Add a logging subsystem and change all DPRINTF to ISCSI_LOG

Add a mechanism where we can set a logging subsystem that libiscsi can use.
Create an example 'log to stderr' that utilities can use for convenience.

Makefile.am

@@ -26,7 +26,8 @@ lib_LTLIBRARIES = lib/libiscsi.la
 lib_libiscsi_la_SOURCES = \
 	lib/connect.c lib/crc32c.c lib/discovery.c lib/init.c \
 	lib/login.c lib/md5.c lib/nop.c lib/pdu.c lib/scsi-command.c \
-	lib/scsi-lowlevel.c lib/socket.c lib/sync.c lib/task_mgmt.c
+	lib/scsi-lowlevel.c lib/socket.c lib/sync.c lib/task_mgmt.c \
+	lib/logging.c
 
 SONAME=$(firstword $(subst ., ,$(VERSION)))
 SOREL=$(shell printf "%d%02d%02d" $(subst ., ,$(VERSION)))

include/iscsi-private.h

@@ -127,7 +127,9 @@ struct iscsi_context {
 	int lun;
 	int no_auto_reconnect;
 	int reconnect_deferred;
-	int debug;
+
+	int log_level;
+	iscsi_log_fn log_fn;
 };
 
 #define ISCSI_PDU_IMMEDIATE		       0x40
@@ -284,6 +286,16 @@ struct scsi_task *iscsi_scsi_get_task_from_pdu(struct iscsi_pdu *pdu);
 
 void iscsi_set_noautoreconnect(struct iscsi_context *iscsi, int state);
 
+#define ISCSI_LOG(iscsi, level, format, args...) \
+	do { \
+		if (level <= iscsi->log_level && iscsi->log_fn) { \
+			iscsi_log_message(iscsi, level, format, ## args); \
+		} \
+	} while (0)
+
+void
+iscsi_log_message(struct iscsi_context *iscsi, int level, const char *format, ...);
+
 #ifdef __cplusplus
 }
 #endif

include/iscsi.h

@@ -966,18 +966,6 @@ iscsi_scsi_task_cancel(struct iscsi_context *iscsi,
 EXTERN void
 iscsi_scsi_cancel_all_tasks(struct iscsi_context *iscsi);
 
-#define DPRINTF(iscsi,level,fmt,args...) \
-	do { \
-		if ((iscsi)->debug >= level) { \
-			fprintf(stderr,"libiscsi: "); \
-			fprintf(stderr, (fmt), ##args); \
-			if (iscsi->target_name[0]) { \
-				fprintf(stderr," [%s]",iscsi->target_name); \
-			} \
-			fprintf(stderr,"\n"); \
-		} \
-	} while (0);
-
 /*
  * This function is to set the debugging level where level is
  * 
@@ -987,9 +975,18 @@ iscsi_scsi_cancel_all_tasks(struct iscsi_context *iscsi);
  * 3  = user set variables
  * 4  = function calls
  * 5  = ...
+ * 10 = everything
  */
 EXTERN void
-iscsi_set_debug(struct iscsi_context *iscsi, int level);
+iscsi_set_log_level(struct iscsi_context *iscsi, int level);
+
+typedef void (*iscsi_log_fn)(int level, const char *mesage);
+
+/* Set the logging function to use */
+EXTERN void iscsi_set_log_fn(struct iscsi_context *iscsi, iscsi_log_fn fn);
+
+/* predefined log function that just writes to stderr */
+EXTERN void iscsi_log_to_stderr(int level, const char *message);
 
 /*
  * This function is to set the TCP_USER_TIMEOUT option. It has to be called after iscsi

lib/connect.c

@@ -177,7 +177,7 @@ int iscsi_reconnect(struct iscsi_context *old_iscsi)
 {
 	struct iscsi_context *iscsi = old_iscsi;
 
-	DPRINTF(iscsi,2,"reconnect initiated");
+	ISCSI_LOG(iscsi, 2, "reconnect initiated");
 
 	/* This is mainly for tests, where we do not want to automatically
 	   reconnect but rather want the commands to fail with an error
@@ -235,10 +235,10 @@ try_again:
 
 	iscsi->lun = old_iscsi->lun;
 
-	strncpy(iscsi->portal,old_iscsi->portal,MAX_STRING_SIZE);
+	strncpy(iscsi->portal,old_iscsi->portal, MAX_STRING_SIZE);
-	
-	iscsi->debug = old_iscsi->debug;
 	
