MINOR: sample: add param converter
Add a converter that extracts a parameter from string of delimited
key/value pairs.
Fixes: #1697
diff --git a/doc/configuration.txt b/doc/configuration.txt
index c45f0b4..0cc2bde 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -17702,6 +17702,32 @@
This prefix is followed by a name. The separator is a '.'. The name may only
contain characters 'a-z', 'A-Z', '0-9', '.' and '_'.
+param(<name>,[<delim>])
+ This extracts the first occurrence of the parameter <name> in the input string
+ where parameters are delimited by <delim>, which defaults to "&", and the name
+ and value of the parameter are separated by a "=". If there is no "=" and
+ value before the end of the parameter segment, it is treated as equivalent to
+ a value of an empty string.
+
+ This can be useful for extracting parameters from a query string, or possibly
+ a x-www-form-urlencoded body. In particular, `query,param(<name>)` can be used
+ as an alternative to `urlp(<name>)` which only uses "&" as a delimiter,
+ whereas "urlp" also uses "?" and ";".
+
+ Note that this converter doesn't do anything special with url encoded
+ characters. If you want to decode the value, you can use the url_dec converter
+ on the output. If the name of the parameter in the input might contain encoded
+ characters, you'll probably want do normalize the input before calling
+ "param". This can be done using "http-request normalize-uri", in particular
+ the percent-decode-unreserved and percent-to-uppercase options.
+
+ Example :
+ str(a=b&c=d&a=r),param(a) # b
+ str(a&b=c),param(a) # ""
+ str(a=&b&c=a),param(b) # ""
+ str(a=1;b=2;c=4),param(b,;) # 2
+ query,param(redirect_uri),urldec()
+
port_only
Converts a string which contains a Host header value into an integer by
returning its port.
diff --git a/reg-tests/converter/param.vtc b/reg-tests/converter/param.vtc
new file mode 100644
index 0000000..1633603
--- /dev/null
+++ b/reg-tests/converter/param.vtc
@@ -0,0 +1,80 @@
+varnishtest "param converter Test"
+
+feature ignore_unknown_macro
+
+server s1 {
+ rxreq
+ txresp -hdr "Connection: close"
+} -repeat 10 -start
+
+haproxy h1 -conf {
+ defaults
+ mode http
+ timeout connect "${HAPROXY_TEST_TIMEOUT-5s}"
+ timeout client "${HAPROXY_TEST_TIMEOUT-5s}"
+ timeout server "${HAPROXY_TEST_TIMEOUT-5s}"
+
+ frontend fe
+ bind "fd@${fe}"
+
+ ### requests
+ http-request set-var(txn.query) query
+ http-response set-header Found %[var(txn.query),param(test)] if { var(txn.query),param(test) -m found }
+
+ default_backend be
+
+ backend be
+ server s1 ${s1_addr}:${s1_port}
+} -start
+
+client c1 -connect ${h1_fe_sock} {
+ txreq -url "/foo/?test=1&b=4&d"
+ rxresp
+ expect resp.status == 200
+ expect resp.http.found == "1"
+
+ txreq -url "/?a=1&b=4&test=34"
+ rxresp
+ expect resp.status == 200
+ expect resp.http.found == "34"
+
+ txreq -url "/?test=bar"
+ rxresp
+ expect resp.status == 200
+ expect resp.http.found == "bar"
+
+ txreq -url "/?a=b&c=d"
+ rxresp
+ expect resp.status == 200
+ expect resp.http.found == "<undef>"
+
+ txreq -url "/?a=b&test=t&c=d"
+ rxresp
+ expect resp.status == 200
+ expect resp.http.found == "t"
+
+ txreq -url "/?a=b&test&c=d"
+ rxresp
+ expect resp.status == 200
+ expect resp.http.found == ""
+
+ txreq -url "/?test="
+ rxresp
+ expect resp.status == 200
+ expect resp.http.found == ""
+
+ txreq -url "/?a=b&test"
+ rxresp
+ expect resp.status == 200
+ expect resp.http.found == ""
+
+ txreq -url "/?testing=123"
+ rxresp
+ expect resp.status == 200
+ expect resp.http.found == "<undef>"
+
+ txreq -url "/?testing=123&test=4"
+ rxresp
+ expect resp.status == 200
+ expect resp.http.found == "4"
+} -run
diff --git a/src/sample.c b/src/sample.c
index 62a372b..7a612fc 100644
--- a/src/sample.c
+++ b/src/sample.c
@@ -2607,6 +2607,69 @@
return 1;
}
+static int sample_conv_param_check(struct arg *arg, struct sample_conv *conv,
+ const char *file, int line, char **err)
+{
+ if (arg[1].type == ARGT_STR && arg[1].data.str.data != 1) {
+ memprintf(err, "Delimiter must be exactly 1 character.");
+ return 0;
+ }
+
+ return 1;
+}
+
+static int sample_conv_param(const struct arg *arg_p, struct sample *smp, void *private)
+{
+ char *pos, *end, *pend, *equal;
+ char delim = '&';
+ const char *name = arg_p[0].data.str.area;
+ size_t name_l = arg_p[0].data.str.data;
+
+ if (arg_p[1].type == ARGT_STR)
+ delim = *arg_p[1].data.str.area;
+
+ pos = smp->data.u.str.area;
+ end = pos + smp->data.u.str.data;
+ while (pos < end) {
+ equal = pos + name_l;
+ /* Parameter not found */
+ if (equal > end)
+ break;
+
+ if (equal == end || *equal == delim) {
+ if (memcmp(pos, name, name_l) == 0) {
+ /* input contains parameter, but no value is supplied */
+ smp->data.u.str.data = 0;
+ return 1;
+ }
+ pos = equal + 1;
+ continue;
+ }
+
+ if (*equal == '=' && memcmp(pos, name, name_l) == 0) {
+ pos = equal + 1;
+ pend = memchr(pos, delim, end - pos);
+ if (pend == NULL)
+ pend = end;
+
+ if (smp->data.u.str.size)
+ smp->data.u.str.size -= pos - smp->data.u.str.area;
+ smp->data.u.str.area = pos;
+ smp->data.u.str.data = pend - pos;
+ return 1;
+ }
+ /* find the next delimiter and set position to character after that */
+ pos = memchr(pos, delim, end - pos);
+ if (pos == NULL)
+ pos = end;
+ else
+ pos++;
+ }
+ /* Parameter not found */
+ smp->data.u.str.data = 0;
+ return 0;
+}
+
static int sample_conv_regsub_check(struct arg *args, struct sample_conv *conv,
const char *file, int line, char **err)
{
@@ -4399,6 +4462,7 @@
{ "bytes", sample_conv_bytes, ARG2(1,SINT,SINT), NULL, SMP_T_BIN, SMP_T_BIN },
{ "field", sample_conv_field, ARG3(2,SINT,STR,SINT), sample_conv_field_check, SMP_T_STR, SMP_T_STR },
{ "word", sample_conv_word, ARG3(2,SINT,STR,SINT), sample_conv_field_check, SMP_T_STR, SMP_T_STR },
+ { "param", sample_conv_param, ARG2(1,STR,STR), sample_conv_param_check, SMP_T_STR, SMP_T_STR },
{ "regsub", sample_conv_regsub, ARG3(2,REG,STR,STR), sample_conv_regsub_check, SMP_T_STR, SMP_T_STR },
{ "sha1", sample_conv_sha1, 0, NULL, SMP_T_BIN, SMP_T_BIN },
{ "strcmp", sample_conv_strcmp, ARG1(1,STR), smp_check_strcmp, SMP_T_STR, SMP_T_SINT },