[ovs-dev] [PATCH v2] ofp-util: Fix parsing of parenthesized values within key-value pairs.
Ben Pfaff
blp at ovn.org
Mon Jun 13 21:54:59 UTC 2016
Reported-by: james hopper <jameshopper at email.com>
Reported-at: http://openvswitch.org/pipermail/discuss/2016-June/021662.html
Signed-off-by: Ben Pfaff <blp at ovn.org>
---
v1->v2: Fold in Andy Zhou's coding style suggestions.
AUTHORS | 1 +
lib/ofp-util.c | 111 ++++++++++++++++++++++++++++++--------------------
tests/ofp-util.at | 43 +++++++++++++++++++
tests/ofproto.at | 4 ++
utilities/ovs-ofctl.c | 21 ++++++++++
5 files changed, 136 insertions(+), 44 deletions(-)
diff --git a/AUTHORS b/AUTHORS
index 9fda4c1..e2ac267 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -452,6 +452,7 @@ Ziyou Wang ziyouw at vmware.com
Zoltán Balogh zoltan.balogh at ericsson.com
ankur dwivedi ankurengg2003 at gmail.com
chen zhang 3zhangchen9211 at gmail.com
+james hopper jameshopper at email.com
kk yap yapkke at stanford.edu
likunyun kunyunli at hotmail.com
meishengxin meishengxin at huawei.com
diff --git a/lib/ofp-util.c b/lib/ofp-util.c
index 21a2574..6519e62 100644
--- a/lib/ofp-util.c
+++ b/lib/ofp-util.c
@@ -7355,6 +7355,38 @@ ofputil_normalize_match_quiet(struct match *match)
ofputil_normalize_match__(match, false);
}
+static size_t
+parse_value(const char *s, const char *delimiters)
+{
+ size_t n = 0;
+
+ /* Iterate until we reach a delimiter.
+ *
+ * strchr(s, '\0') returns s+strlen(s), so this test handles the null
+ * terminator at the end of 's'. */
+ while (!strchr(delimiters, s[n])) {
+ if (s[n] == '(') {
+ int level = 0;
+ do {
+ switch (s[n]) {
+ case '\0':
+ return n;
+ case '(':
+ level++;
+ break;
+ case ')':
+ level--;
+ break;
+ }
+ n++;
+ } while (level > 0);
+ } else {
+ n++;
+ }
+ }
+ return n;
+}
+
/* Parses a key or a key-value pair from '*stringp'.
*
* On success: Stores the key into '*keyp'. Stores the value, if present, into
@@ -7368,58 +7400,49 @@ ofputil_normalize_match_quiet(struct match *match)
bool
ofputil_parse_key_value(char **stringp, char **keyp, char **valuep)
{
- char *pos, *key, *value;
- size_t key_len;
-
- pos = *stringp;
- pos += strspn(pos, ", \t\r\n");
- if (*pos == '\0') {
+ /* Skip white space and delimiters. If that brings us to the end of the
+ * input string, we are done and there are no more key-value pairs. */
+ *stringp += strspn(*stringp, ", \t\r\n");
+ if (**stringp == '\0') {
*keyp = *valuep = NULL;
return false;
}
- key = pos;
- key_len = strcspn(pos, ":=(, \t\r\n");
- if (key[key_len] == ':' || key[key_len] == '=') {
- /* The value can be separated by a colon. */
- size_t value_len;
-
- value = key + key_len + 1;
- value_len = strcspn(value, ", \t\r\n");
- pos = value + value_len + (value[value_len] != '\0');
- value[value_len] = '\0';
- } else if (key[key_len] == '(') {
- /* The value can be surrounded by balanced parentheses. The outermost
- * set of parentheses is removed. */
- int level = 1;
- size_t value_len;
-
- value = key + key_len + 1;
- for (value_len = 0; level > 0; value_len++) {
- switch (value[value_len]) {
- case '\0':
- level = 0;
- break;
-
- case '(':
- level++;
- break;
+ /* Extract the key and the delimiter that ends the key-value pair or begins
+ * the value. Advance the input position past the key and delimiter. */
+ char *key = *stringp;
+ size_t key_len = strcspn(key, ":=(, \t\r\n");
+ char key_delim = key[key_len];
+ key[key_len] = '\0';
+ *stringp += key_len + (key_delim != '\0');
- case ')':
- level--;
- break;
- }
- }
- value[value_len - 1] = '\0';
- pos = value + value_len;
+ /* Figure out what delimiter ends the value:
+ *
+ * - If key_delim is ":" or "=", the value extends until white space
+ * or a comma.
+ *
+ * - If key_delim is "(", the value extends until ")".
