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-rw-r--r--addons/ot/src/http.c312
1 files changed, 312 insertions, 0 deletions
diff --git a/addons/ot/src/http.c b/addons/ot/src/http.c
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--- /dev/null
+++ b/addons/ot/src/http.c
@@ -0,0 +1,312 @@
+/***
+ * Copyright 2020 HAProxy Technologies
+ *
+ * This file is part of the HAProxy OpenTracing filter.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+#include "include.h"
+
+
+#ifdef DEBUG_OT
+
+/***
+ * NAME
+ * flt_ot_http_headers_dump -
+ *
+ * ARGUMENTS
+ * chn -
+ *
+ * DESCRIPTION
+ * -
+ *
+ * RETURN VALUE
+ * This function does not return a value.
+ */
+void flt_ot_http_headers_dump(const struct channel *chn)
+{
+ const struct htx *htx;
+ int32_t pos;
+
+ FLT_OT_FUNC("%p", chn);
+
+ if (chn == NULL)
+ FLT_OT_RETURN();
+
+ htx = htxbuf(&(chn->buf));
+
+ if (htx_is_empty(htx))
+ FLT_OT_RETURN();
+
+ for (pos = htx_get_first(htx); pos != -1; pos = htx_get_next(htx, pos)) {
+ struct htx_blk *blk = htx_get_blk(htx, pos);
+ enum htx_blk_type type = htx_get_blk_type(blk);
+
+ if (type == HTX_BLK_HDR) {
+ struct ist n = htx_get_blk_name(htx, blk);
+ struct ist v = htx_get_blk_value(htx, blk);
+
+ FLT_OT_DBG(2, "'%.*s: %.*s'", (int)n.len, n.ptr, (int)v.len, v.ptr);
+ }
+ else if (type == HTX_BLK_EOH)
+ break;
+ }
+
+ FLT_OT_RETURN();
+}
+
+#endif /* DEBUG_OT */
+
+
+/***
+ * NAME
+ * flt_ot_http_headers_get -
+ *
+ * ARGUMENTS
+ * chn -
+ * prefix -
+ * len -
+ * err -
+ *
+ * DESCRIPTION
+ * This function is very similar to function http_action_set_header(), from
+ * the HAProxy source.
+ *
+ * RETURN VALUE
+ * -
+ */
+struct otc_text_map *flt_ot_http_headers_get(struct channel *chn, const char *prefix, size_t len, char **err)
+{
+ const struct htx *htx;
+ size_t prefix_len = (!FLT_OT_STR_ISVALID(prefix) || (len == 0)) ? 0 : (len + 1);
+ int32_t pos;
+ struct otc_text_map *retptr = NULL;
+
+ FLT_OT_FUNC("%p, \"%s\", %zu, %p:%p", chn, prefix, len, FLT_OT_DPTR_ARGS(err));
+
+ if (chn == NULL)
+ FLT_OT_RETURN_PTR(retptr);
+
+ /*
+ * The keyword 'inject' allows you to define the name of the OpenTracing
+ * context without using a prefix. In that case all HTTP headers are
+ * transferred because it is not possible to separate them from the
+ * OpenTracing context (this separation is usually done via a prefix).
+ *
+ * When using the 'extract' keyword, the context name must be specified.
+ * To allow all HTTP headers to be extracted, the first character of
+ * that name must be set to FLT_OT_PARSE_CTX_IGNORE_NAME.
+ */
+ if (FLT_OT_STR_ISVALID(prefix) && (*prefix == FLT_OT_PARSE_CTX_IGNORE_NAME))
+ prefix_len = 0;
+
+ htx = htxbuf(&(chn->buf));
+
+ for (pos = htx_get_first(htx); pos != -1; pos = htx_get_next(htx, pos)) {
+ struct htx_blk *blk = htx_get_blk(htx, pos);
+ enum htx_blk_type type = htx_get_blk_type(blk);
+
+ if (type == HTX_BLK_HDR) {
+ struct ist v, n = htx_get_blk_name(htx, blk);
+
+ if ((prefix_len == 0) || ((n.len >= prefix_len) && (strncasecmp(n.ptr, prefix, len) == 0))) {
+ if (retptr == NULL) {
+ retptr = otc_text_map_new(NULL, 8);
+ if (retptr == NULL) {
+ FLT_OT_ERR("failed to create HTTP header data");
+
+ break;
+ }
+ }
+
+ v = htx_get_blk_value(htx, blk);
+
+ /*
+ * In case the data of the HTTP header is not
+ * specified, v.ptr will have some non-null
+ * value and v.len will be equal to 0. The
+ * otc_text_map_add() function will not
+ * interpret this well. In this case v.ptr
+ * is set to an empty string.
+ */
+ if (v.len == 0)
+ v = ist("");
+
+ /*
+ * Here, an HTTP header (which is actually part
+ * of the span context is added to the text_map.
+ *
+ * Before adding, the prefix is removed from the
+ * HTTP header name.
