[bug 3757] final cleanup

bk: 62401e9e8aU7rMtkqdy3Y8hZ-k-WzQ

diff --git a/ntpd/ntp_ppsdev.c b/ntpd/ntp_ppsdev.c
index 8d29b65fd0005aafbad3d76d3376fb46157d139a..cb2c887653369dc57d632de9a9196af3b6b1604b 100644 (file)
--- a/ntpd/ntp_ppsdev.c
+++ b/ntpd/ntp_ppsdev.c
@@ -100,8 +100,13 @@ xdirOpenAt(
 }
 
 /* --------------------------------------------------------------------
- * read content of a file (with a size limit) into  piece of allocated
+ * read content of a file (with a size limit) into a piece of allocated
  * memory and trim any trailing whitespace.
+ *
+ * The issue here is that several files in the 'sysfs' tree claim a size
+ * of 4096 bytes when you 'stat' them -- but reading gives EOF after a
+ * few chars.  (I *can* understand why the kernel takes this shortcut.
+ * it's just a bit unwieldy...)
  */
 static char*
 readFileAt(
@@ -109,24 +114,28 @@ readFileAt(
        const char *path)
 {
        struct stat sb;
-       char *ret = NULL, *tmp;
+       char *ret = NULL;
        ssize_t rdlen;
        int dfd;
        
        if (-1 == (dfd = openat(rfd, path, OModeF)) || -1 == fstat(dfd, &sb))
                goto fail;
-       if ((sb.st_size > 0x2000) || (NULL == (tmp = malloc(sb.st_size + 1))))
+       if ((sb.st_size > 0x2000) || (NULL == (ret = malloc(sb.st_size + 1))))
                goto fail;
-       if (1 > (rdlen = read(dfd, tmp, sb.st_size)))
+       if (1 > (rdlen = read(dfd, ret, sb.st_size)))
                goto fail;
-       while (rdlen > 0 && tmp[rdlen - 1] <= ' ')
+       close(dfd);
+
+       while (rdlen > 0 && ret[rdlen - 1] <= ' ')
                --rdlen;
-       tmp[rdlen] = '\0';
-       ret = tmp;
+       ret[rdlen] = '\0';
+       return ret;
+
   fail:
+       free(ret);
        if (-1 != dfd)
                close(dfd);
-       return ret;    
+       return NULL;    
 }
 
 /* --------------------------------------------------------------------
@@ -142,20 +151,23 @@ findDevByDevId(
        XDIR           xdir;
        char          *name = NULL;
        
-       if (xdirOpenAt(&xdir, AT_FDCWD, "/dev")) {
-               while (!name && (dent = readdir(xdir.dir))) {
-                       if (-1 == fstatat(xdir.dfd, dent->d_name,
-                                         &sb, AT_SYMLINK_NOFOLLOW))
-                               continue;
-                       if (!S_ISCHR(sb.st_mode))
-                               continue;
-                       if (sb.st_rdev == rdev) {
-                               if (-1 == asprintf(&name, "/dev/%s", dent->d_name))
-                                       name = NULL;
-                       }
+       if (!xdirOpenAt(&xdir, AT_FDCWD, "/dev"))
+               goto done;
+       
+       while (!name && (dent = readdir(xdir.dir))) {
+               if (-1 == fstatat(xdir.dfd, dent->d_name,
+                                 &sb, AT_SYMLINK_NOFOLLOW))
+                       continue;
+               if (!S_ISCHR(sb.st_mode))
+                       continue;
+               if (sb.st_rdev == rdev) {
+                       if (-1 == asprintf(&name, "/dev/%s", dent->d_name))
+                               name = NULL;
                }
-               xdirClose(&xdir);
        }
+       xdirClose(&xdir);
+
+  done:
        return name;
 }
 
