MINOR: payload: add new sample fetch functions to process distcc protocol
When using haproxy in front of distccd, it's possible to provide significant
improvements by only connecting when the preprocessing is completed, and by
selecting different farms depending on the payload size. This patch provides
two new sample fetch functions :
distcc_param(<token>[,<occ>]) : integer
distcc_body(<token>[,<occ>]) : binary
diff --git a/src/payload.c b/src/payload.c
index b80a19c..492c72f 100644
--- a/src/payload.c
+++ b/src/payload.c
@@ -13,6 +13,7 @@
#include <stdlib.h>
#include <string.h>
+#include <common/net_helper.h>
#include <proto/acl.h>
#include <proto/arg.h>
#include <proto/channel.h>
@@ -909,6 +910,204 @@
return 1;
}
+/* extracts the parameter value of a distcc token */
+static int
+smp_fetch_distcc_param(const struct arg *arg_p, struct sample *smp, const char *kw, void *private)
+{
+ unsigned int match_tok = arg_p[0].data.sint;
+ unsigned int match_occ = arg_p[1].data.sint;
+ unsigned int token;
+ unsigned int param;
+ unsigned int body;
+ unsigned int ofs;
+ unsigned int occ;
+ struct channel *chn;
+ int i;
+
+ /* Format is (token[,occ]). occ starts at 1. */
+
+ if (!smp->strm)
+ return 0;
+
+ chn = ((smp->opt & SMP_OPT_DIR) == SMP_OPT_DIR_RES) ? &smp->strm->res : &smp->strm->req;
+
+ ofs = 0; occ = 0;
+ while (1) {
+ if (ofs + 12 > chn->buf->i) {
+ /* not there yet but could it at least fit ? */
+ if (!chn->buf->size)
+ goto too_short;
+
+ if (ofs + 12 <= channel_recv_limit(chn) + chn->buf->data - chn->buf->p)
+ goto too_short;
+
+ goto no_match;
+ }
+
+ token = read_n32(chn->buf->p + ofs);
+ ofs += 4;
+
+ for (i = param = 0; i < 8; i++) {
+ int c = hex2i(chn->buf->p[ofs + i]);
+
+ if (c < 0)
+ goto no_match;
+ param = (param << 4) + c;
+ }
+ ofs += 8;
+
+ /* these tokens don't have a body */
+ if (token != 0x41524743 /* ARGC */ && token != 0x44495354 /* DIST */ &&
+ token != 0x4E46494C /* NFIL */ && token != 0x53544154 /* STAT */ &&
+ token != 0x444F4E45 /* DONE */)
+ body = param;
+ else
+ body = 0;
+
+ if (token == match_tok) {
+ occ++;
+ if (!match_occ || match_occ == occ) {
+ /* found */
+ smp->data.type = SMP_T_SINT;
+ smp->data.u.sint = param;
+ smp->flags = SMP_F_VOLATILE | SMP_F_CONST;
+ return 1;
+ }
+ }
+ ofs += body;
+ }
+
+ too_short:
+ smp->flags = SMP_F_MAY_CHANGE | SMP_F_CONST;
+ return 0;
+ no_match:
+ /* will never match (end of buffer, or bad contents) */
+ smp->flags = 0;
+ return 0;
+
+}
+
+/* extracts the (possibly truncated) body of a distcc token */
+static int
+smp_fetch_distcc_body(const struct arg *arg_p, struct sample *smp, const char *kw, void *private)
+{
+ unsigned int match_tok = arg_p[0].data.sint;
+ unsigned int match_occ = arg_p[1].data.sint;
+ unsigned int token;
+ unsigned int param;
+ unsigned int ofs;
+ unsigned int occ;
+ unsigned int body;
+ struct channel *chn;
+ int i;
+
+ /* Format is (token[,occ]). occ starts at 1. */
+
+ if (!smp->strm)
+ return 0;
+
+ chn = ((smp->opt & SMP_OPT_DIR) == SMP_OPT_DIR_RES) ? &smp->strm->res : &smp->strm->req;
+
+ ofs = 0; occ = 0;
+ while (1) {
+ if (ofs + 12 > chn->buf->i) {
+ if (!chn->buf->size)
+ goto too_short;
+
+ if (ofs + 12 <= channel_recv_limit(chn) + chn->buf->data - chn->buf->p)
+ goto too_short;
+
+ goto no_match;
