user/httpd

2 files changed, 89 insertions, 3 deletions

diff --git a/src/user/app/httpd/httpd.c b/src/user/app/httpd/httpd.c
new file mode 100644
index 0000000..1aaebc5
--- /dev/null
+++ b/src/user/app/httpd/httpd.c
@@ -0,0 +1,80 @@
+/* garbage httpd, just to see if it works
+ * easily DoSable (like the rest of the network stack), vulnerable to path traversal, etc */
+#include <camellia/flags.h>
+#include <camellia/syscalls.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#define eprintf(fmt, ...) fprintf(stderr, "httpd: "fmt"\n" __VA_OPT__(,) __VA_ARGS__)
+
+static void handle(FILE *c) {
+	char buf[2048];
+	fgets(buf, sizeof buf, c);
+	printf("%s", buf);
+
+	if (memcmp(buf, "GET /", 5) != 0) {
+		fprintf(c, "HTTP/1.1 400 Bad Request\r\n\r\n");
+		return;
+	}
+	char *path = buf + 4;
+	char *end = strchr(path, ' ');
+	if (end) *end = '\0';
+
+	handle_t h = _syscall_open(path, strlen(path), OPEN_RO);
+	if (h < 0) {
+		fprintf(c, "HTTP/1.1 404 Not Found\r\n\r\n");
+		return;
+	}
+	FILE *f = fdopen(h, "r");
+	if (!f) {
+		fprintf(c, "HTTP/1.1 500 Internal Server Error\r\n\r\n");
+		return;
+	}
+
+	if (path[strlen(path) - 1] != '/') {
+		/* regular file */
+		fprintf(c, "HTTP/1.1 200 OK\r\n");
+		fprintf(c, "\r\n");
+		for (;;) {
+			int len = fread(buf, 1, sizeof buf, f);
+			if (len <= 0) break;
+			fwrite(buf, 1, len, c);
+		}
+	} else {
+		/* directory listing */
+		fprintf(c, "HTTP/1.1 200 OK\r\n");
+		fprintf(c, "Content-Type: text/html; charset=UTF-8\r\n");
+		fprintf(c, "\r\n");
+		fprintf(c, "<h1>directory listing for %s</h1><hr><ul><li><a href=..>..</a></li>", path);
+		for (;;) {
+			int len = fread(buf, 1, sizeof buf, f);
+			if (len <= 0) break;
+			// TODO directory library
+			// based on find.c
+			for (int pos = 0; pos < len; ) {
+				if (buf[pos] == '\0') break;
+				const char *end = memchr(buf + pos, 0, len - pos);
+				if (!end) break;
+				fprintf(c, "<li><a href=\"%s\">%s</a></li>", buf + pos, buf + pos);
+				pos += end - (buf + pos) + 1;
+			}
+		}
+	}
+	fclose(f);
+}
+
+int main(int argc, char **argv) {
+	const char *path = (argc > 1) ? argv[1] : "/net/0.0.0.0/listen/tcp/80";
+	handle_t conn;
+	for (;;) {
+		conn = _syscall_open(path, strlen(path), 0);
+		if (conn < 0) {
+			eprintf("open('%s') failed, %d", path, conn);
+			return 1;
+		}
+		FILE *f = fdopen(conn, "a+");
+		handle(f);
+		fclose(f);
+	}
+}
diff --git a/src/user/app/netstack/fs.c b/src/user/app/netstack/fs.c
index f4d9625..9f40ef8 100644
--- a/src/user/app/netstack/fs.c
+++ b/src/user/app/netstack/fs.c
@@ -12,6 +12,7 @@
  */
 #include "proto.h"
 #include "util.h"
+#include <camellia/flags.h>
 #include <camellia/syscalls.h>
 #include <errno.h>
 #include <stdio.h>
@@ -58,7 +59,9 @@ static void tcp_recv_callback(void *arg) {
 	struct handle *h = arg;
 	char buf[1024];
 	if (h->reqh >= 0) {
-		size_t len = tcpc_tryread(h->tcp.c, buf, sizeof buf);
+		if (h->tcp.readcap > sizeof buf)
+			h->tcp.readcap = sizeof buf;
+		size_t len = tcpc_tryread(h->tcp.c, buf, h->tcp.readcap);
 		if (len > 0) {
 			_syscall_fs_respond(h->reqh, buf, len, 0);
 			h->reqh = -1;
@@ -122,7 +125,7 @@ static void recv_enqueue(struct handle *h, handle_t reqh, size_t readcap) {
 	}
 }
 
-static void fs_open(handle_t reqh, char *path) {
+static void fs_open(handle_t reqh, char *path, int flags) {
 #define respond(buf, val) do{ _syscall_fs_respond(reqh, buf, val, 0); return; }while(0)
 	struct handle *h;
 	if (*path != '/') respond(NULL, -1);
@@ -140,6 +143,9 @@ static void fs_open(handle_t reqh, char *path) {
 		respond(h, 0);
 	}
 
+	/* everything below ends up sending packets */
+	if (flags & OPEN_RO) respond(NULL, -EACCES);
+
 	char *save;
 	const char *verb, *proto, *port_s;
 
@@ -241,7 +247,7 @@ void fs_thread(void *arg) { (void)arg;
 			case VFSOP_OPEN:
 				if (res.len < buflen) {
 					buf[res.len] = '\0';
-					fs_open(reqh, buf);
+					fs_open(reqh, buf, res.flags);
 				} else {
 					_syscall_fs_respond(reqh, NULL, -1, 0);
 				}