Initial commitv0.1.0

libunit-wasm and example C and Rust WebAssembly modules for NGINX Unit.

Co-developed-by: Timo Stark <t.stark@nginx.com>
Co-developed-by: Liam Crilly <liam@nginx.com>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>

1 files changed, 381 insertions, 0 deletions

diff --git a/src/c/libunit-wasm.c b/src/c/libunit-wasm.c
new file mode 100644
index 0000000..1860fe3
--- /dev/null
+++ b/src/c/libunit-wasm.c
@@ -0,0 +1,381 @@
+/* SPDX-License-Identifier: Apache-2.0 */
+
+/*
+ * Copyright (C) Andrew Clayton
+ * Copyright (C) F5, Inc.
+ */
+
+#define _GNU_SOURCE
+
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <stdarg.h>
+#include <string.h>
+#include <errno.h>
+
+#include "unit/unit-wasm.h"
+
+/*
+ * Some handlers are required some are optional.
+ *
+ * They are defined as _weak_ symbols so they can be overridden
+ * in the module.
+ */
+
+/* Optional Handlers */
+__attribute__((export_name("luw_module_init_handler"), __weak__))
+void luw_module_init_handler(void)
+{
+}
+
+__attribute__((export_name("luw_module_end_handler"), __weak__))
+void luw_module_end_handler(void)
+{
+}
+
+__attribute__((export_name("luw_request_init_handler"), __weak__))
+void luw_request_init_handler(void)
+{
+}
+
+__attribute__((export_name("luw_request_end_handler"), __weak__))
+void luw_request_end_handler(void)
+{
+}
+
+__attribute__((export_name("luw_response_end_handler"), __weak__))
+void luw_response_end_handler(void)
+{
+}
+
+/* Required Handlers */
+__attribute__((export_name("luw_request_handler"), __weak__))
+int luw_request_handler(u8 *addr)
+{
+	(void)addr;
+
+	return 0;
+}
+
+__attribute__((export_name("luw_free_handler"), __weak__))
+void luw_free_handler(u32 addr)
+{
+        free((void *)addr);
+}
+
+__attribute__((export_name("luw_malloc_handler"), __weak__))
+u32 luw_malloc_handler(size_t size)
+{
+        return (u32)malloc(size);
+}
+
+void luw_init_ctx(luw_ctx_t *ctx, u8 *addr, size_t offset)
+{
+	*ctx = (luw_ctx_t){ };
+
+	ctx->addr = addr;
+	ctx->req = (struct luw_req *)addr;
+	ctx->resp = (struct luw_resp *)(addr + offset);
+	ctx->mem = ctx->resp->data;
+	ctx->resp_offset = offset;
+	ctx->resp->size = 0;
+	ctx->resp_hdr->nr_fields = 0;
+}
+
+/*
+ * Allows to set an external buffer to be used as a copy for
+ * the request.
+ *
+ * The flags dictate a few behaviours
+ *
+ * LUW_SRB_NONE		- No specific action to be performed. It will
+ *			  simply copy the request data into the specified
+ *			  buffer.
+ *
+ * LUW_SRB_APPEND	- Sets up append mode whereby multiple successive
+ *			  requests will be appended to the specified buffer.
+ *
+ *			  The first request will have all its metadata
+ *			  copied. Subsequent requests will _only_ have the
+ *			  actual body data appended.
+ *
+ * LUW_SRB_ALLOC	- Allocate memory for the specified buffer.
+ *
+ * LUW_SRB_FULL_SIZE	- Used in conjunction with LUW_SRB_ALLOC. By
+ *			  default only ctx->req->request_size is
+ *			  allocated. If this flag is present it says to
+ *			  allocate memory for the _entire_ request that
+ *			  will eventually be sent.
