fabrics: Read system UUID from DMI and merge hostnqn generation functions

Ported from nvme-cli.

Signed-off-by: Hannes Reinecke <hare@suse.de>

diff --git a/src/nvme/fabrics.c b/src/nvme/fabrics.c
index 4c5970449789e27808b595d6ffe9e40d3159a798..ad2fe7b994e2e441ba734130949bb3f5d050a95d 100644 (file)
--- a/src/nvme/fabrics.c
+++ b/src/nvme/fabrics.c
@@ -17,6 +17,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
+#include <dirent.h>
 
 #include <sys/stat.h>
 #include <sys/types.h>
@@ -568,30 +569,110 @@ out_free_log:
        return ret;
 }
 
-#ifdef CONFIG_SYSTEMD
-char *nvmf_hostnqn_generate()
+#define PATH_DMI_ENTRIES       "/sys/firmware/dmi/entries"
+
+int uuid_from_dmi(char *system_uuid)
 {
-       char *ret = NULL;
-       sd_id128_t id;
+       int f;
+       DIR *d;
+       struct dirent *de;
+       char buf[512];
+
+       system_uuid[0] = '\0';
+       d = opendir(PATH_DMI_ENTRIES);
+       if (!d)
+               return -ENXIO;
+       while ((de = readdir(d))) {
+               char filename[PATH_MAX];
+               int len, type;
+
+               if (de->d_name[0] == '.')
+                       continue;
+               sprintf(filename, "%s/%s/type", PATH_DMI_ENTRIES, de->d_name);
+               f = open(filename, O_RDONLY);
+               if (f < 0)
+                       continue;
+               len = read(f, buf, 512);
+               len = read(f, buf, 512);
+               close(f);
+               if (len < 0)
+                       continue;
+               if (sscanf(buf, "%d", &type) != 1)
+                       continue;
+               if (type != 1)
+                       continue;
+               sprintf(filename, "%s/%s/raw", PATH_DMI_ENTRIES, de->d_name);
+               f = open(filename, O_RDONLY);
+               if (f < 0)
+                       continue;
+               len = read(f, buf, 512);
+               close(f);
+               if (len < 0)
+                       continue;
+               /* Sigh. https://en.wikipedia.org/wiki/Overengineering */
+               /* DMTF SMBIOS 3.0 Section 7.2.1 System UUID */
+               sprintf(system_uuid,
+                       "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-"
+                       "%02x%02x%02x%02x%02x%02x",
+                       (uint8_t)buf[8 + 3], (uint8_t)buf[8 + 2],
+                       (uint8_t)buf[8 + 1], (uint8_t)buf[8 + 0],
+                       (uint8_t)buf[8 + 5], (uint8_t)buf[8 + 4],
+                       (uint8_t)buf[8 + 7], (uint8_t)buf[8 + 6],
+                       (uint8_t)buf[8 + 8], (uint8_t)buf[8 + 9],
+                       (uint8_t)buf[8 + 10], (uint8_t)buf[8 + 11],
+                       (uint8_t)buf[8 + 12], (uint8_t)buf[8 + 13],
+                       (uint8_t)buf[8 + 14], (uint8_t)buf[8 + 15]);
+               break;
+       }
+       closedir(d);
+       return strlen(system_uuid) ? 0 : -ENXIO;
+}
 
-       if (sd_id128_get_machine_app_specific(NVME_HOSTNQN_ID, &id) < 0)
-               return NULL;
+#ifdef CONFIG_SYSTEMD
+#include <systemd/sd-id128.h>
+#define NVME_HOSTNQN_ID SD_ID128_MAKE(c7,f4,61,81,12,be,49,32,8c,83,10,6f,9d,dd,d8,6b)
+#endif
 
-       if (asprintf(&ret,
-                    "nqn.2014-08.org.nvmexpress:uuid:" SD_ID128_FORMAT_STR "\n",
-                    SD_ID128_FORMAT_VAL(id)) < 0)
-               ret = NULL;
+static int uuid_from_systemd(char *system_uuid)
+{
+       int ret = -ENOTSUP;
+#ifdef CONFIG_SYSTEMD
+       sd_id128_t id;
 
+       ret = sd_id128_get_machine_app_specific(NVME_HOSTNQN_ID, &id);
+       if (!ret)
+               asprintf(systemd_uuid, SD_ID128_FORMAT_STR,
+                        SD_ID128_FORMAT_VAL(id));
+#endif
        return ret;
 }
-#else
+
 char *nvmf_hostnqn_generate()
 {
-       errno = ENOTSUP;
-       return NULL;
-}
+       char *hostnqn;
+       int ret;
+       char uuid_str[37]; /* e.g. 1b4e28ba-2fa1-11d2-883f-0016d3cca427 + \0 */
+#ifdef CONFIG_LIBUUID
+       uuid_t uuid;
 #endif
 
+       ret = uuid_from_dmi(uuid_str);
+       if (ret < 0)
+               ret = uuid_from_systemd(uuid_str);
+#ifdef CONFIG_LIBUUID
+       if (ret < 0) {
+               uuid_generate_random(uuid);
+               uuid_unparse_lower(uuid, uuid_str);
+               ret = 0;
+       }
+#endif
+       if (ret < 0)
+               return NULL;
+
+       asprintf(&hostnqn, "nqn.2014-08.org.nvmexpress:uuid:%s\n", uuid_str);
+       return hostnqn;
+}
+
 static char *nvmf_read_file(const char *f, int len)
 {
        char buf[len];