From: Martin Lucina <martin@lucina.net>
Date: Mon, 26 Jan 2015 11:40:11 +0000 (+0100)
Subject: rumprun, rumpconfig: Add support for setting guest environment.
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=1a5460b8ac3941c3b67535d3ce44d8b9108582f2;p=rumpuser-xen.git

rumprun, rumpconfig: Add support for setting guest environment.

Signed-off-by: Martin Lucina <martin@lucina.net>
---

diff --git a/app-tools/rumprun b/app-tools/rumprun
index 2bdf6f3..889bd57 100755
--- a/app-tools/rumprun
+++ b/app-tools/rumprun
@@ -35,7 +35,7 @@ err() {
 
 usage() {
 	cat <<EOM
-usage: rumprun STACK [ -ipd ] [ -D PORT ] [ -N NAME ] [ -M MEM ] [ -b BLKSPEC ] [ -n NETSPEC ] [ -- ] APP [ args ]
+usage: rumprun STACK [ -ipd ] [ -D PORT ] [ -N NAME ] [ -M MEM ] [ -b BLKSPEC ] [ -n NETSPEC ] [ -e VAR[=VALUE] ] [ -- ] APP [ args ]
     STACK is the rumprun stack to use. Only "xen" is currently supported
     APP is the rumprun application to start
     args will be passed to the application command line
@@ -45,6 +45,7 @@ usage: rumprun STACK [ -ipd ] [ -D PORT ] [ -N NAME ] [ -M MEM ] [ -b BLKSPEC ]
     -n NETSPEC configures a network interface, using one of:
        inet,dhcp - IPv4 with DHCP
        inet,static,ADDR/MASK[,GATEWAY] - IPv4 with static IP
+    -e set guest environment VAR to VALUE
     -i attaches to domain console on startup
     -p creates the domain but leaves it paused
     -d destroys the domain on poweroff
@@ -143,7 +144,7 @@ run_xen() {
 	opt_name=
 	opt_debug=
 	sudo=''
-	while getopts "n:b:pidD:N:M:" opt; do
+	while getopts "n:b:e:pidD:N:M:" opt; do
 		case "$opt" in
 			# -n: NETSPEC
 			n)
@@ -168,6 +169,21 @@ run_xen() {
 					>>${xenstore}
 				bindex=$(expr $bindex + 1)
 				;;
+			# -e: Set guest environment variable.
+			e)
+				case "${OPTARG}" in
+					*=*)
+						key=${OPTARG%%=*}
+						value=${OPTARG#*=}
+						;;
+					*)
+						key=${OPTARG}
+						value=
+						;;
+				esac
+				[ -n "$key" ] || usage
+				echo environ/${key} "${value}" >>${xenstore}
+				;;
 			# -p: Leave the domain paused after creation.
 			p)
 				opt_pause=1
@@ -237,8 +253,8 @@ EOM
 	domid=$(${sudo} xl domid ${name})
 	# Write provisioning information for domain to xenstore.
 	prefix=/local/domain/${domid}/rumprun
-	cat ${xenstore} | while read line; do
-		xenstore-write ${prefix}/${line}
+	cat ${xenstore} | while read key value; do
+		xenstore-write "${prefix}/${key}" "${value}"
 	done
 	rm ${xenstore}
 	# Attach debugger if requested.
diff --git a/rumpconfig.c b/rumpconfig.c
index cec6a5d..3c55fc4 100644
--- a/rumpconfig.c
+++ b/rumpconfig.c
@@ -410,13 +410,66 @@ out:
 	free(blk_fstype);
 }
 
+static int
+xs_read_environ(const char *name, char **value_out)
+{
+	char *value = NULL;
+	char buf[128];
+	char *xberr = NULL;
+	xenbus_transaction_t txn;
+	int xbretry = 0;
+
+	xberr = xenbus_transaction_start(&txn);
+	if (xberr) {
+		warnx("rumprun_config: xenbus_transaction_start() failed: %s",
+			xberr);
+		return 1;
+	}
+	snprintf(buf, sizeof buf, "rumprun/environ/%s", name);
+	xberr = xenbus_read(txn, buf, &value);
+	if (xberr) {
+		warnx("rumprun_config: environ: read %s failed: %s",
+			buf, xberr);
+		xenbus_transaction_end(txn, 0, &xbretry);
+		return 1;
+	}
+	xberr = xenbus_transaction_end(txn, 0, &xbretry);
+	if (xberr) {
+		warnx("rumprun_config: xenbus_transaction_end() failed: %s",
+			xberr);
+		free(value);
+		return 1;
+	}
+	*value_out = value;
+	return 0;
+}
+
+static void
+rumprun_config_environ(const char *name)
+{
+	char *value = NULL;
+	int rv;
+
+	rv = xs_read_environ(name, &value);
+	if (rv != 0)
+		return;
+	if (setenv(name, value, 1) != 0) {
+		warnx("rumprun_config: setenv(%s) failed: %d", errno);
+		goto out;
+	}
+
+out:
+	free(value);
+}
+
 void
 _rumprun_config(void)
 {
 	char *err = NULL;
 	xenbus_transaction_t txn;
 	char **netdevices = NULL,
-	     **blkdevices = NULL;
+	     **blkdevices = NULL,
+	     **environ = NULL;
 	int retry = 0,
 	    i;
 
@@ -438,6 +491,13 @@ _rumprun_config(void)
 		xenbus_transaction_end(txn, 0, &retry);
 		goto out_err;
 	}
+	err = xenbus_ls(txn, "rumprun/environ", &environ);
+	if (err && strcmp(err, "ENOENT") != 0) {
+		warnx("rumprun_config: xenbus_ls(rumprun/environ) failed: %s",
+				err);
+		xenbus_transaction_end(txn, 0, &retry);
+		goto out_err;
+	}
 	err = xenbus_transaction_end(txn, 0, &retry);
 	if (err) {
 		warnx("rumprun_config: xenbus_transaction_end() failed: %s",
@@ -458,6 +518,13 @@ _rumprun_config(void)
 		}
 		free(blkdevices);
 	}
+	if (environ) {
+		for(i = 0; environ[i]; i++) {
+			rumprun_config_environ(environ[i]);
+			free(environ[i]);
+		}
+		free(environ);
+	}
 	return;
 
 out_err:
@@ -471,6 +538,11 @@ out_err:
 			free(blkdevices[i]);
 		free(blkdevices);
 	}
+	if (environ) {
+		for(i = 0; environ[i]; i++)
+			free(environ[i]);
+		free(environ);
+	}
 }
 
 void
diff --git a/tests/hello/hello.c b/tests/hello/hello.c
index 4859dbb..3d97396 100644
--- a/tests/hello/hello.c
+++ b/tests/hello/hello.c
@@ -1,8 +1,13 @@
 #include <stdio.h>
+#include <stdlib.h>
 
 int main (int argc, char *argv[])
 {
-    printf ("Hello, world!\n");
+    char *world = getenv ("WORLD");
+    if (world)
+        printf ("Hello, %s!\n", world);
+    else
+        printf ("Hello, world!\n");
     printf ("Sleeping 5s...\n");
     sleep (5);
     printf ("Goodbye, world!\n");