[src/trunk]: src/tests/lib/libcurses/slave tests/libcurses: protect against s...

[rillig <rillig%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/e42cc8a77dd8
branches:  trunk
changeset: 980654:e42cc8a77dd8
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sat Feb 13 19:23:11 2021 +0000

description:
tests/libcurses: protect against short writes

The previous code only errored out if a write failed completely.  If it
was partially written, the program continued without writing the rest of
it.

Extract the common code into a few functions that write raw data to the
parent process.

diffstat:

 tests/lib/libcurses/slave/commands.c |  150 ++++++++++++----------------------
 1 files changed, 53 insertions(+), 97 deletions(-)

diffs (236 lines):

diff -r c56346a5f7d5 -r e42cc8a77dd8 tests/lib/libcurses/slave/commands.c
--- a/tests/lib/libcurses/slave/commands.c      Sat Feb 13 18:24:11 2021 +0000
+++ b/tests/lib/libcurses/slave/commands.c      Sat Feb 13 19:23:11 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: commands.c,v 1.12 2021/02/13 08:14:46 rillig Exp $     */
+/*     $NetBSD: commands.c,v 1.13 2021/02/13 19:23:11 rillig Exp $     */
 
 /*-
  * Copyright 2009 Brett Lymn <blymn%NetBSD.org@localhost>
@@ -42,8 +42,7 @@
 
 extern int initdone;
 
-static void report_type(data_enum_t);
-static void report_message(int, const char *);
+static void report_message(data_enum_t, const char *);
 
 /*
  * Match the passed command string and execute the associated test
@@ -85,6 +84,29 @@
        report_status("UNKNOWN_FUNCTION");
 }
 
+static void
+write_to_director(const void *mem, size_t size)
+{
+       ssize_t nwritten = write(to_director, mem, size);
+       if (nwritten == -1)
+               err(1, "writing to director failed");
+       if ((size_t)nwritten != size)
+               err(1, "short write to director, expected %zu, got %zd",
+                   size, nwritten);
+}
+
+static void
+write_to_director_int(int i)
+{
+       write_to_director(&i, sizeof i);
+}
+
+static void
+write_to_director_type(data_enum_t return_type)
+{
+       write_to_director_int(return_type);
+}
+
 /*
  * Report an pointer value back to the director
  */
@@ -121,9 +143,9 @@
 report_return(int status)
 {
        if (status == ERR)
-               report_type(data_err);
+               write_to_director_type(data_err);
        else if (status == OK)
-               report_type(data_ok);
+               write_to_director_type(data_ok);
        else if (status == KEY_CODE_YES)
                report_int(status);
        else
@@ -131,33 +153,13 @@
 }
 
 /*
- * Report the type back to the director via the command pipe
- */
-static void
-report_type(data_enum_t return_type)
-{
-       int type;
-
-       type = return_type;
-       if (write(to_director, &type, sizeof(int)) < 0)
-               err(1, "command pipe write for status type failed");
-
-}
-
-/*
  * Report the number of returns back to the director via the command pipe
  */
 void
 report_count(int count)
 {
-       int type;
-
-       type = data_count;
-       if (write(to_director, &type, sizeof(int)) < 0)
-               err(1, "command pipe write for count type failed");
-
-       if (write(to_director, &count, sizeof(int)) < 0)
-               err(1, "command pipe write for count");
+       write_to_director_type(data_count);
+       write_to_director_int(count);
 }
 
 /*
@@ -183,20 +185,12 @@
  * command pipe.
  */
 static void
-report_message(int type, const char *status)
+report_message(data_enum_t type, const char *status)
 {
-       int len;
-
-       len = strlen(status);
-
-       if (write(to_director, &type, sizeof(int)) < 0)
-               err(1, "command pipe write for message type failed");
-
-       if (write(to_director, &len, sizeof(int)) < 0)
-               err(1, "command pipe write for message length failed");
-
-       if (write(to_director, status, len) < 0)
-               err(1, "command pipe write of message data failed");
+       size_t len = strlen(status);
+       write_to_director_type(type);
+       write_to_director_int(len);
+       write_to_director(status, len);
 }
 
 /*
@@ -218,31 +212,17 @@
 void
 report_nstr(chtype *string)
 {
-       int len, type;
+       size_t size;
        chtype *p;
 
-       len = 0;
-       p = string;
-
-       while ((*p++ & __CHARTEXT) != 0) {
-               len++;
-       }
-
-       len++; /* add in the termination chtype */
-       len *= sizeof(chtype);
+       for (p = string; (*p & __CHARTEXT) != 0; p++)
+               continue;
 
-       type = data_byte;
-       if (write(to_director, &type, sizeof(int)) < 0)
-               err(1, "%s: command pipe write for status type failed",
-                   __func__);
+       size = (size_t)(p + 1 - string) * sizeof *p;
 
-       if (write(to_director, &len, sizeof(int)) < 0)
-               err(1, "%s: command pipe write for status length failed",
-                   __func__);
-
-       if (write(to_director, string, len) < 0)
-               err(1, "%s: command pipe write of status data failed",
-                   __func__);
+       write_to_director_type(data_byte);
+       write_to_director_int(size);
+       write_to_director(string, size);
 }
 
 /*
@@ -251,21 +231,10 @@
 void
 report_cchar(cchar_t c)
 {
-       int len, type;
-       len = sizeof(cchar_t);
-       type = data_cchar;
 
-       if (write(to_director, &type, sizeof(int)) < 0)
-               err(1, "%s: command pipe write for status type failed",
-                   __func__);
-
-       if (write(to_director, &len, sizeof(int)) < 0)
-               err(1, "%s: command pipe write for status length failed",
-                   __func__);
-
-       if (write(to_director, &c, len) < 0)
-               err(1, "%s: command pipe write of status data failed",
-                   __func__);
+       write_to_director_type(data_cchar);
+       write_to_director_int(sizeof c);
+       write_to_director(&c, sizeof c);
 }
 
 /*
@@ -288,30 +257,17 @@
 void
 report_wstr(wchar_t *wstr)
 {
-       int len, type;
+       size_t size;
        wchar_t *p;
 
-       len = 0;
-       p = wstr;
-
-       while (*p++ != L'\0')
-               len++;
-
-       len++; /* add in the termination chtype */
-       len *= sizeof(wchar_t);
+       for (p = wstr; *p != L'\0'; p++)
+               continue;
+       size = (size_t)(p + 1 - wstr) * sizeof *p;
 
-       type = data_wchar;
-       if (write(to_director, &type, sizeof(int)) < 0)
-               err(1, "%s: command pipe write for status type failed",
-                   __func__);
 
-       if (write(to_director, &len, sizeof(int)) < 0)
-               err(1, "%s: command pipe write for status length failed",
-                   __func__);
-
-       if (write(to_director, wstr, len) < 0)
-               err(1, "%s: command pipe write of status data failed",
-                   __func__);
+       write_to_director_type(data_wchar);
+       write_to_director_int(size);
+       write_to_director(wstr, size);
 }
 
 /*
@@ -324,8 +280,8 @@
        if (nargs != expected) {
                report_count(1);
                report_error("INCORRECT_ARGUMENT_NUMBER");
-               return(1);
+               return 1;
        }
 
-       return(0);
+       return 0;
 }