Module Name: src
Committed By: rillig
Date: Sat Feb 13 09:28:27 UTC 2021
Modified Files:
src/tests/lib/libcurses/slave: slave.c
Log Message:
tests/libcurses: fix reading from the parent process
In case of a short read, processing the incomplete data invoked
undefined behavior.
To generate a diff of this commit:
cvs rdiff -u -r1.14 -r1.15 src/tests/lib/libcurses/slave/slave.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/tests/lib/libcurses/slave/slave.c
diff -u src/tests/lib/libcurses/slave/slave.c:1.14 src/tests/lib/libcurses/slave/slave.c:1.15
--- src/tests/lib/libcurses/slave/slave.c:1.14 Sat Feb 13 09:18:12 2021
+++ src/tests/lib/libcurses/slave/slave.c Sat Feb 13 09:28:27 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: slave.c,v 1.14 2021/02/13 09:18:12 rillig Exp $ */
+/* $NetBSD: slave.c,v 1.15 2021/02/13 09:28:27 rillig Exp $ */
/*-
* Copyright 2009 Brett Lymn <[email protected]>
@@ -32,6 +32,7 @@
#include <sys/ioctl.h>
#include <unistd.h>
#include <err.h>
+#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@@ -50,6 +51,31 @@ static const char *returns_enum_names[]
};
#endif
+static bool
+try_read_from_director(void *data, size_t n)
+{
+ ssize_t nread = read(from_director, data, n);
+ if (nread < 0)
+ err(2, "error reading from command pipe");
+ if (nread == 0)
+ return false;
+ if ((size_t)nread != n)
+ errx(2, "short read from command pipe: expected %zu, got %zu",
+ n, (size_t)nread);
+ return true;
+}
+
+static void
+read_from_director(void *data, size_t n)
+{
+ ssize_t nread = read(from_director, data, n);
+ if (nread < 0)
+ err(2, "error reading from command pipe");
+ if ((size_t)nread != n)
+ errx(2, "short read from command pipe: expected %zu, got %zu",
+ n, (size_t)nread);
+}
+
/*
* Read the command pipe for the function to execute, gather the args
* and then process the command.
@@ -59,23 +85,16 @@ process_commands(void)
{
int len, maxlen, argslen, i, ret, type;
char *cmdbuf, *tmpbuf, **args, **tmpargs;
- ssize_t nread;
len = maxlen = 30;
if ((cmdbuf = malloc(maxlen)) == NULL)
err(1, "slave cmdbuf malloc failed");
- for (;;) {
- if ((nread = read(from_director, &type, sizeof(int))) < 0)
- err(1, "slave command type read failed");
- if (nread == 0)
- break;
-
+ while (try_read_from_director(&type, sizeof type)) {
if (type != data_string)
errx(1, "Unexpected type for command, got %d", type);
- if (read(from_director, &len, sizeof(int)) < 0)
- err(1, "slave command len read failed");
+ read_from_director(&len, sizeof len);
if ((len + 1) > maxlen) {
maxlen = len + 1;
@@ -85,18 +104,14 @@ process_commands(void)
cmdbuf = tmpbuf;
}
- if (read(from_director, cmdbuf, len) < 0)
- err(1, "slave command read failed");
+ read_from_director(cmdbuf, len);
cmdbuf[len] = '\0';
argslen = 0;
args = NULL;
do {
- if (read(from_director, &type, sizeof(int)) < 0)
- err(1, "slave arg type read failed");
-
- if (read(from_director, &len, sizeof(int)) < 0)
- err(1, "slave arg len read failed");
+ read_from_director(&type, sizeof type);
+ read_from_director(&len, sizeof len);
if (len >= 0) {
tmpargs = realloc(args,
@@ -120,8 +135,7 @@ process_commands(void)
else
args[argslen][0] = '\0';
} else {
- read(from_director, args[argslen],
- len);
+ read_from_director(args[argslen], len);
if (type != data_byte)
args[argslen][len] = '\0';