+ *
+ * If there is no value, we are done. */
+ const char *value_delims;
+ if (key_delim == ':' || key_delim == '=') {
+ value_delims = ", \t\r\n";
+ } else if (key_delim == '(') {
+ value_delims = ")";
} else {
- /* There might be no value at all. */
- value = key + key_len; /* Will become the empty string below. */
- pos = key + key_len + (key[key_len] != '\0');
+ *keyp = key;
+ *valuep = key + key_len; /* Empty string. */
+ return true;
}
- key[key_len] = '\0';
- *stringp = pos;
+ /* Extract the value. Advance the input position past the value and
+ * delimiter. */
+ char *value = *stringp;
+ size_t value_len = parse_value(value, value_delims);
+ char value_delim = value[value_len];
+ value[value_len] = '\0';
+ *stringp += value_len + (value_delim != '\0');
+
*keyp = key;
*valuep = value;
return true;
diff --git a/tests/ofp-util.at b/tests/ofp-util.at
index 248faf4..700173a 100644
--- a/tests/ofp-util.at
+++ b/tests/ofp-util.at
@@ -50,3 +50,46 @@ OFPT_HELLO (OF1.1) (xid=0x1):
version bitmap: 0x02
])
AT_CLEANUP
+
+AT_SETUP([parsing key-value pairs])
+dnl Key-only basics.
+AT_CHECK([ovs-ofctl parse-key-value a a,b 'a b' 'a b' 'a
+b'], 0, [a
+a, b
+a, b
+a, b
+a, b
+])
+
+dnl Key-value basics.
+AT_CHECK([ovs-ofctl parse-key-value a:b a=b a:b,c=d 'a=b c' 'a(b)' 'a(b),c(d)'], 0,
+[a=b
+a=b
+a=b, c=d
+a=b, c
+a=b
+a=b, c=d
+])
+
+dnl Values that contain nested delimiters.
+AT_CHECK([ovs-ofctl parse-key-value 'a:(b,c)' 'a:b(c,d)e' 'a(b,c(d,e),f)'], 0,
+[a=(b,c)
+a=b(c,d)e
+a=b,c(d,e),f
+])
+
+dnl Extraneous delimiters.
+AT_CHECK([ovs-ofctl parse-key-value a,,b ',a b' ' a b ,'], 0, [a, b
+a, b
+a, b
+])
+
+dnl Missing right parentheses.
+dnl
+dnl m4 can't handle unbalanced parentheses so we use @{:@, which
+dnl Autotest replaces by a left parenthesis.
+AT_CHECK([ovs-ofctl parse-key-value 'a@{:@b' 'a@{:@b(c)' 'a=b@{:@c'], 0, [a=b
+a=b(c)
+a=b@{:@c
+])
+AT_CLEANUP
diff --git a/tests/ofproto.at b/tests/ofproto.at
index 1ddee43..c89c641 100644
--- a/tests/ofproto.at
+++ b/tests/ofproto.at
@@ -783,6 +783,10 @@ OVS_VSWITCHD_START
AT_DATA([groups.txt], [dnl
group_id=1234,type=all,bucket=output:10
group_id=1235,type=all,bucket=output:10
+
+dnl This checks for regression against a parser bug such that
+dnl "actions=resbmit(,1)" etc. was rejected as a syntax error.
+group_id=2345,type=select,bucket=weight:10,actions=resubmit(,1),bucket=weight:10,actions=resubmit(,2),bucket=weight:1,actions=resubmit(,3)
])
AT_CHECK([ovs-ofctl -O OpenFlow13 -vwarn add-groups br0 groups.txt])
AT_CHECK([ovs-vsctl del-br br0])
diff --git a/utilities/ovs-ofctl.c b/utilities/ovs-ofctl.c
index 2ae0e81..5e42d1c 100644
--- a/utilities/ovs-ofctl.c
+++ b/utilities/ovs-ofctl.c
@@ -3969,6 +3969,26 @@ ofctl_encode_hello(struct ovs_cmdl_context *ctx)
ofpbuf_delete(hello);
}
+static void
+ofctl_parse_key_value(struct ovs_cmdl_context *ctx)
+{
+ for (size_t i = 1; i < ctx->argc; i++) {
+ char *s = ctx->argv[i];
+ char *key, *value;
+ int j = 0;
+ while (ofputil_parse_key_value(&s, &key, &value)) {
+ if (j++) {
+ fputs(", ", stdout);
+ }
+ fputs(key, stdout);
+ if (value[0]) {
+ printf("=%s", value);
+ }
+ }
+ putchar('\n');
+ }
+}
+
static const struct ovs_cmdl_command all_commands[] = {
{ "show", "switch",
1, 1, ofctl_show },
@@ -4094,6 +4114,7 @@ static const struct ovs_cmdl_command all_commands[] = {
{ "encode-error-reply", NULL, 2, 2, ofctl_encode_error_reply },
{ "ofp-print", NULL, 1, 2, ofctl_ofp_print },
{ "encode-hello", NULL, 1, 1, ofctl_encode_hello },
+ { "parse-key-value", NULL, 1, INT_MAX, ofctl_parse_key_value },
{ NULL, NULL, 0, 0, NULL },
};
--
2.1.3
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