libbb: added xfdopen_for_read/write

function                                             old     new   delta
xfdopen_helper                                         -      40     +40
logdir_open                                         1163    1184     +21
process_stdin                                        433     443     +10
xfdopen_for_write                                      -       9      +9
doCommands                                          2465    2474      +9
patch_main                                          1214    1222      +8
bbunpack                                             457     465      +8
xfdopen_for_read                                       -       7      +7
scan_tree                                            258     262      +4
xstrtoul_range_sfx                                   230     231      +1
sendmail_main                                        957     955      -2
passwd_main                                         1027    1023      -4
parse                                                969     964      -5
test_main                                            253     247      -6
sed_main                                             655     649      -6
dos2unix_main                                        437     429      -8
fbsplash_main                                        950     938     -12
handle_dir_common                                    371     354     -17
expand_vars_to_list                                 2197    2169     -28
update_passwd                                       1275    1246     -29
------------------------------------------------------------------------------
(add/remove: 3/0 grow/shrink: 7/10 up/down: 117/-117)           Total: 0 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

15 files changed, 51 insertions, 49 deletions

diff --git a/coreutils/dos2unix.c b/coreutils/dos2unix.c
index 309cbc3..baf879e 100644
--- a/coreutils/dos2unix.c
+++ b/coreutils/dos2unix.c
@@ -42,10 +42,10 @@ static void convert(char *fn, int conv_type)
 		i = mkstemp(temp_fn);
 		if (i == -1
 		 || fchmod(i, st.st_mode) == -1
-		 || !(out = fdopen(i, "w+"))
 		) {
 			bb_simple_perror_msg_and_die(temp_fn);
 		}
+		out = xfdopen_for_write(i);
 	}
 
 	while ((i = fgetc(in)) != EOF) {
diff --git a/e2fsprogs/old_e2fsprogs/blkid/read.c b/e2fsprogs/old_e2fsprogs/blkid/read.c
index 67bc8ee..f795a5d 100644
--- a/e2fsprogs/old_e2fsprogs/blkid/read.c
+++ b/e2fsprogs/old_e2fsprogs/blkid/read.c
@@ -374,9 +374,7 @@ void blkid_read_cache(blkid_cache cache)
 	DBG(DEBUG_CACHE, printf("reading cache file %s\n",
 				cache->bic_filename));
 
-	file = fdopen(fd, "r");
-	if (!file)
-		goto errout;
+	file = xfdopen_for_read(fd);
 
 	while (fgets(buf, sizeof(buf), file)) {
 		blkid_dev dev;
diff --git a/e2fsprogs/old_e2fsprogs/blkid/save.c b/e2fsprogs/old_e2fsprogs/blkid/save.c
index 3600260..e60cca4 100644
--- a/e2fsprogs/old_e2fsprogs/blkid/save.c
+++ b/e2fsprogs/old_e2fsprogs/blkid/save.c
@@ -95,7 +95,7 @@ int blkid_flush_cache(blkid_cache cache)
 		sprintf(tmp, "%s-XXXXXX", filename);
 		fd = mkstemp(tmp);
 		if (fd >= 0) {
-			file = fdopen(fd, "w");
+			file = xfdopen_for_write(fd);
 			opened = tmp;
 		}
 		fchmod(fd, 0644);
diff --git a/editors/sed.c b/editors/sed.c
index c1ee750..19e7683 100644
--- a/editors/sed.c
+++ b/editors/sed.c
@@ -1338,7 +1338,7 @@ int sed_main(int argc UNUSED_PARAM, char **argv)
 			nonstdoutfd = mkstemp(G.outname);
 			if (-1 == nonstdoutfd)
 				bb_perror_msg_and_die("can't create temp file %s", G.outname);
-			G.nonstdout = fdopen(nonstdoutfd, "w");
+			G.nonstdout = xfdopen_for_write(nonstdoutfd);
 
 			/* Set permissions/owner of output file */
 			fstat(fileno(file), &statbuf);
diff --git a/include/libbb.h b/include/libbb.h
index 89d7a7b..d95be5c 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -658,21 +658,23 @@ extern char *xmalloc_fgetline(FILE *file) FAST_FUNC RETURNS_MALLOC;
 /* Same, but doesn't try to conserve space (may have some slack after the end) */
 /* extern char *xmalloc_fgetline_fast(FILE *file) FAST_FUNC RETURNS_MALLOC; */
 
