mpage · December 7, 2011 21:45 · Dec 7, 2011
diff --git a/this could conceivably replace repquota b/this could conceivably replace repquota
@@ -0,0 +1,177 @@
+#include <assert.h>
+#include <errno.h>
+#include <fstab.h>
+#include <inttypes.h>
+#include <malloc.h>
+#include <mntent.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/quota.h>
+
+#define dqblk_print_field(dqblk, field) printf("%llu ", (dqblk).(field))
+
+/**
+ * Attempts to look up the device name associated with supplied mount point.
+ *
+ * @param dir      Mount point to look up
+ * @param dev_name Where to place the device name. Caller must free.
+ *
+ * @return         0 on success
+ *                -1 mount point not found
+ */
+static int lookup_device(const char* dir, char** dev_name) {
+  FILE* mtab = NULL;
+  struct mntent* mtab_entry = NULL;
+  size_t fsname_len = 0;
+  int retval = -1;
+
+  /* Using /etc/mtab here is supposedly a no-no, but the macro we're supposed
+   * to use (_PATH_MNTTAB) resolves to "/etc/fstab" (at least on my Ubuntu system).
+   */
+  mtab = setmntent("/etc/mtab", "r");
+  if (NULL == mtab) {
+    return -2;
+  }
+
+  /* Could move into conditional, but prefer this stylistically */
+  mtab_entry = getmntent(mtab);
+  while (NULL != mtab_entry) {
+    if (!strcmp(mtab_entry->mnt_dir, dir)) {
+      fsname_len = strlen(mtab_entry->mnt_fsname) + 1;
+
+      *dev_name = malloc(fsname_len);
+      assert(NULL != *dev_name);
+
+      strncpy(*dev_name, mtab_entry->mnt_fsname, fsname_len);
+      retval = 0;
+      break;
+    }
+
+    mtab_entry = getmntent(mtab);
+  }
+
+  endmntent(mtab);
+
+  return retval;
+}
+
+/**
+ * Attempts to print a helpful error message to stderr.
+ *
+ * @param msg Error message to prepend.
+ */
+static void print_quotactl_error(const char* msg) {
+  assert(NULL != msg);
+
+  switch (errno) {
+    case EFAULT:
+      fprintf(stderr, "%s: Block device invalid.\n", msg);
+      break;
+
+    case ENOENT:
+      fprintf(stderr, "%s: Block device doesn't exist.\n", msg);
+      break;
+
+    case ENOSYS:
+      fprintf(stderr, "%s: Kernel doesn't haven quota support.\n", msg);
+      break;
+
+    case ENOTBLK:
+      fprintf(stderr, "%s: Not a block device.\n", msg);
+      break;
+
+    case EPERM:
+      fprintf(stderr, "%s: Insufficient privilege.\n", msg);
+      break;
+
+    case ESRCH:
+      fprintf(stderr, "%s: No quota for supplied user.\n", msg);
+      break;
+
+    default:
+      perror(msg);
+      break;
+  }
+}
+
+/**
+ * Prints relevant quota information to stdout for the supplied uid.
+ * On failure, will attempt to print a helpful error messge to stderr.
+ *
+ * @param filesystem  Filesystem to report quota information for
+ * @param uid         Uid to report quota information for
+ *
+ * @return            -1 on error, 0 otherwise
+ */
+static int print_quota_usage(const char* filesystem, int uid) {
+  assert(NULL != filesystem);
+
+  char emsg[1024];
+  struct dqblk quota_info;
+
+  memset(&quota_info, 0, sizeof(struct dqblk));
+
+  if (quotactl(QCMD(Q_GETQUOTA, USRQUOTA), filesystem, uid, (caddr_t) &quota_info) < 0) {
+    sprintf(emsg, "Failed retrieving quota for uid=%d", uid);
+    print_quotactl_error(emsg);
+    return -1;
+  }
+
+  printf("%d ", uid);
+
+  /* Block info */
+  printf("%llu %llu %llu %llu ",
+         (long long unsigned int) quota_info.dqb_curspace,
+         (long long unsigned int) quota_info.dqb_bsoftlimit,
+         (long long unsigned int) quota_info.dqb_bhardlimit,
+         (long long unsigned int) quota_info.dqb_btime);
+
+  /* Inode info */
+  printf("%llu %llu %llu %llu\n",
+         (long long unsigned int) quota_info.dqb_curinodes,
+         (long long unsigned int) quota_info.dqb_isoftlimit,
+         (long long unsigned int) quota_info.dqb_ihardlimit,
+         (long long unsigned int) quota_info.dqb_itime);
+
+  return 0;
+}
+
+int
+main(int argc, char* argv[]) {
+  char* device_name = NULL;
+  int* uids = NULL;
+  int ii = 0, num_uids = 0;
+
+  if (argc < 3) {
+    printf("Usage: report_quota [filesystem] [uid]+\n");
+    printf("Reports quota information for the supplied uids on the given filesystem\n");
+    printf("Format is: <uid> <blocks used> <soft> <hard> <grace> <inodes used> <soft> <hard> <grace>\n");
+    exit(1);
+  }
+
+  if (lookup_device(argv[1], &device_name) < 0) {
+    printf("Couldn't find device for %s", argv[1]);
+    exit(1);
+  }
+
+  num_uids = argc - 2;
+  uids = malloc(sizeof(int) * num_uids);
+  if (NULL == uids) {
+    perror("malloc()");
+    free(device_name);
+    exit(1);
+  }
+  memset(uids, 0, sizeof(int) * num_uids);
+  for (ii = 0; ii < num_uids; ii++) {
+    uids[ii] = atoi(argv[ii + 2]);
+  }
+
+  for (ii = 0; ii < num_uids; ii++) {
+    print_quota_usage(device_name, uids[ii]);
+  }
+
+  free(device_name);
+
+  return 0;
+}