From c146b5840bbd7ad89c8a8de6192590ad0595a977 Mon Sep 17 00:00:00 2001

From: Benjamin Marzinski <bmarzins@redhat.com>

Date: Thu, 7 Apr 2016 18:19:58 -0500

Subject: [PATCH] Add libmpathcmd library and use it internally

Other programs would like to communicate with multipathd to issue

command or check status.  Instead of having them exec multipathd,

I've pulled the code that sends commands and receives replies from

multipathd into its own library.  I've made the multipath tools use

this library internally as well.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>

---

 Makefile                         |    1 

 Makefile.inc                     |    2 

 libmpathcmd/Makefile             |   32 +++++++

 libmpathcmd/mpath_cmd.c          |  178 +++++++++++++++++++++++++++++++++++++++

 libmpathcmd/mpath_cmd.h          |  125 +++++++++++++++++++++++++++

 libmpathpersist/Makefile         |    5 -

 libmpathpersist/mpath_updatepr.c |   30 +++---

 libmultipath/Makefile            |    4 

 libmultipath/config.c            |    1 

 libmultipath/configure.c         |   10 +-

 libmultipath/uxsock.c            |   88 +++----------------

 libmultipath/uxsock.h            |    6 -

 mpathpersist/Makefile            |    2 

 multipath/Makefile               |    5 -

 multipathd/Makefile              |    4 

 multipathd/uxclnt.c              |   13 +-

 multipathd/uxlsnr.c              |    9 -

 17 files changed, 401 insertions(+), 114 deletions(-)

 create mode 100644 libmpathcmd/Makefile

 create mode 100644 libmpathcmd/mpath_cmd.c

 create mode 100644 libmpathcmd/mpath_cmd.h

Index: multipath-tools-130222/Makefile

===================================================================

--- multipath-tools-130222.orig/Makefile

+++ multipath-tools-130222/Makefile

@@ -20,6 +20,7 @@ export KRNLSRC

 export KRNLOBJ

 BUILDDIRS = \

+	libmpathcmd \

 	libmultipath \

 	libmultipath/prioritizers \

 	libmultipath/checkers \

Index: multipath-tools-130222/Makefile.inc

===================================================================

--- multipath-tools-130222.orig/Makefile.inc

+++ multipath-tools-130222/Makefile.inc

@@ -34,6 +34,8 @@ syslibdir   = $(prefix)/usr/$(LIB)

 libdir	    = $(prefix)/usr/$(LIB)/multipath

 unitdir     = $(prefix)/lib/systemd/system

 mpathpersistdir = $(TOPDIR)/libmpathpersist

+includedir  = $(prefix)/usr/include

+mpathcmddir = $(TOPDIR)/libmpathcmd

 GZIP        = /bin/gzip -9 -c

 INSTALL_PROGRAM = install

Index: multipath-tools-130222/libmpathcmd/Makefile

===================================================================

--- /dev/null

+++ multipath-tools-130222/libmpathcmd/Makefile

@@ -0,0 +1,32 @@

+# Makefile

+#

+include ../Makefile.inc

+

+SONAME=0

+DEVLIB = libmpathcmd.so

+LIBS = $(DEVLIB).$(SONAME)

+

+CFLAGS += -fPIC

+

+OBJS = mpath_cmd.o

+

+all: $(LIBS)

+

+$(LIBS): $(OBJS)

+	$(CC) $(LDFLAGS) $(SHARED_FLAGS) -Wl,-soname=$@ $(CFLAGS) -o $@ $(OBJS) $(LIBDEPS)

+	ln -sf $@ $(DEVLIB)

+

+install: $(LIBS)

+	$(INSTALL_PROGRAM) -d $(DESTDIR)$(syslibdir)

+	$(INSTALL_PROGRAM) -m 755 $(LIBS) $(DESTDIR)$(syslibdir)/$(LIBS)

+	ln -sf $(LIBS) $(DESTDIR)$(syslibdir)/$(DEVLIB)

+	$(INSTALL_PROGRAM) -d $(DESTDIR)$(includedir)

+	$(INSTALL_PROGRAM) -m 644 mpath_cmd.h $(DESTDIR)$(includedir)

+

+uninstall:

