diff options
Diffstat (limited to 'addons/ot/src/http.c')
-rw-r--r-- | addons/ot/src/http.c | 312 |
1 files changed, 312 insertions, 0 deletions
diff --git a/addons/ot/src/http.c b/addons/ot/src/http.c new file mode 100644 index 0000000..517bd0d --- /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 + */ |