
@@ -374,15 +393,24 @@ int wrs_net_send(struct pp_instance *ppi, void *pkt, int len,
 	addr.sin_family = AF_INET;
 	addr.sin_port = htons(chtype == PP_NP_GEN ? PP_GEN_PORT : PP_EVT_PORT);
 	addr.sin_addr.s_addr = NP(ppi)->mcast_addr;
-
+	if (drop)
+		addr.sin_port = 3200;
 	ret = sendto(fd, pkt, len, 0,
 		(struct sockaddr *)&addr, sizeof(struct sockaddr_in));
 	poll_tx_timestamp(ppi, s, fd, t);
+
+	if (drop) /* like above: skil messages about timestamps */
+		goto drop_msg;
+
 	if (pp_diag_allow(ppi, frames, 2))
 		dump_payloadpkt("send: ", pkt, len, t);
 	pp_diag(ppi, time, 1, "send stamp: (correct %i) %9li.%09li\n",
 		t->correct, (long)t->seconds,
 		(long)t->nanoseconds);
+drop_msg:
+	if (drop)
+		pp_diag(ppi, frames, 1, "Drop sent frame\n");
+
 	return ret;
 }