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 309cbc3b8..baf879e54 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 67bc8ee44..f795a5d14 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 3600260e2..e60cca445 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 c1ee7502a..19e768355 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 89d7a7b1b..d95be5c51 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 ba773fcb2..301893be1 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 1cb871ef5..deec79a28 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 dd81139f2..17d0f9d80 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 2f99df6c0..4b58a78eb 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 0afd189ca..4560bb2e9 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 8ef9101e7..53b7c9468 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 9937cc3ea..df8188cba 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 88d1944da..b16186ec7 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 9a00fadee..fe40cd890 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 6f394d1d5..ede8d680e 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 */