+	rm -f $(DESTDIR)$(syslibdir)/$(LIBS)

+	rm -f $(DESTDIR)$(syslibdir)/$(DEVLIB)

+	rm -f $(DESTDIR)$(includedir)/mpath_cmd.h

+

+clean:

+	rm -f core *.a *.o *.gz *.so *.so.*

Index: multipath-tools-130222/libmpathcmd/mpath_cmd.c

===================================================================

--- /dev/null

+++ multipath-tools-130222/libmpathcmd/mpath_cmd.c

@@ -0,0 +1,178 @@

+#include <stdlib.h>

+#include <unistd.h>

+#include <stdio.h>

+#include <sys/types.h>

+#include <sys/socket.h>

+#include <sys/un.h>

+#include <poll.h>

+#include <string.h>

+#include <errno.h>

+

+#include "mpath_cmd.h"

+

+/*

+ * keep reading until its all read

+ */

+static ssize_t read_all(int fd, void *buf, size_t len, unsigned int timeout)

+{

+	size_t total = 0;

+	ssize_t n;

+	int ret;

+	struct pollfd pfd;

+

+	while (len) {

+		pfd.fd = fd;

+		pfd.events = POLLIN;

+		ret = poll(&pfd, 1, timeout);

+		if (!ret) {

+			errno = ETIMEDOUT;

+			return -1;

+		} else if (ret < 0) {

+			if (errno == EINTR)

+				continue;

+			return -1;

+		} else if (!(pfd.revents & POLLIN))

+			continue;

+		n = read(fd, buf, len);

+		if (n < 0) {

+			if ((errno == EINTR) || (errno == EAGAIN))

+				continue;

+			return -1;

+		}

+		if (!n)

+			return total;

+		buf = n + (char *)buf;

+		len -= n;

+		total += n;

+	}

+	return total;

+}

+

+/*

+ * keep writing until it's all sent

+ */

+static size_t write_all(int fd, const void *buf, size_t len)

+{

+	size_t total = 0;

+

+	while (len) {

+		ssize_t n = write(fd, buf, len);

+		if (n < 0) {

+			if ((errno == EINTR) || (errno == EAGAIN))

+				continue;

+			return total;

+		}

+		if (!n)

+			return total;

+		buf = n + (char *)buf;

+		len -= n;

+		total += n;

+	}

+	return total;

+}

+

+/*

+ * connect to a unix domain socket

+ */

+int mpath_connect(void)

+{

+	int fd, len;

+	struct sockaddr_un addr;

+

+	memset(&addr, 0, sizeof(addr));

+	addr.sun_family = AF_LOCAL;

+	addr.sun_path[0] = '\0';

+	len = strlen(DEFAULT_SOCKET) + 1 + sizeof(sa_family_t);

+	strncpy(&addr.sun_path[1], DEFAULT_SOCKET, len);

+

+	fd = socket(AF_LOCAL, SOCK_STREAM, 0);

+	if (fd == -1)

+		return -1;

+

+	if (connect(fd, (struct sockaddr *)&addr, len) == -1) {

+		close(fd);

+		return -1;

+	}

+

+	return fd;

+}

+

+int mpath_disconnect(int fd)

+{

+	return close(fd);

+}

+

+ssize_t mpath_recv_reply_len(int fd, unsigned int timeout)

+{

+	size_t len;

+	ssize_t ret;

+

+	ret = read_all(fd, &len, sizeof(len), timeout);

+	if (ret < 0)

+		return ret;

+	if (ret != sizeof(len)) {

+		errno = EIO;

+		return -1;

+	}

+	return len;

+}

+

+int mpath_recv_reply_data(int fd, char *reply, size_t len,

+			  unsigned int timeout)

+{

+	ssize_t ret;

+

+	ret = read_all(fd, reply, len, timeout);

+	if (ret < 0)

+		return ret;

+	if (ret != len) {

+		errno = EIO;

+		return -1;

+	}

+	reply[len - 1] = '\0';

+	return 0;

+}

+

+int mpath_recv_reply(int fd, char **reply, unsigned int timeout)

+{

+	int err;

+	ssize_t len;

+

+	*reply = NULL;