-extern void die_if_ferror(FILE *file, const char *msg) FAST_FUNC;
-extern void die_if_ferror_stdout(void) FAST_FUNC;
-extern int fflush_all(void) FAST_FUNC;
-extern void fflush_stdout_and_exit(int retval) NORETURN FAST_FUNC;
-extern int fclose_if_not_stdin(FILE *file) FAST_FUNC;
-extern FILE *xfopen(const char *filename, const char *mode) FAST_FUNC;
+void die_if_ferror(FILE *file, const char *msg) FAST_FUNC;
+void die_if_ferror_stdout(void) FAST_FUNC;
+int fflush_all(void) FAST_FUNC;
+void fflush_stdout_and_exit(int retval) NORETURN FAST_FUNC;
+int fclose_if_not_stdin(FILE *file) FAST_FUNC;
+FILE* xfopen(const char *filename, const char *mode) FAST_FUNC;
 /* Prints warning to stderr and returns NULL on failure: */
-extern FILE *fopen_or_warn(const char *filename, const char *mode) FAST_FUNC;
+FILE* fopen_or_warn(const char *filename, const char *mode) FAST_FUNC;
 /* "Opens" stdin if filename is special, else just opens file: */
-extern FILE *xfopen_stdin(const char *filename) FAST_FUNC;
-extern FILE *fopen_or_warn_stdin(const char *filename) FAST_FUNC;
-extern FILE* fopen_for_read(const char *path) FAST_FUNC;
-extern FILE* xfopen_for_read(const char *path) FAST_FUNC;
-extern FILE* fopen_for_write(const char *path) FAST_FUNC;
-extern FILE* xfopen_for_write(const char *path) FAST_FUNC;
+FILE* xfopen_stdin(const char *filename) FAST_FUNC;
+FILE* fopen_or_warn_stdin(const char *filename) FAST_FUNC;
+FILE* fopen_for_read(const char *path) FAST_FUNC;
+FILE* xfopen_for_read(const char *path) FAST_FUNC;
+FILE* fopen_for_write(const char *path) FAST_FUNC;
+FILE* xfopen_for_write(const char *path) FAST_FUNC;
+FILE* xfdopen_for_read(int fd) FAST_FUNC;
+FILE* xfdopen_for_write(int fd) FAST_FUNC;
 
 int bb_pstrcmp(const void *a, const void *b) /* not FAST_FUNC! */;
 void qsort_string_vector(char **sv, unsigned count) FAST_FUNC;
diff --git a/libbb/update_passwd.c b/libbb/update_passwd.c
index ba773fc..301893b 100644
--- a/libbb/update_passwd.c
+++ b/libbb/update_passwd.c
@@ -137,12 +137,7 @@ int FAST_FUNC update_passwd(const char *filename,
 		fchown(new_fd, sb.st_uid, sb.st_gid);
 	}
 	errno = 0;
-	new_fp = fdopen(new_fd, "w");
-	if (!new_fp) {
-		bb_perror_nomsg();
-		close(new_fd);
-		goto unlink_new;
-	}
+	new_fp = xfdopen_for_write(new_fd);
 
 	/* Backup file is "/etc/passwd-" */
 	*sfx_char = '-';
diff --git a/libbb/wfopen.c b/libbb/wfopen.c
index 1cb871e..deec79a 100644
--- a/libbb/wfopen.c
+++ b/libbb/wfopen.c
@@ -38,3 +38,19 @@ FILE* FAST_FUNC xfopen_for_write(const char *path)
 {
 	return xfopen(path, "w");
 }
+
+static FILE* xfdopen_helper(unsigned fd_and_rw_bit)
+{
+	FILE* fp = fdopen(fd_and_rw_bit >> 1, fd_and_rw_bit & 1 ? "w" : "r");
+	if (!fp)
+		bb_error_msg_and_die(bb_msg_memory_exhausted);
+	return fp;
+}
+FILE* FAST_FUNC xfdopen_for_read(int fd)
+{
+	return xfdopen_helper(fd << 1);
+}
+FILE* FAST_FUNC xfdopen_for_write(int fd)
+{
+	return xfdopen_helper((fd << 1) + 1);
+}
diff --git a/mailutils/mime.c b/mailutils/mime.c
index dd81139..17d0f9d 100644
--- a/mailutils/mime.c
+++ b/mailutils/mime.c
@@ -293,7 +293,7 @@ static int parse(const char *boundary, char **argv)
 				}
 				// parent dumps to fd[1]
 				close(fd[0]);
-				fp = fdopen(fd[1], "w");
+				fp = xfdopen_for_write(fd[1]);
 				signal(SIGPIPE, SIG_IGN); // ignore EPIPE
 			// or create a file for dump
 			} else {
diff --git a/mailutils/sendmail.c b/mailutils/sendmail.c
index 2f99df6..4b58a78 100644
--- a/mailutils/sendmail.c
+++ b/mailutils/sendmail.c
@@ -93,7 +93,7 @@ int sendmail_main(int argc UNUSED_PARAM, char **argv)
 
 	// save initial stdin since body is piped!
 	xdup2(STDIN_FILENO, 3);
-	G.fp0 = fdopen(3, "r");
+	G.fp0 = xfdopen_for_read(3);
 