+	iscsi->log_level = old_iscsi->log_level;
+	iscsi->log_fn = old_iscsi->log_fn;
 	iscsi->tcp_user_timeout = old_iscsi->tcp_user_timeout;
 	iscsi->tcp_keepidle = old_iscsi->tcp_keepidle;
 	iscsi->tcp_keepcnt = old_iscsi->tcp_keepcnt;
@@ -254,7 +254,7 @@ try_again:
 		if (backoff > 30) {
 			backoff=30;
 		}
-		DPRINTF(iscsi,1,"reconnect try %d failed, waiting %d seconds",retry,backoff);
+		ISCSI_LOG(iscsi, 1, "reconnect try %d failed, waiting %d seconds",retry,backoff);
 		iscsi_destroy_context(iscsi);
 		sleep(backoff);
 		retry++;

lib/init.c

@@ -76,7 +76,8 @@ iscsi_create_context(const char *initiator_name)
 	iscsi->tcp_keepidle=30;
 
 	if (getenv("LIBISCSI_DEBUG") != NULL) {
-		iscsi_set_debug(iscsi,atoi(getenv("LIBISCSI_DEBUG")));
+		iscsi_set_log_level(iscsi, atoi(getenv("LIBISCSI_DEBUG")));
+		iscsi_set_log_fn(iscsi, iscsi_log_to_stderr);
 	}
 
 	if (getenv("LIBISCSI_TCP_USER_TIMEOUT") != NULL) {
@@ -243,25 +244,25 @@ void
 iscsi_set_error(struct iscsi_context *iscsi, const char *error_string, ...)
 {
 	va_list ap;
-	char errstr[MAX_STRING_SIZE+1] = {0};
+	char errstr[MAX_STRING_SIZE + 1] = {0};
 
 	va_start(ap, error_string);
 	if (vsnprintf(errstr, MAX_STRING_SIZE, error_string, ap) < 0) {
-		strncpy(errstr,"could not format error string!",MAX_STRING_SIZE);
+		strncpy(errstr, "could not format error string!", MAX_STRING_SIZE);
 	}
 	va_end(ap);
 
 	if (iscsi != NULL) {
-		strncpy(iscsi->error_string,errstr,MAX_STRING_SIZE);
+		strncpy(iscsi->error_string, errstr,MAX_STRING_SIZE);
-		DPRINTF(iscsi,1,"%s",iscsi->error_string);
+		ISCSI_LOG(iscsi, 1, "%s",iscsi->error_string);
 	}
 }
 
 void
-iscsi_set_debug(struct iscsi_context *iscsi, int level)
+iscsi_set_log_level(struct iscsi_context *iscsi, int level)
 {
-	iscsi->debug = level;
+	iscsi->log_level = level;
-	DPRINTF(iscsi,2,"set debug level to %d",level);
+	ISCSI_LOG(iscsi, 2, "set log level to %d", level);
 }
 
 const char *

lib/libiscsi.def

@@ -17,6 +17,7 @@ iscsi_get_target_address
 iscsi_inquiry_sync
 iscsi_inquiry_task
 iscsi_is_logged_in
+iscsi_log_to_stderr
 iscsi_login_async
 iscsi_login_sync
 iscsi_logout_async
@@ -64,7 +65,8 @@ iscsi_scsi_command_sync
 iscsi_scsi_task_cancel
 iscsi_service
 iscsi_set_alias
-iscsi_set_debug
+iscsi_set_log_level
+iscsi_set_log_fn
 iscsi_set_header_digest
 iscsi_set_initiator_username_pwd
 iscsi_set_isid_en

lib/libiscsi.syms

@@ -15,6 +15,7 @@ iscsi_get_target_address
 iscsi_inquiry_sync
 iscsi_inquiry_task
 iscsi_is_logged_in
+iscsi_log_to_stderr
 iscsi_login_async
 iscsi_login_sync
 iscsi_logout_async
@@ -62,7 +63,8 @@ iscsi_scsi_command_sync
 iscsi_scsi_task_cancel
 iscsi_service
 iscsi_set_alias
-iscsi_set_debug
+iscsi_set_log_level
+iscsi_set_log_fn
 iscsi_set_header_digest
 iscsi_set_initiator_username_pwd
 iscsi_set_isid_en

lib/logging.c

@@ -0,0 +1,64 @@
+/*
+   Copyright (C) 2012 by Ronnie Sahlberg <ronniesahlberg@gmail.com>
+
+   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 2.1 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, see <http://www.gnu.org/licenses/>.
+*/
+
+#if defined(WIN32)
+#else
+#include <unistd.h>
+#endif
+
+#include <stdio.h>
+#include <stdarg.h>
+#include <arpa/inet.h>
+#include "iscsi.h"
+#include "iscsi-private.h"
+#include "scsi-lowlevel.h"
+
+void
+iscsi_log_to_stderr(int level, const char *message)
+{
+	fprintf(stderr, "libiscsi:%d %s\n", level, message);
+}
+
+void
+iscsi_set_log_fn(struct iscsi_context *iscsi, iscsi_log_fn fn)
+{
+	iscsi->log_fn = fn;
+}
+
+void
+iscsi_log_message(struct iscsi_context *iscsi, int level, const char *format, ...)
+{
+        va_list ap;
+	static char message[1024];
+	int ret;
+
+	if (iscsi->log_fn == NULL) {
+		return;
+	}
+
+        va_start(ap, format);
+	ret = vsnprintf(message, 1024, format, ap);
+        va_end(ap);
+
+	if (ret < 0) {
+		return;
+	}
+
+	iscsi->log_fn(level, message);
+}
+
+