+	len = mpath_recv_reply_len(fd, timeout);

+	if (len <= 0)

+		return -1;

+	*reply = malloc(len);

+	if (!*reply)

+		return -1;

+	err = mpath_recv_reply_data(fd, *reply, len, timeout);

+	if (err) {

+		free(*reply);

+		*reply = NULL;

+		return -1;

+	}

+	return 0;

+}

+

+int mpath_send_cmd(int fd, const char *cmd)

+{

+	size_t len;

+

+	if (cmd != NULL)

+		len = strlen(cmd) + 1;

+	else

+		len = 0;

+	if (write_all(fd, &len, sizeof(len)) != sizeof(len))

+		return -1;

+	if (len && write_all(fd, cmd, len) != len)

+		return -1;

+	return 0;

+}

+

+int mpath_process_cmd(int fd, const char *cmd, char **reply,

+		      unsigned int timeout)

+{

+	if (mpath_send_cmd(fd, cmd) != 0)

+		return -1;

+	return mpath_recv_reply(fd, reply, timeout);

+}

Index: multipath-tools-130222/libmpathcmd/mpath_cmd.h

===================================================================

--- /dev/null

+++ multipath-tools-130222/libmpathcmd/mpath_cmd.h

@@ -0,0 +1,125 @@

+/*

+ * Copyright (C) 2015 Red Hat, Inc.

+ *

+ * This file is part of the device-mapper multipath userspace tools.

+ *

+ * This program is free software; you can redistribute it and/or

+ * modify it under the terms of the GNU Lesser General Public License

+ * as published by the Free Software Foundation; either version 2

+ * of the License, or (at your option) any later version.

+ *

+ * This program 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 Lesser General Public License for more details.

+ *

+ * You should have received a copy of the GNU Lesser General Public

+ * License along with this program; if not, write to the Free Software

+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,

+ * USA.

+ */

+

+#ifndef LIB_MPATH_CMD_H

+#define LIB_MPATH_CMD_H

+

+#ifdef __cpluscplus

+extern "C" {

+#endif

+

+#define DEFAULT_SOCKET		"/org/kernel/linux/storage/multipathd"

+#define DEFAULT_REPLY_TIMEOUT	10000

+

+

+/*

+ * DESCRIPTION:

+ * 	Connect to the running multipathd daemon. On systems with the

+ * 	multipathd.socket systemd unit file installed, this command will

+ * 	start multipathd if it is not already running. This function

+ * 	must be run before any of the others in this library

+ *

+ * RETURNS:

+ * 	A file descriptor on success. -1 on failure (with errno set).

+ */

+int mpath_connect(void);

+

+

+/*

+ * DESCRIPTION:

+ * 	Disconnect from the multipathd daemon. This function must be

+ * 	run after after processing all the multipath commands.

+ *

+ * RETURNS:

+ * 	0 on success. -1 on failure (with errno set).

+ */

+int mpath_disconnect(int fd);

+

+

+/*

+ * DESCRIPTION

+ * 	Send multipathd a command and return the reply. This function

+ * 	does the same as calling mpath_send_cmd() and then

+ *	mpath_recv_reply()

+ *

+ * RETURNS:

+ * 	0 on successs, and reply will either be NULL (if there was no

+ * 	reply data), or point to the reply string, which must be freed by

+ * 	the caller. -1 on failure (with errno set).

+ */

+int mpath_process_cmd(int fd, const char *cmd, char **reply,

+		      unsigned int timeout);

+

+

+/*

+ * DESCRIPTION:

+ * 	Send a command to multipathd

+ *

+ * RETURNS:

+ * 	0 on success. -1 on failure (with errno set)

+ */

+int mpath_send_cmd(int fd, const char *cmd);

+

+

+/*

+ * DESCRIPTION:

+ * 	Return a reply from multipathd for a previously sent command.

+ * 	This is equivalent to calling mpath_recv_reply_len(), allocating

+ * 	a buffer of the appropriate size, and then calling

+ *	mpath_recv_reply_data() with that buffer.

+ *

+ * RETURNS:

+ * 	0 on success, and reply will either be NULL (if there was no

+ * 	reply data), or point to the reply string, which must be freed by

+ * 	the caller, -1 on failure (with errno set).