 	// parse options
 	// -f is required. -H and -S are mutually exclusive
diff --git a/miscutils/fbsplash.c b/miscutils/fbsplash.c
index 0afd189..4560bb2 100644
--- a/miscutils/fbsplash.c
+++ b/miscutils/fbsplash.c
@@ -227,7 +227,7 @@ static void fb_drawimage(void)
 		int fd = open_zipped(G.image_filename);
 		if (fd < 0)
 			bb_simple_perror_msg_and_die(G.image_filename);
-		theme_file = fdopen(fd, "r");
+		theme_file = xfdopen_for_read(fd);
 	}
 	head = xmalloc(256);
 
diff --git a/modutils/modprobe-small.c b/modutils/modprobe-small.c
index 8ef9101..53b7c94 100644
--- a/modutils/modprobe-small.c
+++ b/modutils/modprobe-small.c
@@ -384,11 +384,7 @@ static void write_out_dep_bb(int fd)
 	FILE *fp;
 
 	/* We want good error reporting. fdprintf is not good enough. */
-	fp = fdopen(fd, "w");
-	if (!fp) {
-		close(fd);
-		goto err;
-	}
+	fp = xfdopen_for_write(fd);
 	i = 0;
 	while (modinfo[i].pathname) {
 		fprintf(fp, "%s%s%s\n" "%s%s\n",
diff --git a/networking/ftpd.c b/networking/ftpd.c
index 9937cc3..df8188c 100644
--- a/networking/ftpd.c
+++ b/networking/ftpd.c
@@ -691,9 +691,7 @@ handle_dir_common(int opts)
 	/* -n prevents user/groupname display,
 	 * which can be problematic in chroot */
 	ls_fd = popen_ls((opts & LONG_LISTING) ? "-l" : "-1");
-	ls_fp = fdopen(ls_fd, "r");
-	if (!ls_fp) /* never happens. paranoia */
-		bb_perror_msg_and_die("fdopen");
+	ls_fp = xfdopen_for_read(ls_fd);
 
 	if (opts & USE_CTRL_CONN) {
 		/* STAT <filename> */
diff --git a/networking/ifupdown.c b/networking/ifupdown.c
index 88d1944..b16186e 100644
--- a/networking/ifupdown.c
+++ b/networking/ifupdown.c
@@ -1056,8 +1056,8 @@ static int popen2(FILE **in, FILE **out, char *command, char *param)
 	/* parent */
 	close(infd.rd);
 	close(outfd.wr);
-	*in = fdopen(infd.wr, "w");
-	*out = fdopen(outfd.rd, "r");
+	*in = xfdopen_for_write(infd.wr);
+	*out = xfdopen_for_read(outfd.rd);
 	return pid;
 }
 
diff --git a/runit/svlogd.c b/runit/svlogd.c
index 9a00fad..fe40cd8 100644
--- a/runit/svlogd.c
+++ b/runit/svlogd.c
@@ -761,8 +761,8 @@ static NOINLINE unsigned logdir_open(struct logdir *ld, const char *fn)
 	}
 	while ((ld->fdcur = open("current", O_WRONLY|O_NDELAY|O_APPEND|O_CREAT, 0600)) == -1)
 		pause2cannot("open current", ld->name);
-	/* we presume this cannot fail */
-	ld->filecur = fdopen(ld->fdcur, "a"); ////
+	while ((ld->filecur = fdopen(ld->fdcur, "a")) == NULL)
+		pause2cannot("open current", ld->name); ////
 	setvbuf(ld->filecur, NULL, _IOFBF, linelen); ////
 
 	close_on_exec_on(ld->fdcur);
diff --git a/shell/hush.c b/shell/hush.c
index 6f394d1..ede8d68 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -5301,25 +5301,22 @@ static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
 	free(to_free);
 # endif
 	close(channel[1]);
-//TODO: libbb: fdopen_or_die?
-	return fdopen(channel[0], "r");
+	close_on_exec_on(channel[0]);
+	return xfdopen_for_read(channel[0]);
 }
 
 /* Return code is exit status of the process that is run. */
 static int process_command_subs(o_string *dest, const char *s)
 {
-	FILE *pf;
+	FILE *fp;
 	struct in_str pipe_str;
 	pid_t pid;
 	int status, ch, eol_cnt;
 
-	pf = generate_stream_from_string(s, &pid);
-	if (pf == NULL)
-		return 1;
-	close_on_exec_on(fileno(pf));
+	fp = generate_stream_from_string(s, &pid);
 
 	/* Now send results of command back into original context */
-	setup_file_in_str(&pipe_str, pf);
+	setup_file_in_str(&pipe_str, fp);
 	eol_cnt = 0;
 	while ((ch = i_getch(&pipe_str)) != EOF) {
 		if (ch == '\n') {
@@ -5334,7 +5331,7 @@ static int process_command_subs(o_string *dest, const char *s)
 	}
 
 	debug_printf("done reading from `cmd` pipe, closing it\n");
-	fclose(pf);
+	fclose(fp);
 	/* We need to extract exitcode. Test case
 	 * "true; echo `sleep 1; false` $?"
 	 * should print 1 */