+ }
+
+ token = read_n32(chn->buf->p + ofs);
+ ofs += 4;
+
+ for (i = param = 0; i < 8; i++) {
+ int c = hex2i(chn->buf->p[ofs + i]);
+
+ if (c < 0)
+ goto no_match;
+ param = (param << 4) + c;
+ }
+ ofs += 8;
+
+ /* these tokens don't have a body */
+ if (token != 0x41524743 /* ARGC */ && token != 0x44495354 /* DIST */ &&
+ token != 0x4E46494C /* NFIL */ && token != 0x53544154 /* STAT */ &&
+ token != 0x444F4E45 /* DONE */)
+ body = param;
+ else
+ body = 0;
+
+ if (token == match_tok) {
+ occ++;
+ if (!match_occ || match_occ == occ) {
+ /* found */
+
+ smp->data.type = SMP_T_BIN;
+ smp->flags = SMP_F_VOLATILE | SMP_F_CONST;
+
+ if (ofs + body > chn->buf->p - chn->buf->data + chn->buf->i) {
+ /* incomplete body */
+
+ if (ofs + body > channel_recv_limit(chn) + chn->buf->data - chn->buf->p) {
+ /* truncate it to whatever will fit */
+ smp->flags |= SMP_F_MAY_CHANGE;
+ body = channel_recv_limit(chn) + chn->buf->data - chn->buf->p - ofs;
+ }
+ }
+
+ chunk_initlen(&smp->data.u.str, chn->buf->p + ofs, 0, body);
+ return 1;
+ }
+ }
+ ofs += body;
+ }
+
+ too_short:
+ smp->flags = SMP_F_MAY_CHANGE | SMP_F_CONST;
+ return 0;
+ no_match:
+ /* will never match (end of buffer, or bad contents) */
+ smp->flags = 0;
+ return 0;
+
+}
+
+/* This function is used to validate the arguments passed to a "distcc_param" or
+ * "distcc_body" sample fetch keyword. They take a mandatory token name of exactly
+ * 4 characters, followed by an optional occurrence number starting at 1. It is
+ * assumed that the types are already the correct ones. Returns 0 on error, non-
+ * zero if OK. If <err_msg> is not NULL, it will be filled with a pointer to an
+ * error message in case of error, that the caller is responsible for freeing.
+ * The initial location must either be freeable or NULL.
+ */
+int val_distcc(struct arg *arg, char **err_msg)
+{
+ unsigned int token;
+
+ if (arg[0].data.str.len != 4) {
+ memprintf(err_msg, "token name must be exactly 4 characters");
+ return 0;
+ }
+
+ /* convert the token name to an unsigned int (one byte per character,
+ * big endian format).
+ */
+ token = (arg[0].data.str.str[0] << 24) + (arg[0].data.str.str[1] << 16) +
+ (arg[0].data.str.str[2] << 8) + (arg[0].data.str.str[3] << 0);
+
+ arg[0].type = ARGT_SINT;
+ arg[0].data.sint = token;
+
+ if (arg[1].type != ARGT_SINT) {
+ arg[1].type = ARGT_SINT;
+ arg[1].data.sint = 0;
+ }
+ return 1;
+}
+
/************************************************************************/
/* All supported sample and ACL keywords must be declared here. */
/************************************************************************/
@@ -919,6 +1118,8 @@
* instance IPv4/IPv6 must be declared IPv4.
*/
static struct sample_fetch_kw_list smp_kws = {ILH, {
+ { "distcc_body", smp_fetch_distcc_body, ARG2(1,STR,SINT), val_distcc, SMP_T_BIN, SMP_USE_L6REQ|SMP_USE_L6RES },
+ { "distcc_param", smp_fetch_distcc_param, ARG2(1,STR,SINT), val_distcc, SMP_T_SINT, SMP_USE_L6REQ|SMP_USE_L6RES },
{ "payload", smp_fetch_payload, ARG2(2,SINT,SINT), NULL, SMP_T_BIN, SMP_USE_L6REQ|SMP_USE_L6RES },
{ "payload_lv", smp_fetch_payload_lv, ARG3(2,SINT,SINT,STR), val_payload_lv, SMP_T_BIN, SMP_USE_L6REQ|SMP_USE_L6RES },
{ "rdp_cookie", smp_fetch_rdp_cookie, ARG1(0,STR), NULL, SMP_T_STR, SMP_USE_L6REQ },