+ */
+int luw_set_req_buf(luw_ctx_t *ctx, u8 **buf, unsigned long flags)
+{
+	size_t alloc_size;
+	size_t copy_bytes;
+
+	/* Check for unknown flags */
+	if (flags & ~LUW_SRB_FLAGS_ALL) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	/* Check for invalid combinations of flags */
+	if (flags & LUW_SRB_FULL_SIZE && !(flags & LUW_SRB_ALLOC)) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	alloc_size = copy_bytes = ctx->req->request_size;
+
+	if (flags & LUW_SRB_FULL_SIZE)
+		alloc_size = ctx->req->content_off + ctx->req->content_len;
+
+	if (flags & LUW_SRB_ALLOC) {
+		*buf = malloc(alloc_size);
+		if (!*buf)
+			return -1;
+	}
+
+	memcpy(*buf, ctx->addr, copy_bytes);
+	ctx->req_buf = *buf;
+	ctx->req = (struct luw_req *)ctx->req_buf;
+	ctx->reqp = ctx->req_buf;
+
+	if (flags & LUW_SRB_APPEND)
+		ctx->reqp = ctx->req_buf + copy_bytes;
+
+	return 0;
+}
+
+const char *luw_get_http_path(const luw_ctx_t *ctx)
+{
+	return (const char *)ctx->req + ctx->req->path_off;
+}
+
+const char *luw_get_http_method(const luw_ctx_t *ctx)
+{
+	return (const char *)ctx->req + ctx->req->method_off;
+}
+
+const char *luw_get_http_version(const luw_ctx_t *ctx)
+{
+	return (const char *)ctx->req + ctx->req->version_off;
+}
+
+const char *luw_get_http_query(const luw_ctx_t *ctx)
+{
+	return (const char *)ctx->req + ctx->req->query_off;
+}
+
+const char *luw_get_http_remote(const luw_ctx_t *ctx)
+{
+	return (const char *)ctx->req + ctx->req->remote_off;
+}
+
+const char *luw_get_http_local_addr(const luw_ctx_t *ctx)
+{
+	return (const char *)ctx->req + ctx->req->local_addr_off;
+}
+
+const char *luw_get_http_local_port(const luw_ctx_t *ctx)
+{
+	return (const char *)ctx->req + ctx->req->local_port_off;
+}
+
+const char *luw_get_http_server_name(const luw_ctx_t *ctx)
+{
+	return (const char *)ctx->req + ctx->req->server_name_off;
+}
+
+const u8 *luw_get_http_content(const luw_ctx_t *ctx)
+{
+	return (u8 *)ctx->req + ctx->req->content_off;
+}
+
+/* Returns the size of the overall content length */
+size_t luw_get_http_content_len(const luw_ctx_t *ctx)
+{
+	return ctx->req->content_len;
+}
+
+/* Returns the size of the content sent in _this_ request */
+size_t luw_get_http_content_sent(const luw_ctx_t *ctx)
+{
+	return ctx->req->content_sent;
+}
+
+bool luw_http_is_tls(const luw_ctx_t *ctx)
+{
+	return ctx->req->tls;
+}
+
+void luw_http_hdr_iter(luw_ctx_t *ctx,
+		       bool (*luw_http_hdr_iter_func)(luw_ctx_t *ctx,
+						      const char *name,
+						      const char *value,
+						      void *data),
+		       void *user_data)
+{
+	struct luw_hdr_field *hf;
+	struct luw_hdr_field *hf_end;
+
+	hf_end = ctx->req->fields + ctx->req->nr_fields;
+	for (hf = ctx->req->fields; hf < hf_end; hf++) {
+		const char *name = (const char *)ctx->req + hf->name_off;
+		const char *value = (const char *)ctx->req + hf->value_off;
+		bool again;
+
+		again = luw_http_hdr_iter_func(ctx, name, value, user_data);
+		if (!again)
+			break;
+	}
+}
+
+const char *luw_http_hdr_get_value(luw_ctx_t *ctx, const char *hdr)
+{
+	luw_http_hdr_iter_t *iter;
+	const char *name;
+	const char *value;
+
+	luw_foreach_http_hdr((*ctx), iter, name, value) {
+		if (strcasecmp(name, hdr) == 0)
+			return value;
+	}
+
+	return NULL;
+}
+
+/* Returns the size of ctx->resp->data[] */
+size_t luw_get_response_data_size(const luw_ctx_t *ctx)
+{
+	return ctx->mem - ctx->resp->data;
+}
+
+/* Appends (non-nul terminmates) formatted data to the response buffer */
+__attribute__((__format__(printf, 2, 3)))
+int luw_mem_writep(luw_ctx_t *ctx, const char *fmt, ...)