lib/login.c

@@ -1075,7 +1075,7 @@ iscsi_process_login_reply(struct iscsi_context *iscsi, struct iscsi_pdu *pdu,
 	}
 
 	if (status == SCSI_STATUS_REDIRECT && iscsi->target_address) {
-		DPRINTF(iscsi,2,"target requests redirect to %s",iscsi->target_address);
+		ISCSI_LOG(iscsi, 2, "target requests redirect to %s",iscsi->target_address);
 		pdu->callback(iscsi, SCSI_STATUS_REDIRECT, NULL,
 				  pdu->private_data);
 		return 0;

lib/socket.c

@@ -86,7 +86,7 @@ int set_tcp_user_timeout(struct iscsi_context *iscsi)
 		iscsi_set_error(iscsi, "TCP: Failed to set tcp user timeout. Error %s(%d)", strerror(errno), errno);
 		return -1;
 	}
-	DPRINTF(iscsi,3,"TCP_USER_TIMEOUT set to %d",iscsi->tcp_user_timeout);
+	ISCSI_LOG(iscsi, 3, "TCP_USER_TIMEOUT set to %d",iscsi->tcp_user_timeout);
 	return 0;
 }
 
@@ -100,7 +100,7 @@ int set_tcp_syncnt(struct iscsi_context *iscsi)
 		iscsi_set_error(iscsi, "TCP: Failed to set tcp syn retries. Error %s(%d)", strerror(errno), errno);
 		return -1;
 	}
-	DPRINTF(iscsi,3,"TCP_SYNCNT set to %d",iscsi->tcp_syncnt);
+	ISCSI_LOG(iscsi, 3, "TCP_SYNCNT set to %d",iscsi->tcp_syncnt);
 	return 0;
 }
 
@@ -114,7 +114,7 @@ iscsi_connect_async(struct iscsi_context *iscsi, const char *portal,
 	struct addrinfo *ai = NULL;
 	int socksize;
 
-	DPRINTF(iscsi,2,"connecting to portal %s",portal);
+	ISCSI_LOG(iscsi, 2, "connecting to portal %s",portal);
 
 	if (iscsi->fd != -1) {
 		iscsi_set_error(iscsi,
@@ -244,8 +244,9 @@ iscsi_disconnect(struct iscsi_context *iscsi)
 
 	close(iscsi->fd);
 
-	if (iscsi->connected_portal[0])
+	if (iscsi->connected_portal[0]) {
-		DPRINTF(iscsi,2,"disconnected from portal %s",iscsi->connected_portal);
+		ISCSI_LOG(iscsi, 2, "disconnected from portal %s",iscsi->connected_portal);
+	}
 
 	iscsi->fd  = -1;
 	iscsi->is_connected = 0;
@@ -510,7 +511,7 @@ iscsi_service(struct iscsi_context *iscsi, int revents)
 			return iscsi_service_reconnect_if_loggedin(iscsi);
 		}
 
-		DPRINTF(iscsi,2,"connection to %s established",iscsi->connected_portal);
+		ISCSI_LOG(iscsi, 2, "connection to %s established",iscsi->connected_portal);
 
 		iscsi->is_connected = 1;
 		if (iscsi->socket_status_cb) {
@@ -585,31 +586,31 @@ iscsi_free_iscsi_inqueue(struct iscsi_in_pdu *inqueue)
 void iscsi_set_tcp_syncnt(struct iscsi_context *iscsi, int value)
 {
 	iscsi->tcp_syncnt=value;
-	DPRINTF(iscsi,2,"TCP_SYNCNT will be set to %d on next socket creation",value);
+	ISCSI_LOG(iscsi, 2, "TCP_SYNCNT will be set to %d on next socket creation",value);
 }
 
 void iscsi_set_tcp_user_timeout(struct iscsi_context *iscsi, int value)
 {
 	iscsi->tcp_user_timeout=value;
-	DPRINTF(iscsi,2,"TCP_USER_TIMEOUT will be set to %dms on next socket creation",value);
+	ISCSI_LOG(iscsi, 2, "TCP_USER_TIMEOUT will be set to %dms on next socket creation",value);
 }
 
 void iscsi_set_tcp_keepidle(struct iscsi_context *iscsi, int value)
 {
 	iscsi->tcp_keepidle=value;
-	DPRINTF(iscsi,2,"TCP_KEEPIDLE will be set to %d on next socket creation",value);
+	ISCSI_LOG(iscsi, 2, "TCP_KEEPIDLE will be set to %d on next socket creation",value);
 }
 
 void iscsi_set_tcp_keepcnt(struct iscsi_context *iscsi, int value)
 {
 	iscsi->tcp_keepcnt=value;
-	DPRINTF(iscsi,2,"TCP_KEEPCNT will be set to %d on next socket creation",value);
+	ISCSI_LOG(iscsi, 2, "TCP_KEEPCNT will be set to %d on next socket creation",value);
 }
 
 void iscsi_set_tcp_keepintvl(struct iscsi_context *iscsi, int value)
 {
 	iscsi->tcp_keepintvl=value;
-	DPRINTF(iscsi,2,"TCP_KEEPINTVL will be set to %d on next socket creation",value);
+	ISCSI_LOG(iscsi, 2, "TCP_KEEPINTVL will be set to %d on next socket creation",value);
 }
 
 int iscsi_set_tcp_keepalive(struct iscsi_context *iscsi, int idle, int count, int interval)
@@ -620,27 +621,27 @@ int iscsi_set_tcp_keepalive(struct iscsi_context *iscsi, int idle, int count, in
 		iscsi_set_error(iscsi, "TCP: Failed to set socket option SO_KEEPALIVE. Error %s(%d)", strerror(errno), errno);
 		return -1;
 	}
-	DPRINTF(iscsi,3,"SO_KEEPALIVE set to %d",value);
+	ISCSI_LOG(iscsi, 3, "SO_KEEPALIVE set to %d",value);
 #ifdef TCP_KEEPCNT
 	if (set_tcp_sockopt(iscsi->fd, TCP_KEEPCNT, count) != 0) {
 		iscsi_set_error(iscsi, "TCP: Failed to set tcp keepalive count. Error %s(%d)", strerror(errno), errno);
 		return -1;
 	}
-	DPRINTF(iscsi,3,"TCP_KEEPCNT set to %d",count);
+	ISCSI_LOG(iscsi, 3, "TCP_KEEPCNT set to %d",count);
 #endif
 #ifdef TCP_KEEPINTVL
 	if (set_tcp_sockopt(iscsi->fd, TCP_KEEPINTVL, interval) != 0) {
 		iscsi_set_error(iscsi, "TCP: Failed to set tcp keepalive interval. Error %s(%d)", strerror(errno), errno);
 		return -1;
 	}
-	DPRINTF(iscsi,3,"TCP_KEEPINTVL set to %d",interval);
+	ISCSI_LOG(iscsi, 3, "TCP_KEEPINTVL set to %d",interval);
 #endif
 #ifdef TCP_KEEPIDLE
 	if (set_tcp_sockopt(iscsi->fd, TCP_KEEPIDLE, idle) != 0) {
 		iscsi_set_error(iscsi, "TCP: Failed to set tcp keepalive idle. Error %s(%d)", strerror(errno), errno);
 		return -1;
 	}
-	DPRINTF(iscsi,3,"TCP_KEEPIDLE set to %d",idle);
+	ISCSI_LOG(iscsi, 3, "TCP_KEEPIDLE set to %d",idle);
 #endif
 #endif
 

src/iscsi-inq.c

@@ -265,9 +265,10 @@ int main(int argc, const char *argv[])
 		exit(10);
 	}
 
-    if (debug > 0) {
+	if (debug > 0) {
-        iscsi_set_debug(iscsi, debug);
+		iscsi_set_log_level(iscsi, debug);
-    }
+		iscsi_set_log_fn(iscsi, iscsi_log_to_stderr);
+	}
 
 	if (url == NULL) {
 		fprintf(stderr, "You must specify the URL\n");

src/iscsi-ls.c

@@ -368,7 +368,8 @@ int main(int argc, const char *argv[])
 	}
 
 	if (debug > 0) {
-		iscsi_set_debug(iscsi, debug);
+		iscsi_set_log_level(iscsi, debug);
+		iscsi_set_log_fn(iscsi, iscsi_log_to_stderr);
 	}
 
 	iscsi_url = iscsi_parse_portal_url(iscsi, url);

src/iscsi-readcapacity16.c

@@ -108,7 +108,8 @@ int main(int argc, const char *argv[])
 	}
 
 	if (debug > 0) {
-		iscsi_set_debug(iscsi, debug);
+		iscsi_set_log_fn(iscsi, iscsi_log_to_stderr);
+		iscsi_set_log_level(iscsi, debug);
 	}
 
 	if (url == NULL) {