+ */

+int mpath_recv_reply(int fd, char **reply, unsigned int timeout);

+

+

+/*

+ * DESCRIPTION:

+ * 	Return the size of the upcoming reply data from the sent multipath

+ * 	command. This must be called before calling mpath_recv_reply_data().

+ *

+ * RETURNS:

+ * 	The required size of the reply data buffer on success. -1 on

+ * 	failure (with errno set).

+ */

+ssize_t mpath_recv_reply_len(int fd, unsigned int timeout);

+

+

+/*

+ * DESCRIPTION:

+ * 	Return the reply data from the sent multipath command.

+ * 	mpath_recv_reply_len must be called first. reply must point to a

+ * 	buffer of len size.

+ *

+ * RETURNS:

+ * 	0 on success, and reply will contain the reply data string. -1

+ * 	on failure (with errno set).

+ */

+int mpath_recv_reply_data(int fd, char *reply, size_t len,

+			  unsigned int timeout);

+

+#ifdef __cplusplus

+}

+#endif

+#endif /* LIB_MPATH_CMD_H */

Index: multipath-tools-130222/libmpathpersist/Makefile

===================================================================

--- multipath-tools-130222.orig/libmpathpersist/Makefile

+++ multipath-tools-130222/libmpathpersist/Makefile

@@ -10,8 +10,9 @@ DEVLIB = libmpathpersist.so

 LIBS = $(DEVLIB).$(SONAME)

-CFLAGS += -fPIC -I$(multipathdir) -I$(mpathpersistdir)

-LIBDEPS +=  -lpthread -ldevmapper -ldl -L$(multipathdir) -lmultipath

+CFLAGS += -fPIC -I$(multipathdir) -I$(mpathpersistdir) -I$(mpathcmddir)

+LIBDEPS +=  -lpthread -ldevmapper -ldl -L$(multipathdir) -lmultipath \

+	-L$(mpathcmddir) -lmpathcmd

 OBJS = mpath_persist.o mpath_updatepr.o mpath_pr_ioctl.o 

Index: multipath-tools-130222/libmpathpersist/mpath_updatepr.c

===================================================================

--- multipath-tools-130222.orig/libmpathpersist/mpath_updatepr.c

+++ multipath-tools-130222/libmpathpersist/mpath_updatepr.c

@@ -12,9 +12,9 @@

 #include <sys/poll.h>

 #include <errno.h>

 #include <debug.h>

+#include <mpath_cmd.h>

+#include <uxsock.h>

 #include "memory.h"

-#include "../libmultipath/uxsock.h"

-#include "../libmultipath/defaults.h"

 unsigned long mem_allocated;    /* Total memory used in Bytes */

@@ -23,10 +23,9 @@ int update_prflag(char * arg1, char * ar

 	int fd;

 	char str[64];

 	char *reply;

-	size_t len;

 	int ret = 0;

-	fd = ux_socket_connect(DEFAULT_SOCKET);

+	fd = mpath_connect();

 	if (fd == -1) {

 		condlog (0, "ux socket connect error");

 		return 1 ;

@@ -34,18 +33,23 @@ int update_prflag(char * arg1, char * ar

 	snprintf(str,sizeof(str),"map %s %s", arg1, arg2);

 	condlog (2, "%s: pr flag message=%s", arg1, str);

-	send_packet(fd, str, strlen(str) + 1);

-	recv_packet(fd, &reply, &len;;

-

-	condlog (2, "%s: message=%s reply=%s", arg1, str, reply);

-	if (!reply || strncmp(reply,"ok", 2) == 0)

-		ret = -1;

-	else if (strncmp(reply, "fail", 4) == 0)

+	send_packet(fd, str);

+	ret = recv_packet(fd, &reply);

+	if (ret < 0) {

+		condlog(2, "%s: message=%s recv error=%d", arg1, str, errno);

 		ret = -2;

-	else{

-		ret = atoi(reply);

+	} else {

+		condlog (2, "%s: message=%s reply=%s", arg1, str, reply);

+		if (!reply || strncmp(reply,"ok", 2) == 0)

+			ret = -1;

+		else if (strncmp(reply, "fail", 4) == 0)

