Add the foundation of the "VEXT" mechanism

bin/varnishd/Makefile.am

@@ -57,6 +57,7 @@ varnishd_SOURCES = \
 	cache/cache_ws_common.c \
 	common/common_vsc.c \
 	common/common_vsmw.c \
+	common/common_vext.c \
 	hash/hash_classic.c \
 	hash/hash_critbit.c \
 	hash/hash_simple_list.c \

bin/varnishd/common/common_vext.c

+/*-
+ * Copyright (c) 2022 Varnish Software AS
+ * All rights reserved.
+ *
+ * Author: Poul-Henning Kamp <phk@phk.freebsd.dk>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * Loadable extensions
+ */
+
+#include "config.h"
+
+#include <dlfcn.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "vdef.h"
+#include "vas.h"
+#include "miniobj.h"
+#include "vav.h"
+#include "vqueue.h"
+#include "vrnd.h"
+#include "vsb.h"
+
+#include "heritage.h"
+
+struct vext {
+	unsigned		magic;
+#define VEXT_MAGIC		0xd5063ef6
+	VTAILQ_ENTRY(vext)	list;
+
+	char			**argv;
+	int			fd;
+	struct vsb		*vsb;
+	void			*dlptr;
+};
+
+static VTAILQ_HEAD(,vext) vext_list =
+    VTAILQ_HEAD_INITIALIZER(vext_list);
+
+void
+vext_argument(const char *arg)
+{
+	struct vext *vp;
+
+	fprintf(stderr, "EEE <%s>\n", arg);
+	ALLOC_OBJ(vp, VEXT_MAGIC);
+	AN(vp);
+	vp->argv = VAV_Parse(arg, NULL, ARGV_COMMA);
+	AN(vp->argv);
+	if (vp->argv[0] != NULL)
+		ARGV_ERR("\tParse failure in argument: %s\n\t%s\n",
+		    arg, vp->argv[0]);
+	VTAILQ_INSERT_TAIL(&vext_list, vp, list);
+	fprintf(stderr, "eee <%s>\n", vp->argv[1]);
+	vp->fd = open(vp->argv[1], O_RDONLY);
+	if (vp->fd < 0)
+		ARGV_ERR("\tCannot open %s\n\t%s\n",
+		    vp->argv[1], strerror(errno));
+}
+
+void
+vext_copyin(struct vsb *vident)
+{
+	struct vext *vp;
+	const char *p;
+	int i, fdo;
+	unsigned u;
+	char buf[BUFSIZ];
+	ssize_t sz, szw;
+
+	VTAILQ_FOREACH(vp, &vext_list, list) {
+		if (vp->vsb == NULL) {
+			vp->vsb = VSB_new_auto();
+			AN(vp->vsb);
+		}
+		VSB_clear(vp->vsb);
+		p = strrchr(vp->argv[1], '/');
+		if (p != NULL)
+			p++;
+		else
+			p = vp->argv[0];
+		VSB_printf(vident, ",-E%s", p);
+		VSB_printf(vp->vsb, "vext_cache/%s,", p);
+		for (i = 0; i < 8; i++) {
+			AZ(VRND_RandomCrypto(&u, sizeof u));
+			u %= 26;
+			VSB_printf(vp->vsb, "%c", 'a' + (char)u);
+		}
+		VSB_printf(vp->vsb, ".so");
+		AZ(VSB_finish(vp->vsb));
+		fprintf(stderr, "ee2 %s\n", VSB_data(vp->vsb));
+		fdo = open(VSB_data(vp->vsb), O_WRONLY|O_CREAT|O_EXCL, 0700);
+		xxxassert(fdo >= 0);
+		AZ(lseek(vp->fd, 0, SEEK_SET));
+		do {
+			sz = read(vp->fd, buf, sizeof buf);
+			if (sz > 0) {
+				szw = write(fdo, buf, sz);
+				xxxassert(szw == sz);
+			}
+		} while (sz > 0);
+		closefd(&fdo);
+		closefd(&vp->fd);
+	}
+}
+
+void
+vext_load(void)
+{
+	struct vext *vp;
+
+	VTAILQ_FOREACH(vp, &vext_list, list) {
+		vp->dlptr = dlopen(
+		    VSB_data(vp->vsb),
+		    RTLD_NOW | RTLD_GLOBAL
+		);
+		if (vp->dlptr == NULL) {
+			XXXAN(vp->dlptr);
+		}
+		fprintf(stderr, "Loaded -E %s\n", VSB_data(vp->vsb));
+	}
+}
+
+void
+vext_cleanup(void)
+{
+	struct vext *vp;
+
+	VTAILQ_FOREACH(vp, &vext_list, list) {
+		fprintf(stderr, "ee3 %s\n", VSB_data(vp->vsb));
+		if (vp->vsb != NULL && VSB_len(vp->vsb) > 0) {
+			XXXAZ(unlink(VSB_data(vp->vsb)));
+			VSB_clear(vp->vsb);
+		}
+	}
+}

bin/varnishd/common/heritage.h

@@ -129,3 +129,9 @@ extern vsm_lock_f *vsc_unlock;
 extern vsm_lock_f *vsmw_lock;
 extern vsm_lock_f *vsmw_unlock;
 
