Initial import from internal tree

jserv · jserv · commit a3a321fd42c9 · 2020-03-24T06:59:34.000Z
diff --git a/.clang-format b/.clang-format
@@ -0,0 +1,27 @@
+BasedOnStyle: Chromium
+Language: Cpp
+MaxEmptyLinesToKeep: 3
+IndentCaseLabels: false
+AllowShortIfStatementsOnASingleLine: false
+AllowShortCaseLabelsOnASingleLine: false
+AllowShortLoopsOnASingleLine: false
+DerivePointerAlignment: false
+PointerAlignment: Right
+SpaceAfterCStyleCast: true
+TabWidth: 4
+UseTab: Never
+IndentWidth: 4
+BreakBeforeBraces: Linux
+AccessModifierOffset: -4
+ForEachMacros:   
+  - foreach
+  - Q_FOREACH
+  - BOOST_FOREACH
+  - list_for_each
+  - list_for_each_safe
+  - list_for_each_entry
+  - list_for_each_entry_safe
+  - hlist_for_each_entry
+  - rb_list_foreach
+  - rb_list_foreach_safe
+  - vec_foreach
diff --git a/.gitignore b/.gitignore
@@ -0,0 +1,14 @@
+# kernel module compile output
+*.ko.cmd
+*.o.cmd
+.tmp_versions
+*.symvers
+*.mod.c
+*.mod.o
+*.order
+*.o
+*.ko
+
+# Other
+http_parser.c
+http_parser.h
diff --git a/LICENSE b/LICENSE
@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (C) 2020 National Cheng Kung University, Taiwan.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/Makefile b/Makefile
@@ -0,0 +1,24 @@
+CFILES = main.c http_server.c http_parser.c
+
+obj-m += khttpd.o
+khttpd-objs := $(CFILES:.c=.o)
+
+all: http_parser.c
+	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
+
+clean:
+	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean
+
+http_parser.c:
+	wget https://raw.githubusercontent.com/nodejs/http-parser/master/http_parser.c
+	sed -i 's/#include <assert.h>/#include "compat\/assert.h"/' $@
+	sed -i 's/#include <stddef.h>/#include "compat\/stddef.h"/' $@
+	sed -i 's/#include <ctype.h>/#include "compat\/ctype.h"/' $@
+	sed -i 's/#include <string.h>/#include "compat\/string.h"/' $@
+	sed -i 's/#include <limits.h>/#include "compat\/limits.h"/' $@
+	wget https://raw.githubusercontent.com/nodejs/http-parser/master/http_parser.h
+	sed -i 's/#include <stddef.h>/#include "compat\/stddef.h"/' http_parser.h
+	sed -i 's/#include <stdint.h>/#include "compat\/stdint.h"/' http_parser.h
+
+distclean: clean
+	$(RM) http_parser.c http_parser.h
diff --git a/README.md b/README.md
@@ -0,0 +1,17 @@
+# khttpd
+
+`khttpd` is an experimental HTTP server implemented as Linux kernel module.
+The server defaults to port 8081 but this can be easily configured using command line arguments to the LKM.
+
+## TODO
+* Request queue and/or cache
+* Slab cache
+* Kthread pool
+* Dynamic framework
+* Reverse proxy
+
+## License
+
+`khttpdc`is released under the MIT License. Use of this source code is governed by
+a MIT License that can be found in the LICENSE file. 
