From: Quentin Monnet <quentin.monnet@netronome.com>
Date: Thu, 1 Mar 2018 20:20:09 -0800
Subject: tools: bpftool: support continuation lines in batch files
Patch-mainline: v4.17-rc1
Git-commit: 65d538dde625d93359ca4e33d2311f8598f423a6
References: bsc#1109837

Add support for continuation lines, such as in the following example:

    prog show
    prog dump xlated \
        id 1337 opcodes

This patch is based after the code for support for continuation lines
from file lib/utils.c from package iproute2.

"Lines" in error messages are renamed as "commands", as we count the
number of commands (but we ignore empty lines, comments, and do not add
continuation lines to the count).

Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 tools/bpf/bpftool/main.c |   36 ++++++++++++++++++++++++++++++++----
 1 file changed, 32 insertions(+), 4 deletions(-)

--- a/tools/bpf/bpftool/main.c
+++ b/tools/bpf/bpftool/main.c
@@ -46,6 +46,9 @@
 
 #include "main.h"
 
+#define BATCH_LINE_LEN_MAX 65536
+#define BATCH_ARG_NB_MAX 4096
+
 const char *bin_name;
 static int last_argc;
 static char **last_argv;
@@ -171,9 +174,9 @@ static const struct cmd cmds[] = {
 
 static int do_batch(int argc, char **argv)
 {
+	char buf[BATCH_LINE_LEN_MAX], contline[BATCH_LINE_LEN_MAX];
+	char *n_argv[BATCH_ARG_NB_MAX];
 	unsigned int lines = 0;
-	char *n_argv[4096];
-	char buf[65536];
 	int n_argc;
 	FILE *fp;
 	char *cp;
@@ -210,13 +213,38 @@ static int do_batch(int argc, char **arg
 			break;
 		}
 
+		/* Append continuation lines if any (coming after a line ending
+		 * with '\' in the batch file).
+		 */
+		while ((cp = strstr(buf, "\\\n")) != NULL) {
+			if (!fgets(contline, sizeof(contline), fp) ||
+			    strlen(contline) == 0) {
+				p_err("missing continuation line on command %d",
+				      lines);
+				err = -1;
+				goto err_close;
+			}
+
+			cp = strchr(contline, '#');
+			if (cp)
+				*cp = '\0';
+
+			if (strlen(buf) + strlen(contline) + 1 > sizeof(buf)) {
+				p_err("command %d is too long", lines);
+				err = -1;
+				goto err_close;
+			}
+			buf[strlen(buf) - 2] = '\0';
+			strcat(buf, contline);
+		}
+
 		n_argc = 0;
 		n_argv[n_argc] = strtok(buf, " \t\n");
 
 		while (n_argv[n_argc]) {
 			n_argc++;
 			if (n_argc == ARRAY_SIZE(n_argv)) {
-				p_err("line %d has too many arguments, skip",
+				p_err("command %d has too many arguments, skip",
 				      lines);
 				n_argc = 0;
 				break;
@@ -252,7 +280,7 @@ static int do_batch(int argc, char **arg
 		p_err("reading batch file failed: %s", strerror(errno));
 		err = -1;
 	} else {
-		p_info("processed %d lines", lines);
+		p_info("processed %d commands", lines);
 		err = 0;
 	}
 err_close: