From 70a5e4b067f8df6aa989b7d8588fb71aeb253789 Mon Sep 17 00:00:00 2001
From: Christophe Varoqui <christophe.varoqui@opensvc.com>
Date: Wed, 9 Nov 2011 23:53:03 +0100
Subject: [PATCH] Merge a prioritizer for IET scsi software target

Written by Olivier Lambert <lambert.olivier@gmail.com>
---
 libmultipath/prioritizers/Makefile |   3 +-
 libmultipath/prioritizers/iet.c    | 123 +++++++++++++++++++++++++++++++++++++
 2 files changed, 125 insertions(+), 1 deletion(-)
 create mode 100644 libmultipath/prioritizers/iet.c

diff --git a/libmultipath/prioritizers/Makefile b/libmultipath/prioritizers/Makefile
index ece6347..6cfac88 100644
--- a/libmultipath/prioritizers/Makefile
+++ b/libmultipath/prioritizers/Makefile
@@ -14,7 +14,8 @@ LIBS = \
 	libprioontap.so \
 	libpriodatacore.so \
 	libpriohds.so \
-	libprioweightedpath.so
+	libprioweightedpath.so \
+	libprioiet.so
 
 CFLAGS += -I..
 
diff --git a/libmultipath/prioritizers/iet.c b/libmultipath/prioritizers/iet.c
new file mode 100644
index 0000000..1c7e196
--- /dev/null
+++ b/libmultipath/prioritizers/iet.c
@@ -0,0 +1,123 @@
+#include <dirent.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <stdio.h>
+#include <string.h>
+#include <regex.h>
+#include <prio.h>
+#include <debug.h>
+#include <unistd.h>
+
+#define dc_log(prio, msg) condlog(prio, "%s: iet prio: " msg, dev)
+// 
+// name: find_regex
+// @param string: string you want to search into
+// @param regex: the pattern used
+// @return result: string finded in string with regex, "none" if none
+char *find_regex (char * string, char * regex)
+{
+	int err;
+	regex_t preg;
+	err = regcomp (&preg, regex, REG_EXTENDED);
+	
+	if (err == 0) {
+			int match;
+			size_t nmatch = 0;
+			regmatch_t *pmatch = NULL;
+			nmatch = preg.re_nsub;
+			pmatch = malloc (sizeof (*pmatch) * nmatch);
+			
+			if (pmatch) {	
+				match = regexec (&preg, string, nmatch, pmatch, 0);
+				regfree (&preg);
+	
+				if (match == 0) {
+					char *result = NULL;
+					int start = pmatch[0].rm_so;
+					int end = pmatch[0].rm_eo;
+					size_t size = end - start;
+					result = malloc (sizeof (*result) * (size + 1));
+					
+					if (result) {
+						strncpy (result, &string[start], size);
+						result[size] = '\0';
+						return result;
+					}
+				}
+				else return "none";
+			}	
+		}
+		return "none";	
+}
+
+// 
+// name: inet_prio
+// @param
+// @return prio
+int iet_prio (const char *dev, char * args)
+{
+	char preferredip_buff[255] = "";
+	char * preferredip = &preferredip_buff[0];
+    // Phase 1 : checks. If anyone fails, return prio 0.
+    // check if args exists
+	if (!args) {
+		dc_log(0, "need prio_args with preferredip set");
+		return 0;
+    }
+    // check if args format is OK
+    if (sscanf(args, "preferredip=%s", preferredip) ==1) {}
+	else {
+		dc_log(0, "unexpected prio_args format");
+		return 0;
+	}
+	// check if ip is not too short
+	if (strlen(preferredip) <= 7) {
+		dc_log(0, "prio args: preferredip too short");
+		return 0;
+	}
+	// Phase 2 : find device in /dev/disk/by-path to match device/ip
+    DIR           *dir_p;
+    struct dirent *dir_entry_p;
+    enum { BUFFERSIZE = 1024 };
+    char buffer[BUFFERSIZE];
+    char fullpath[BUFFERSIZE] = "/dev/disk/by-path/";
+    dir_p = opendir(fullpath);
+	
+	// loop to find device in /dev/disk/by-path
+    while( NULL != (dir_entry_p = readdir(dir_p))) {
+		if (strncmp(dir_entry_p->d_name,".",1) != 0) {
+			char path[BUFFERSIZE] = "/dev/disk/by-path/";
+			strcat(path,dir_entry_p->d_name);
+	        ssize_t nchars = readlink(path, buffer, sizeof(buffer)-1);
+	        if (nchars != -1) {
+				buffer[nchars]='\0';
+				path[BUFFERSIZE]='\0';
+				char *device;
+				device = find_regex(buffer,"(sd[a-z]+)");
+				// if device parsed is the right one
+				if (strncmp(device,dev,strlen(device)) == 0) {
+					char *ip;
+					ip = find_regex(dir_entry_p->d_name,"([0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3})");
+					// if prefferedip and ip fetched matches
+					if (strncmp(ip,preferredip,strlen(ip)) == 0) {
+						// high prio
+						return 10;
+					}
+				}
+			}
+			else {
+				printf("error\n");
+				path[BUFFERSIZE]='\0';
+			}
+		}
+    }
+// nothing found, low prio 
+return 20;
+closedir(dir_p);
+}
+
+int getprio (struct path * pp, char * args)
+{
+        return iet_prio(pp->dev, args);
+}
-- 
2.7.4