+
diff --git a/common.h b/common.h
@@ -0,0 +1,9 @@
+#ifndef KHTTPD_COMMON_H
+#define KHTTPD_COMMON_H
+
+#include "http_parser.h"
+#include "http_server.h"
+
+#define MODULE_NAME "khttpd"
+
+#endif
diff --git a/compat/assert.h b/compat/assert.h
@@ -0,0 +1,6 @@
+#ifndef COMPAT_ASSERT_H
+#define COMPAT_ASSERT_H
+
+static inline void assert(int x) {};
+
+#endif
diff --git a/compat/ctype.h b/compat/ctype.h
@@ -0,0 +1 @@
+/* Dummy */
diff --git a/compat/limits.h b/compat/limits.h
@@ -0,0 +1 @@
+/* Dummy */
diff --git a/compat/stddef.h b/compat/stddef.h
@@ -0,0 +1,2 @@
+#include <linux/types.h>
+#include <linux/kernel.h>
diff --git a/compat/stdint.h b/compat/stdint.h
@@ -0,0 +1 @@
+/* Dummy */
diff --git a/compat/string.h b/compat/string.h
@@ -0,0 +1,2 @@
+#include <linux/string.h>
+#include <linux/memory.h>
diff --git a/http_server.c b/http_server.c
@@ -0,0 +1,209 @@
+#include <linux/kthread.h>
+#include <linux/sched/signal.h>
+#include <linux/tcp.h>
+
+#include "common.h"
+
+#define CRLF "\r\n"
+
+#define HTTP_RESPONSE_200_DUMMY                              \
+    ""                                                       \
+    "HTTP/1.1 200 OK" CRLF "Server: " MODULE_NAME CRLF       \
+    "Content-Type: text/plain" CRLF "Content-Length: 8" CRLF \
+    "Connection: Close" CRLF CRLF "200 OK" CRLF
+#define HTTP_RESPONSE_200_KEEPALIVE_DUMMY                    \
+    ""                                                       \
+    "HTTP/1.1 200 OK" CRLF "Server: " MODULE_NAME CRLF       \
+    "Content-Type: text/plain" CRLF "Content-Length: 8" CRLF \
+    "Connection: Keep-Alive" CRLF CRLF "200 OK" CRLF
+#define HTTP_RESPONSE_501                                           \
+    ""                                                              \
+    "HTTP/1.1 501 Not Implemented" CRLF "Server: " MODULE_NAME CRLF \
+    "Content-Type: text/plain" CRLF "Content-Length: 21" CRLF       \
+    "Connection: Close" CRLF CRLF "501 Not Implemented" CRLF
+#define HTTP_RESPONSE_501_KEEPALIVE                                 \
+    ""                                                              \
+    "HTTP/1.1 501 Not Implemented" CRLF "Server: " MODULE_NAME CRLF \
+    "Content-Type: text/plain" CRLF "Content-Length: 21" CRLF       \
+    "Connection: KeepAlive" CRLF CRLF "501 Not Implemented" CRLF
+
+#define RECV_BUFFER_SIZE 4096
+
+struct http_request {
+    struct socket *socket;
+    enum http_method method;
+    char request_url[128];
+    int complete;
+};
+
+static int http_server_recv(struct socket *sock, char *buf, size_t size)
+{
+    struct kvec iov = {.iov_base = (void *) buf, .iov_len = size};
+    struct msghdr msg = {.msg_name = 0,
+                         .msg_namelen = 0,
+                         .msg_control = NULL,
+                         .msg_controllen = 0,
+                         .msg_flags = 0};
+    return kernel_recvmsg(sock, &msg, &iov, 1, size, msg.msg_flags);
+    ;
+}
+
+static int http_server_send(struct socket *sock, const char *buf, size_t size)
+{
+    struct msghdr msg = {.msg_name = NULL,
+                         .msg_namelen = 0,
+                         .msg_control = NULL,
+                         .msg_controllen = 0,
+                         .msg_flags = 0};
+    int done = 0;
+    while (done < size) {
+        struct kvec iov = {
+            .iov_base = (void *) ((char *) buf + done),
+            .iov_len = size - done,
+        };
+        int length = kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
+        if (length < 0) {
+            printk(KERN_ERR MODULE_NAME ": write error: %d\n", length);
+            break;
+        }
+        done += length;
+    }
+    return done;
+}
+
+static int http_server_response(struct http_request *request, int keep_alive)
+{
+    char *response;
+
+    printk(KERN_INFO MODULE_NAME ": requested_url = %s\n",
+           request->request_url);
+    if (request->method != HTTP_GET)
+        response = keep_alive ? HTTP_RESPONSE_501_KEEPALIVE : HTTP_RESPONSE_501;
+    else
+        response = keep_alive ? HTTP_RESPONSE_200_KEEPALIVE_DUMMY
+                              : HTTP_RESPONSE_200_DUMMY;
+    http_server_send(request->socket, response, strlen(response));
+    return 0;
+}
+
+static int http_parser_callback_message_begin(http_parser *parser)
