Merge a prioritizer for IET scsi software target

Written by Olivier Lambert <lambert.olivier@gmail.com>

diff --git a/libmultipath/prioritizers/Makefile b/libmultipath/prioritizers/Makefile
index ece6347..6cfac88 100644 (file)
--- 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 (file)
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);
+}