+/* common/common_vext.c */
+
+void vext_argument(const char *);
+void vext_copyin(struct vsb *);
+void vext_load(void);
+void vext_cleanup(void);

bin/varnishd/mgt/mgt_child.c

@@ -378,6 +378,8 @@ mgt_launch_child(struct cli *cli)
 		heritage.cls = mgt_cls;
 		heritage.ident = VSB_data(vident) + 1;
 
+		vext_load();
+
 		VJ_subproc(JAIL_SUBPROC_WORKER);
 
 		heritage.proc_vsmw = VSMW_New(heritage.vsm_fd, 0640, "_.index");
@@ -385,7 +387,7 @@ mgt_launch_child(struct cli *cli)
 
 		/*
 		 * We pass these two params because child_main needs them
-		 * Well before it has found its own param struct.
+		 * well before it has found its own param struct.
 		 */
 		child_main(mgt_param.sigsegv_handler,
 		    mgt_param.wthread_stacksize);

bin/varnishd/mgt/mgt_main.c

@@ -74,7 +74,7 @@ static char		*workdir;
 
 static struct vfil_path *vcl_path = NULL;
 
-static const char opt_spec[] = "?a:b:Cdf:Fh:i:I:j:l:M:n:P:p:r:S:s:T:t:VW:x:";
+static const char opt_spec[] = "?a:b:CdE:f:Fh:i:I:j:l:M:n:P:p:r:S:s:T:t:VW:x:";
 
 /*--------------------------------------------------------------------*/
 
@@ -123,6 +123,7 @@ usage(void)
 	printf(FMT, "-P file", "PID file");
 	printf(FMT, "-i identity", "Identity of varnish instance");
 	printf(FMT, "-I clifile", "Initialization CLI commands");
+	printf(FMT, "-E extension", "Load extension");
 
 	printf("\nTuning options:\n");
 
@@ -284,7 +285,9 @@ mgt_Cflag_atexit(void)
 	/* Only master process */
 	if (getpid() != heritage.mgt_pid)
 		return;
+	vext_cleanup();
 	VJ_rmdir("vmod_cache");
+	VJ_rmdir("vext_cache");
 	(void)chdir("/");
 	VJ_rmdir(workdir);
 }
@@ -660,6 +663,7 @@ main(int argc, char * const *argv)
 			W_arg = optarg;
 			break;
 		case 'a':
+		case 'E':
 		case 'f':
 		case 'I':
 		case 'p':
@@ -752,6 +756,9 @@ main(int argc, char * const *argv)
 			if (*alp->val != '\0')
 				alp->priv = mgt_f_read(alp->val);
 			break;
+		case 'E':
+			vext_argument(alp->val);
+			break;
 		case 'I':
 			VJ_master(JAIL_MASTER_FILE);
 			I_fd = open(alp->val, O_RDONLY);
@@ -821,6 +828,7 @@ main(int argc, char * const *argv)
 
 	VJ_master(JAIL_MASTER_SYSTEM);
 	AZ(system("rm -rf vmod_cache"));
+	AZ(system("rm -rf vext_cache"));
 	VJ_master(JAIL_MASTER_LOW);
 
 	if (VJ_make_subdir("vmod_cache", "VMOD cache", NULL)) {
@@ -829,6 +837,13 @@ main(int argc, char * const *argv)
 		    workdir, VAS_errtxt(errno));
 	}
 
+	if (arg_list_count("E") &&
+	    VJ_make_subdir("vext_cache", "VMOD cache", NULL)) {
+		ARGV_ERR(
+		    "Cannot create vmod directory (%s/vext_cache): %s\n",
+		    workdir, VAS_errtxt(errno));
+	}
+
 	if (C_flag)
 		AZ(atexit(mgt_Cflag_atexit));
 
@@ -881,6 +896,8 @@ main(int argc, char * const *argv)
 			VPF_Write(alp->priv);
 	}
 
+	vext_copyin(vident);
+
 	AZ(VSB_finish(vident));
 
 	if (S_arg == NULL)
@@ -968,6 +985,10 @@ main(int argc, char * const *argv)
 	MGT_Complain(C_INFO, "manager dies");
 	mgt_cli_close_all();
 	VEV_Destroy(&mgt_evb);
+	VJ_master(JAIL_MASTER_SYSTEM);
+	vext_cleanup();
+	(void)rmdir("vext_cache");
+	VJ_master(JAIL_MASTER_LOW);
 	VTAILQ_FOREACH(alp, &arglist, list) {
 		if (!strcmp(alp->arg, "P"))
 			VPF_Remove(alp->priv);