@@ -197,26 +209,33 @@ getPpsTuple(
        unsigned long dmaj, dmin;
        struct stat   sb;
        char         *bufp, *endp, *scan;
-       
+
+       /* 'path' contains the primary path to the associated TTY:
+        * we 'stat()' for the device id in 'st_rdev'.
+        */
        if (NULL == (bufp = readFileAt(fdDir, "path")))
-               goto fail;
+               goto done;
        if ((-1 == stat(bufp, &sb)) || !S_ISCHR(sb.st_mode))
-               goto fail;
+               goto done;
        *pTty = sb.st_rdev;
        free(bufp);
-       
+
+       /* 'dev' holds the device ID of the PPS device as 'major:minor'
+        * in text format.   *sigh* couldn't that simply be the name of
+        * the PPS device itself, as in 'path' above??? But nooooo....
+        */
        if (NULL == (bufp = readFileAt(fdDir, "dev")))
-               goto fail;
+               goto done;
        dmaj = strtoul((scan = bufp), &endp, 10);
        if ((endp == scan) || (*endp != ':') || (dmaj >= 256))
-               goto fail;
+               goto done;
        dmin = strtoul((scan = endp + 1), &endp, 10);
        if ((endp == scan) || (*endp >= ' ') || (dmin >= 256))
-               goto fail;
+               goto done;
        *pPps = makedev((unsigned int)dmaj, (unsigned int)dmin);
        rc = TRUE;
        
-  fail:
+  done:
        free(bufp);
        return rc;      
 }
@@ -232,28 +251,39 @@ findPpsDevId(
        dev_t  ttyId ,
        dev_t *pPpsId)
 {
-       BOOL found = FALSE;
-       XDIR ClsDir;
+       BOOL           found = FALSE;
+       XDIR           ClassDir;
+       struct dirent *dent;
+       dev_t          othId, ppsId;
+       int            fdDevDir;
        
-       if (xdirOpenAt(&ClsDir, AT_FDCWD, "/sys/class/pps")) {
-               struct dirent *dent;
-               dev_t          othId, ppsId;
+       if (!xdirOpenAt(&ClassDir, AT_FDCWD, "/sys/class/pps"))
+               goto done;
                
-               while (!found && (dent = readdir(ClsDir.dir))) {
-                       int   fdDevDir;
-                       if (strncmp("pps", dent->d_name, 3))
-                               continue;
-                       if (-1 == (fdDevDir = openat(
-                                          ClsDir.dfd, dent->d_name, OModeD)))
-                               continue;
-                       found = getPpsTuple(fdDevDir, &othId, &ppsId)
-                            && (ttyId == othId);
-                       close(fdDevDir);
-               }
-               if (found)
-                       *pPpsId = ppsId;
-               xdirClose(&ClsDir);
+       while (!found && (dent = readdir(ClassDir.dir))) {
+
+               /* If the entry is not a referring to a PPS device or
+                * if we can't open the directory for reading, skipt it:
+                */
+               if (strncmp("pps", dent->d_name, 3))
+                       continue;
+               fdDevDir = openat(ClassDir.dfd, dent->d_name, OModeD);
+               if (-1 == fdDevDir)
+                       continue;
+
+               /* get the data and check if device ID for the TTY
+                * is what we're looking for:
+                */
+               found = getPpsTuple(fdDevDir, &othId, &ppsId)
+                   && (ttyId == othId);
+               close(fdDevDir);
        }
+       
+       xdirClose(&ClassDir);
+       
+       if (found)
+               *pPpsId = ppsId;
+  done:
        return found;
 }
 
@@ -308,8 +338,8 @@ findMatchingPpsDev(
        if (!dpath)
                goto done;
 
-       /* And since ince we're 'root', we might as well try to clone
-        * the ownership and access rights from the original TTY to the
+       /* And since we're 'root', we might as well try to clone the
+        * ownership and access rights from the original TTY to the
         * PPS device.  If that does not work, we just have to live with
         * what we've got so far...
         */