+{
+    struct http_request *request = parser->data;
+    struct socket *socket = request->socket;
+    memset(request, 0x00, sizeof(struct http_request));
+    request->socket = socket;
+    return 0;
+}
+
+static int http_parser_callback_request_url(http_parser *parser,
+                                            const char *p,
+                                            size_t len)
+{
+    struct http_request *request = parser->data;
+    strncat(request->request_url, p, len);
+    return 0;
+}
+
+static int http_parser_callback_header_field(http_parser *parser,
+                                             const char *p,
+                                             size_t len)
+{
+    return 0;
+}
+
+static int http_parser_callback_header_value(http_parser *parser,
+                                             const char *p,
+                                             size_t len)
+{
+    return 0;
+}
+
+static int http_parser_callback_headers_complete(http_parser *parser)
+{
+    struct http_request *request = parser->data;
+    request->method = parser->method;
+    return 0;
+}
+
+static int http_parser_callback_body(http_parser *parser,
+                                     const char *p,
+                                     size_t len)
+{
+    return 0;
+}
+
+static int http_parser_callback_message_complete(http_parser *parser)
+{
+    struct http_request *request = parser->data;
+    http_server_response(request, http_should_keep_alive(parser));
+    request->complete = 1;
+    return 0;
+}
+
+static int http_server_worker(void *arg)
+{
+    char *buf;
+    struct http_parser parser;
+    struct http_parser_settings setting = {
+        .on_message_begin = http_parser_callback_message_begin,
+        .on_url = http_parser_callback_request_url,
+        .on_header_field = http_parser_callback_header_field,
+        .on_header_value = http_parser_callback_header_value,
+        .on_headers_complete = http_parser_callback_headers_complete,
+        .on_body = http_parser_callback_body,
+        .on_message_complete = http_parser_callback_message_complete};
+    struct http_request request;
+    struct socket *socket = (struct socket *) arg;
+
+    allow_signal(SIGKILL);
+    allow_signal(SIGTERM);
+    buf = kmalloc(RECV_BUFFER_SIZE, GFP_KERNEL);
+    if (!buf) {
+        printk(KERN_ERR MODULE_NAME ": can't allocate memory!\n");
+        return -1;
+    }
+    request.socket = socket;
+    http_parser_init(&parser, HTTP_REQUEST);
+    parser.data = &request;
+    while (!kthread_should_stop()) {
+        int ret = http_server_recv(socket, buf, RECV_BUFFER_SIZE - 1);
+        if (ret <= 0) {
+            if (ret)
+                printk(KERN_ERR MODULE_NAME ": recv error: %d\n", ret);
+            break;
+        }
+        http_parser_execute(&parser, &setting, buf, ret);
+        if (request.complete && !http_should_keep_alive(&parser))
+            break;
+    }
+    kernel_sock_shutdown(socket, SHUT_RDWR);
+    sock_release(socket);
+    kfree(buf);
+    return 0;
+}
+
+int http_server_daemon(void *arg)
+{
+    struct socket *socket;
+    struct task_struct *worker;
+    struct http_server_param *param = (struct http_server_param *) arg;
+
+    allow_signal(SIGKILL);
+    allow_signal(SIGTERM);
+
+    while (!kthread_should_stop()) {
+        int err = kernel_accept(param->listen_socket, &socket, 0);
+        if (err < 0) {
+            if (signal_pending(current))
+                break;
+            printk(KERN_ERR MODULE_NAME ": kernel_accept() error: %d\n", err);
+            continue;
+        }
+        worker = kthread_run(http_server_worker, socket, MODULE_NAME);
+        if (IS_ERR(worker)) {
+            printk(KERN_ERR MODULE_NAME ": can't create more worker process\n");
+            continue;
+        }
+    }
+    return 0;
+}
diff --git a/http_server.h b/http_server.h
@@ -0,0 +1,13 @@
+#ifndef KHTTPD_HTTP_SERVER_H
+#define KHTTPD_HTTP_SERVER_H
+
+#include <linux/types.h>
+#include <net/sock.h>
+
+struct http_server_param {
+    struct socket *listen_socket;
+};
+
+extern int http_server_daemon(void *arg);
+
+#endif
diff --git a/main.c b/main.c

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+#include <linux/types.h>`
	`2`	`+#include <linux/kernel.h>`