+{
+	int len;
+	char *logbuf;
+	va_list ap;
+
+	va_start(ap, fmt);
+	len = vasprintf(&logbuf, fmt, ap);
+	if (len == -1) {
+		va_end(ap);
+		return -1;
+	}
+	va_end(ap);
+
+	ctx->mem = mempcpy(ctx->mem, logbuf, len);
+	ctx->resp->size += len;
+
+	free(logbuf);
+
+	return len;
+}
+
+/* Appends data of length size to the response buffer */
+size_t luw_mem_writep_data(luw_ctx_t *ctx, const u8 *src, size_t size)
+{
+	ctx->mem = mempcpy(ctx->mem, src, size);
+	ctx->resp->size += size;
+
+	return ctx->resp->size;
+}
+
+/* Append data from the request to the previously setup request_buffer. */
+void luw_req_buf_append(luw_ctx_t *ctx, const u8 *src)
+{
+	struct luw_req *req = (struct luw_req *)src;
+
+	ctx->reqp = mempcpy(ctx->reqp, src + req->content_off,
+			    req->request_size);
+	ctx->req->content_sent = req->content_sent;
+	ctx->req->total_content_sent = req->total_content_sent;
+}
+
+/*
+ * Convenience function to fill the response buffer with data from
+ * the request buffer.
+ *
+ * The runtime allocates NXT_WASM_MEM_SIZE + NXT_WASM_PAGE_SIZE
+ * bytes so we don't need to worry about the size of the actual
+ * response structures.
+ */
+size_t luw_mem_fill_buf_from_req(luw_ctx_t *ctx, size_t from)
+{
+	size_t write_bytes;
+	size_t mem_size = nxt_wasm_get_init_mem_size();
+
+	write_bytes = ctx->req->content_sent;
+	if (write_bytes > mem_size)
+		write_bytes = mem_size;
+
+	memcpy(ctx->resp->data, ctx->req_buf + ctx->req->content_off + from,
+	       write_bytes);
+	ctx->resp->size = write_bytes;
+
+	return write_bytes;
+}
+
+void luw_mem_reset(luw_ctx_t *ctx)
+{
+	ctx->mem = ctx->resp->data;
+	ctx->resp->size = 0;
+	ctx->resp_hdr->nr_fields = 0;
+}
+
+void luw_http_send_response(const luw_ctx_t *ctx)
+{
+	nxt_wasm_send_response(ctx->resp_offset);
+}
+
+void luw_http_init_headers(luw_ctx_t *ctx, size_t nr, size_t offset)
+{
+	ctx->resp_hdr = (struct luw_resp_hdr *)(ctx->addr + offset);
+	ctx->hdrp = (u8 *)ctx->resp_hdr + sizeof(struct luw_resp_hdr) +
+		(nr * sizeof(struct luw_hdr_field));
+
+	ctx->resp_hdr->nr_fields = nr;
+}
+
+void luw_http_add_header(luw_ctx_t *ctx, u16 idx, const char *name,
+			 const char *value)
+{
+	ctx->resp_hdr->fields[idx].name_off = ctx->hdrp - ctx->addr;
+	ctx->resp_hdr->fields[idx].name_len = strlen(name);
+	ctx->hdrp = mempcpy(ctx->hdrp, name, strlen(name));
+
+	ctx->resp_hdr->fields[idx].value_off = ctx->hdrp - ctx->addr;
+	ctx->resp_hdr->fields[idx].value_len = strlen(value);
+	ctx->hdrp = mempcpy(ctx->hdrp, value, strlen(value));
+}
+
+void luw_http_send_headers(const luw_ctx_t *ctx)
+{
+	nxt_wasm_send_headers((u8 *)ctx->resp_hdr - ctx->addr);
+}
+
+void luw_http_response_end(void)
+{
+	nxt_wasm_response_end();
+}
+
+u32 luw_mem_get_init_size(void)
+{
+	return nxt_wasm_get_init_mem_size();
+}
+
+/* These are really just convenience wrappers for the rust bindings... */
+
+void *luw_malloc(size_t size)
+{
+	return malloc(size);
+}
+
+void luw_free(void *ptr)
+{
+	free(ptr);
+}