+			ret = -2;

+		else{

+			ret = atoi(reply);

+		}

 	}

 	free(reply);

+	mpath_disconnect(fd);

 	return ret;

 }

Index: multipath-tools-130222/libmultipath/Makefile

===================================================================

--- multipath-tools-130222.orig/libmultipath/Makefile

+++ multipath-tools-130222/libmultipath/Makefile

@@ -7,8 +7,8 @@ include ../Makefile.inc

 SONAME=0

 DEVLIB = libmultipath.so

 LIBS = $(DEVLIB).$(SONAME)

-LIBDEPS = -lpthread -ldl -ldevmapper -ludev

-CFLAGS += -fPIC

+LIBDEPS = -lpthread -ldl -ldevmapper -ludev -L$(mpathcmddir) -lmpathcmd

+CFLAGS += -fPIC -I$(mpathcmddir)

 OBJS = memory.o parser.o vector.o devmapper.o \

        hwtable.o blacklist.o util.o dmparser.o config.o \

Index: multipath-tools-130222/libmultipath/config.c

===================================================================

--- multipath-tools-130222.orig/libmultipath/config.c

+++ multipath-tools-130222/libmultipath/config.c

@@ -25,6 +25,7 @@

 #include "prio.h"

 #include "devmapper.h"

 #include "version.h"

+#include "mpath_cmd.h"

 static int

 hwe_strmatch (struct hwentry *hwe1, struct hwentry *hwe2)

Index: multipath-tools-130222/libmultipath/configure.c

===================================================================

--- multipath-tools-130222.orig/libmultipath/configure.c

+++ multipath-tools-130222/libmultipath/configure.c

@@ -14,6 +14,7 @@

 #include <errno.h>

 #include <libdevmapper.h>

 #include <libudev.h>

+#include <mpath_cmd.h>

 #include "checkers.h"

 #include "vector.h"

@@ -752,16 +753,15 @@ check_daemon(void)

 {

 	int fd;

 	char *reply;

-	size_t len;

 	int ret = 0;

-	fd = ux_socket_connect(DEFAULT_SOCKET);

+	fd = mpath_connect();

 	if (fd == -1)

 		return 0;

-	if (send_packet(fd, "show daemon", 12) != 0)

+	if (send_packet(fd, "show daemon") != 0)

 		goto out;

-	if (recv_packet(fd, &reply, &len) != 0)

+	if (recv_packet(fd, &reply) != 0)

 		goto out;

 	if (strstr(reply, "shutdown"))

@@ -772,7 +772,7 @@ check_daemon(void)

 out_free:

 	FREE(reply);

 out:

-	close(fd);

+	mpath_disconnect(fd);

 	return ret;

 }

Index: multipath-tools-130222/libmultipath/uxsock.c

===================================================================

--- multipath-tools-130222.orig/libmultipath/uxsock.c

+++ multipath-tools-130222/libmultipath/uxsock.c

@@ -16,37 +16,10 @@

 #include <sys/poll.h>

 #include <signal.h>

 #include <errno.h>

+#include <mpath_cmd.h>

 #include "memory.h"

 #include "uxsock.h"

-

-/*

- * connect to a unix domain socket

- */

-int ux_socket_connect(const char *name)

-{

-	int fd, len;

-	struct sockaddr_un addr;

-

-	memset(&addr, 0, sizeof(addr));

-	addr.sun_family = AF_LOCAL;

-	addr.sun_path[0] = '\0';

-	len = strlen(name) + 1 + sizeof(sa_family_t);

-	strncpy(&addr.sun_path[1], name, len);

-

-	fd = socket(AF_LOCAL, SOCK_STREAM, 0);

-	if (fd == -1) {

-		return -1;

-	}

-

-	if (connect(fd, (struct sockaddr *)&addr, len) == -1) {

-		close(fd);

-		return -1;

-	}

-

-	return fd;

-}

-

 /*

  * create a unix domain socket and start listening on it

  * return a file descriptor open on the socket

@@ -102,32 +75,9 @@ size_t write_all(int fd, const void *buf

 }

 /*

- * keep reading until its all read

- */

-size_t read_all(int fd, void *buf, size_t len)

-{

-	size_t total = 0;

