onewire_parser: Add support for reading data from file system

[rrdd] / onewire_parser.c

diff --git a/onewire_parser.c b/onewire_parser.c
index 96bd5b2b0cfb8a873991f310f8ab6571683d2f55..f07f7d9d45e095943d2a65f39dce6da87ce62ec6 100644 (file)
--- a/onewire_parser.c
+++ b/onewire_parser.c
@@ -1,5 +1,9 @@
 #include <stdio.h>
 #include <ownetapi.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
 
 #include "parser.h"
 #include "debug.h"
@@ -73,30 +77,80 @@ static int make_uncached(char *path, size_t len)
        return 0;
 }
 
+static int owfs_read(const char *mount_point, const char *path, char **res)
+{
+       char result[64];
+       char file[2048];
+       int fd, ret;
+
+       snprintf(file, sizeof(file), "%s/%s", mount_point, path);
+
+       fd = open(file, O_RDONLY | O_CLOEXEC);
+       if (fd < 0) {
+               pr_err("Failed to open file %s: %m\n", file);
+               return -1;
+       }
+
+       ret = read(fd, result, sizeof(result));
+       if (ret < 0) {
+               pr_err("Failed to read from file %s: %m\n", file);
+               goto out_close;
+       }
+
+       *res = strndup(result, sizeof(result));
+
+out_close:
+       close(fd);
+
+       return ret;
+}
+
+static int is_mount_point(const char *str)
+{
+       /*
+        * Filesystem paths begin with a slash, everything else must
+        * be a network addresses
+        */
+       if (str[0] == '/')
+               return 1;
+
+       return 0;
+}
+
 static int onewire_parser(char *rrd_data, const char **parser_data)
 {
        OWNET_HANDLE h;
-       const char *server_addr;
+       const char *server_addr, *mount_point;
        char buf[24], *tmp;
        int i = 1, ret;
        int max_str = RRD_DATA_MAX_LEN;
+       int is_mountpoint = is_mount_point(parser_data[0]);
 
        if (!parser_data) {
                pr_err("No parser data available\n");
                return -1;
        }
 
-       server_addr = parser_data[0];
+       if (is_mountpoint) {
+               mount_point = parser_data[0];
 
-       if (!server_addr) {
-               pr_err("Server address not specified\n");
-               return -1;
-       }
+               if (!mount_point) {
+                       pr_err("Server address not specified\n");
+                       return -1;
+               }
+       } else {
+               server_addr = parser_data[0];
 
-       h = OWNET_init(server_addr);
-       if (h < 0) {
-               pr_err("Failed to connect to server %s\n", server_addr);
-               return -1;
+               if (!server_addr) {
+                       pr_err("Server address not specified\n");
+                       return -1;
+               }
+
+               h = OWNET_init(server_addr);
+               if (h < 0) {
+                       pr_err("Failed to connect to server %s\n", server_addr);
+                       return -1;
+               }
        }
 
        while (parser_data[i]) {
@@ -121,7 +175,11 @@ undefined:
 
                        pr_info("Reading data for entry %s with offset of %.2f\n",
                                ow_path, offset);
-                       ret = OWNET_read(h, ow_path, &tmp);
+
+                       if (is_mountpoint)
+                               ret = owfs_read(mount_point, ow_path, &tmp);
+                       else
+                               ret = OWNET_read(h, ow_path, &tmp);
 
                        /* Skip leading white space */
                        tmp2 = tmp;
@@ -180,7 +238,9 @@ next:
        }
        rrd_data = 0;
 
-       OWNET_finish();
+       if (!is_mountpoint)
+               OWNET_finish();
+
        return 0;
 }