From aa3fe79526bbce17f5ceec4d9c2d2246f01d6828 Mon Sep 17 00:00:00 2001
From: Andre Noll <maan@systemlinux.org>
Date: Thu, 5 Jan 2012 17:19:49 +0100
Subject: [PATCH] Pass command via sideband.

This makes para_cclient pass the paraslash command and its arguments
as a sideband packet to para_server if possible.

For sideband connections the command and its arguments are stored as
NULL-terminated strings. This is better than separating by newlines
(as we do for non-sideband connections) because it allows for arguments
containing newlines.

Suitable helpers for creating and parsing a buffer of NULL-terminated
strings, are provided in client_common.c and command.c, respectively.

No change for non-sideband connections.
---
 client_common.c | 27 +++++++++++++++++
 command.c       | 79 ++++++++++++++++++++++++++++++++++++++-----------
 2 files changed, 88 insertions(+), 18 deletions(-)

diff --git a/client_common.c b/client_common.c
index 53f7b5a9..ff351e89 100644
--- a/client_common.c
+++ b/client_common.c
@@ -245,6 +245,26 @@ static bool has_feature(const char *feature, struct client_task *ct)
 	return find_arg(feature, ct->features) >= 0? true : false;
 }
 
+static int send_sb_command(struct client_task *ct)
+{
+	int i;
+	char *command, *p;
+	size_t len = 0;
+
+	if (ct->sbc)
+		return send_sb(ct, NULL, 0, 0, false);
+
+	for (i = 0; i < ct->conf.inputs_num; i++)
+		len += strlen(ct->conf.inputs[i]) + 1;
+	p = command = para_malloc(len);
+	for (i = 0; i < ct->conf.inputs_num; i++) {
+		strcpy(p, ct->conf.inputs[i]);
+		p += strlen(ct->conf.inputs[i]) + 1;
+	}
+	PARA_DEBUG_LOG("--> %s\n", command);
+	return send_sb(ct, command, len, SBD_COMMAND, false);
+}
+
 /**
  * The post select hook for client commands.
  *
@@ -385,6 +405,13 @@ static void client_post_select(struct sched *s, struct task *t)
 		char *command = NULL;
 		if (!FD_ISSET(ct->scc.fd, &s->wfds))
 			return;
+		if (ct->use_sideband) {
+			ret = send_sb_command(ct);
+			if (ret <= 0)
+				goto out;
+			ct->status = CL_SENT_COMMAND;
+			return;
+		}
 		for (i = 0; i < ct->conf.inputs_num; i++) {
 			char *tmp = command;
 			command = make_message("%s\n%s", command?
diff --git a/command.c b/command.c
index 8deb69ce..c18cd4dd 100644
--- a/command.c
+++ b/command.c
@@ -856,6 +856,38 @@ out:
 
 #define HANDSHAKE_BUFSIZE 4096
 
+static int parse_sb_command(struct command_context *cc, struct iovec *iov)
+{
+	int ret, i;
+	char *p, *end;
+
+	ret = -E_BAD_CMD;
+	if (iov->iov_base == NULL || iov->iov_len == 0)
+		goto out;
+	p = iov->iov_base;
+	p[iov->iov_len - 1] = '\0'; /* just to be sure */
+	cc->cmd = get_cmd_ptr(p, NULL);
+	if (!cc->cmd)
+		goto out;
+	ret = check_perms(cc->u->perms, cc->cmd);
+	if (ret < 0)
+		goto out;
+	end = iov->iov_base + iov->iov_len;
+	for (i = 0, p = iov->iov_base; p < end; i++)
+		p += strlen(p) + 1;
+	cc->argc = i;
+	cc->argv = para_malloc((cc->argc + 1) * sizeof(char *));
+	for (i = 0, p = iov->iov_base; p < end; i++) {
+		cc->argv[i] = para_strdup(p);
+		p += strlen(p) + 1;
+	}
+	cc->argv[cc->argc] = NULL;
+	ret = cc->argc;
+out:
+	free(iov->iov_base);
+	return ret;
+}
+
 /**
  * Perform user authentication and execute a command.
  *
@@ -981,24 +1013,35 @@ __noreturn void handle_connect(int fd, const char *peername)
 		ret = sc_send_buffer(&cc->scc, PROCEED_MSG);
 	if (ret < 0)
 		goto net_err;
-	ret = read_command(&cc->scc, &command);
-	if (ret == -E_COMMAND_SYNTAX)
-		goto err_out;
-	if (ret < 0)
-		goto net_err;
-	ret = -E_BAD_CMD;
-	cc->cmd = parse_cmd(command);
-	if (!cc->cmd)
-		goto err_out;
-	/* valid command, check permissions */
-	ret = check_perms(cc->u->perms, cc->cmd);
-	if (ret < 0)
-		goto err_out;
-	/* valid command and sufficient perms */
-	ret = create_argv(command, "\n", &cc->argv);
-	if (ret < 0)
-		goto err_out;
-	cc->argc = ret;
+	if (cc->use_sideband) {
+		struct iovec iov;
+		ret = recv_sb(&cc->scc, SBD_COMMAND, MAX_COMMAND_LEN, &iov);
+		if (ret < 0)
+			goto net_err;
+		ret = parse_sb_command(cc, &iov);
+		if (ret < 0)
+			goto err_out;
+		cc->argc = ret;
+	} else {
+		ret = read_command(&cc->scc, &command);
+		if (ret == -E_COMMAND_SYNTAX)
+			goto err_out;
+		if (ret < 0)
+			goto net_err;
+		ret = -E_BAD_CMD;
+		cc->cmd = parse_cmd(command);
+		if (!cc->cmd)
+			goto err_out;
+		/* valid command, check permissions */
+		ret = check_perms(cc->u->perms, cc->cmd);
+		if (ret < 0)
+			goto err_out;
+		/* valid command and sufficient perms */
+		ret = create_argv(command, "\n", &cc->argv);
+		if (ret < 0)
+			goto err_out;
+		cc->argc = ret;
+	}
 	PARA_NOTICE_LOG("calling com_%s() for %s@%s\n", cc->cmd->name,
 		cc->u->name, peername);
 	ret = cc->cmd->handler(cc);
-- 
2.39.5