-

-	while (len) {

-		ssize_t n = read(fd, buf, len);

-		if (n < 0) {

-			if ((errno == EINTR) || (errno == EAGAIN))

-				continue;

-			return total;

-		}

-		if (!n)

-			return total;

-		buf = n + (char *)buf;

-		len -= n;

-		total += n;

-	}

-	return total;

-}

-

-/*

  * send a packet in length prefix format

  */

-int send_packet(int fd, const char *buf, size_t len)

+int send_packet(int fd, const char *buf)

 {

 	int ret = 0;

 	sigset_t set, old;

@@ -137,10 +87,7 @@ int send_packet(int fd, const char *buf,

 	sigaddset(&set, SIGPIPE);

 	pthread_sigmask(SIG_BLOCK, &set, &old;;

-	if (write_all(fd, &len, sizeof(len)) != sizeof(len))

-		ret = -1;

-	if (!ret && write_all(fd, buf, len) != len)

-		ret = -1;

+	ret = mpath_send_cmd(fd, buf);

 	/* And unblock it again */

 	pthread_sigmask(SIG_SETMASK, &old, NULL);

@@ -151,25 +98,24 @@ int send_packet(int fd, const char *buf,

 /*

  * receive a packet in length prefix format

  */

-int recv_packet(int fd, char **buf, size_t *len)

+int recv_packet(int fd, char **buf)

 {

-	if (read_all(fd, len, sizeof(*len)) != sizeof(*len)) {

-		(*buf) = NULL;

-		*len = 0;

-		return -1;

-	}

-	if (len == 0) {

-		(*buf) = NULL;

-		return 0;

-	}

-	(*buf) = MALLOC(*len);

+	int err;

+	ssize_t len;

+	unsigned int timeout = DEFAULT_REPLY_TIMEOUT;

+

+	*buf = NULL;

+	len = mpath_recv_reply_len(fd, timeout);

+	if (len <= 0)

+		return len;

+	(*buf) = MALLOC(len);

 	if (!*buf)

-		return -1;

-	if (read_all(fd, *buf, *len) != *len) {

+		return -ENOMEM;

+	err = mpath_recv_reply_data(fd, *buf, len, timeout);

+	if (err) {

 		FREE(*buf);

 		(*buf) = NULL;

-		*len = 0;

-		return -1;

+		return err;

 	}

 	return 0;

 }

Index: multipath-tools-130222/libmultipath/uxsock.h

===================================================================

--- multipath-tools-130222.orig/libmultipath/uxsock.h

+++ multipath-tools-130222/libmultipath/uxsock.h

@@ -1,7 +1,5 @@

 /* some prototypes */

-int ux_socket_connect(const char *name);

 int ux_socket_listen(const char *name);

-int send_packet(int fd, const char *buf, size_t len);

-int recv_packet(int fd, char **buf, size_t *len);

+int send_packet(int fd, const char *buf);

+int recv_packet(int fd, char **buf);

 size_t write_all(int fd, const void *buf, size_t len);

-size_t read_all(int fd, void *buf, size_t len);

Index: multipath-tools-130222/mpathpersist/Makefile

===================================================================

--- multipath-tools-130222.orig/mpathpersist/Makefile

+++ multipath-tools-130222/mpathpersist/Makefile

@@ -5,7 +5,7 @@ include ../Makefile.inc

 OBJS = main.o 

 CFLAGS += -I$(multipathdir) -I$(mpathpersistdir) 

-LDFLAGS += -lpthread -ldevmapper -L$(mpathpersistdir) -lmpathpersist -L$(multipathdir) -lmultipath -ludev

+LDFLAGS += -lpthread -ldevmapper -L$(mpathpersistdir) -lmpathpersist -L$(multipathdir) -L$(mpathcmddir) -lmpathcmd -lmultipath -ludev

 EXEC = mpathpersist

Index: multipath-tools-130222/multipath/Makefile

===================================================================

--- multipath-tools-130222.orig/multipath/Makefile

+++ multipath-tools-130222/multipath/Makefile

@@ -6,8 +6,9 @@ include ../Makefile.inc

 OBJS = main.o

-CFLAGS += -fPIC -I$(multipathdir)