The /var/lib/nfs/rmtab file delineates fields in each of its lines
with a ":". The first field contains the IP address of a client, in
presentation format. IPv6 presentation format addresses contain
colons, which screws up the field delineation of rmtab.
Use a simple simple scheme to convert the colons in incoming client
names to some other character, and then convert them back when the
rmtab file is read.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
support/nfs/rmtab.c | 42 +++++++++++++++++++++++++++++++++++++++---
1 files changed, 39 insertions(+), 3 deletions(-)
diff --git a/support/nfs/rmtab.c b/support/nfs/rmtab.c
index a28abf3..ca789a3 100644
--- a/support/nfs/rmtab.c
+++ b/support/nfs/rmtab.c
@@ -19,6 +19,18 @@
#include <signal.h>
#include "nfslib.h"
+/*
+ * Colons in incoming IPv6 presentation addresses have to
+ * replaced with another character, since rmtab already
+ * uses colons to delineate fields.
+ *
+ * Use a printable character, but one that would never be
+ * found in a presentation address or domain name
+ */
+#define IPV6_COLON ';'
+
+#define LINELEN (2048)
+
static FILE *rmfp = NULL;
int
@@ -56,7 +68,8 @@ struct rmtabent *
fgetrmtabent(FILE *fp, int log, long *pos)
{
static struct rmtabent re;
- char buf[2048], *count, *host, *path;
+ char *count, *host, *path, *c;
+ static char buf[LINELEN];
errno = 0;
if (!fp)
@@ -84,10 +97,16 @@ fgetrmtabent(FILE *fp, int log, long *pos)
else
re.r_count = 1;
} while (0);
+
strncpy(re.r_client, host, sizeof (re.r_client) - 1);
re.r_client[sizeof (re.r_client) - 1] = '\0';
+ for (c = re.r_client; *c != '\0'; c++)
+ if (*c == IPV6_COLON)
+ *c = ':';
+
strncpy(re.r_path, path, sizeof (re.r_path) - 1);
re.r_path[sizeof (re.r_path) - 1] = '\0';
+
return &re;
}
@@ -100,10 +119,27 @@ putrmtabent(struct rmtabent *rep, long *pos)
void
fputrmtabent(FILE *fp, struct rmtabent *rep, long *pos)
{
+ static char buf[LINELEN];
+ char *c;
+
if (!fp || (pos && fseek (fp, *pos, SEEK_SET) != 0))
return;
- fprintf(fp, "%s:%s:0x%.8x\n", rep->r_client, rep->r_path,
- rep->r_count);
+
+ /*
+ * To avoid confusing the token parser in fgetrmtabent(),
+ * convert colons in incoming IPv6 presentation addresses
+ * to semicolons.
+ */
+ if (strlen(rep->r_client) > sizeof(buf)) {
+ xlog(L_ERROR, "client name too large");
+ return;
+ }
+ strncpy(buf, rep->r_client, sizeof(buf));
+ for (c = buf; *c != '\0'; c++)
+ if (*c == ':')
+ *c = IPV6_COLON;
+
+ (void)fprintf(fp, "%s:%s:0x%.8x\n", buf, rep->r_path, rep->r_count);
}
void
--
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