+ */
+ if (otc_text_map_add(retptr, n.ptr + prefix_len, n.len - prefix_len, v.ptr, v.len, OTC_TEXT_MAP_DUP_KEY | OTC_TEXT_MAP_DUP_VALUE) == -1) {
+ FLT_OT_ERR("failed to add HTTP header data");
+
+ otc_text_map_destroy(&retptr, OTC_TEXT_MAP_FREE_KEY | OTC_TEXT_MAP_FREE_VALUE);
+
+ break;
+ }
+ }
+ }
+ else if (type == HTX_BLK_EOH)
+ break;
+ }
+
+ ot_text_map_show(retptr);
+
+ if ((retptr != NULL) && (retptr->count == 0)) {
+ FLT_OT_DBG(2, "WARNING: no HTTP headers found");
+
+ otc_text_map_destroy(&retptr, OTC_TEXT_MAP_FREE_KEY | OTC_TEXT_MAP_FREE_VALUE);
+ }
+
+ FLT_OT_RETURN_PTR(retptr);
+}
+
+
+/***
+ * NAME
+ * flt_ot_http_header_set -
+ *
+ * ARGUMENTS
+ * chn -
+ * prefix -
+ * name -
+ * value -
+ * err -
+ *
+ * DESCRIPTION
+ * This function is very similar to function http_action_set_header(), from
+ * the HAProxy source.
+ *
+ * RETURN VALUE
+ * -
+ */
+int flt_ot_http_header_set(struct channel *chn, const char *prefix, const char *name, const char *value, char **err)
+{
+ struct http_hdr_ctx ctx = { .blk = NULL };
+ struct ist ist_name;
+ struct buffer *buffer = NULL;
+ struct htx *htx;
+ int retval = -1;
+
+ FLT_OT_FUNC("%p, \"%s\", \"%s\", \"%s\", %p:%p", chn, prefix, name, value, FLT_OT_DPTR_ARGS(err));
+
+ if ((chn == NULL) || (!FLT_OT_STR_ISVALID(prefix) && !FLT_OT_STR_ISVALID(name)))
+ FLT_OT_RETURN_INT(retval);
+
+ htx = htxbuf(&(chn->buf));
+
+ /*
+ * Very rare (about 1% of cases), htx is empty.
+ * In order to avoid segmentation fault, we exit this function.
+ */
+ if (htx_is_empty(htx)) {
+ FLT_OT_ERR("HTX is empty");
+
+ FLT_OT_RETURN_INT(retval);
+ }
+
+ if (!FLT_OT_STR_ISVALID(prefix)) {
+ ist_name = ist2((char *)name, strlen(name));
+ }
+ else if (!FLT_OT_STR_ISVALID(name)) {
+ ist_name = ist2((char *)prefix, strlen(prefix));
+ }
+ else {
+ buffer = flt_ot_trash_alloc(0, err);
+ if (buffer == NULL)
+ FLT_OT_RETURN_INT(retval);
+
+ (void)chunk_printf(buffer, "%s-%s", prefix, name);
+
+ ist_name = ist2(buffer->area, buffer->data);
+ }
+
+ /* Remove all occurrences of the header. */
+ while (http_find_header(htx, ist(""), &ctx, 1) == 1) {
+ struct ist n = htx_get_blk_name(htx, ctx.blk);
+#ifdef DEBUG_OT
+ struct ist v = htx_get_blk_value(htx, ctx.blk);
+#endif
+
+ /*
+ * If the <name> parameter is not set, then remove all headers
+ * that start with the contents of the <prefix> parameter.
+ */
+ if (!FLT_OT_STR_ISVALID(name))
+ n.len = ist_name.len;
+
+ if (isteqi(n, ist_name))
+ if (http_remove_header(htx, &ctx) == 1)
+ FLT_OT_DBG(3, "HTTP header '%.*s: %.*s' removed", (int)n.len, n.ptr, (int)v.len, v.ptr);
+ }
+
+ /*
+ * If the value pointer has a value of NULL, the HTTP header is not set
+ * after deletion.
+ */
+ if (value == NULL) {
+ /* Do nothing. */
+ }
+ else if (http_add_header(htx, ist_name, ist(value)) == 1) {
+ retval = 0;
+
+ FLT_OT_DBG(3, "HTTP header '%s: %s' added", ist_name.ptr, value);
+ }
+ else {
+ FLT_OT_ERR("failed to set HTTP header '%s: %s'", ist_name.ptr, value);
+ }
+
+ flt_ot_trash_free(&buffer);
+
+ FLT_OT_RETURN_INT(retval);
+}
+
+
+/***
+ * NAME
+ * flt_ot_http_headers_remove -
+ *
+ * ARGUMENTS
+ * chn -
+ * prefix -
+ * err -
+ *
+ * DESCRIPTION
+ * -
+ *
+ * RETURN VALUE
+ * -
+ */
+int flt_ot_http_headers_remove(struct channel *chn, const char *prefix, char **err)
+{
+ int retval;
+
+ FLT_OT_FUNC("%p, \"%s\", %p:%p", chn, prefix, FLT_OT_DPTR_ARGS(err));
+
+ retval = flt_ot_http_header_set(chn, prefix, NULL, NULL, err);
+
+ FLT_OT_RETURN_INT(retval);
+}
+
+/*
+ * Local variables:
+ * c-indent-level: 8
+ * c-basic-offset: 8
+ * End:
+ *
+ * vi: noexpandtab shiftwidth=8 tabstop=8
+ */