Make pw(8) showuser work the same with or without -R <path> for non-root

[pw-darwin.git] / libutil / gr_util.c

diff --git a/libutil/gr_util.c b/libutil/gr_util.c
index 93b3eb2f92fc4d0693000bce7b875984e46ba0be..796cbf021ded95b1ccfb3e21b7dac366ae2bde23 100644 (file)
--- a/libutil/gr_util.c
+++ b/libutil/gr_util.c
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
  * Copyright (c) 2008 Sean C. Farley <scf@FreeBSD.org>
  * All rights reserved.
  *
@@ -141,7 +143,7 @@ gr_tmp(int mfd)
                errno = ENAMETOOLONG;
                return (-1);
        }
-       if ((tfd = mkostemp(tempname, O_SYNC)) == -1)
+       if ((tfd = mkostemp(tempname, 0)) == -1)
                return (-1);
        if (mfd != -1) {
                while ((nr = read(mfd, buf, sizeof(buf))) > 0)
@@ -164,11 +166,12 @@ gr_tmp(int mfd)
 int
 gr_copy(int ffd, int tfd, const struct group *gr, struct group *old_gr)
 {
-       char buf[8192], *end, *line, *p, *q, *r, t;
+       char *buf, *end, *line, *p, *q, *r, *tmp;
        struct group *fgr;
        const struct group *sgr;
-       size_t len;
+       size_t len, size;
        int eof, readlen;
+       char t;
 
        if (old_gr == NULL && gr == NULL)
                return(-1);
@@ -186,6 +189,10 @@ gr_copy(int ffd, int tfd, const struct group *gr, struct group *old_gr)
        if (sgr == NULL)
                sgr = gr;
 
+       /* initialize the buffer */
+       if ((buf = malloc(size = 1024)) == NULL)
+               goto err;
+
        eof = 0;
        len = 0;
        p = q = end = buf;
@@ -199,10 +206,16 @@ gr_copy(int ffd, int tfd, const struct group *gr, struct group *old_gr)
                if (q >= end) {
                        if (eof)
                                break;
-                       if ((size_t)(q - p) >= sizeof(buf)) {
-                               warnx("group line too long");
-                               errno = EINVAL; /* hack */
-                               goto err;
+                       while ((size_t)(q - p) >= size) {
+                               if ((tmp = reallocarray(buf, 2, size)) == NULL) {
+                                       warnx("group line too long");
+                                       goto err;
+                               }
+                               p = tmp + (p - buf);
+                               q = tmp + (q - buf);
+                               end = tmp + (end - buf);
+                               buf = tmp;
+                               size = size * 2;
                        }
                        if (p < end) {
                                q = memmove(buf, p, end -p);
@@ -210,7 +223,7 @@ gr_copy(int ffd, int tfd, const struct group *gr, struct group *old_gr)
                        } else {
                                p = q = end = buf;
                        }
-                       readlen = read(ffd, end, sizeof(buf) - (end -buf));
+                       readlen = read(ffd, end, size - (end - buf));
                        if (readlen == -1)
                                goto err;
                        else
@@ -219,7 +232,7 @@ gr_copy(int ffd, int tfd, const struct group *gr, struct group *old_gr)
                                break;
                        end += len;
                        len = end - buf;
-                       if (len < (ssize_t)sizeof(buf)) {
+                       if (len < size) {
                                eof = 1;
                                if (len > 0 && buf[len -1] != '\n')
                                        ++len, *end++ = '\n';
@@ -281,7 +294,7 @@ gr_copy(int ffd, int tfd, const struct group *gr, struct group *old_gr)
                        if (write(tfd, q, end - q) != end - q)
                                goto err;
                        q = buf;
-                       readlen = read(ffd, buf, sizeof(buf));
+                       readlen = read(ffd, buf, size);
                        if (readlen == 0)
                                break;
                        else
@@ -303,12 +316,12 @@ gr_copy(int ffd, int tfd, const struct group *gr, struct group *old_gr)
           write(tfd, "\n", 1) != 1)
                goto err;
  done:
-       if (line != NULL)
-               free(line);
+       free(line);
+       free(buf);
        return (0);
  err:
-       if (line != NULL)
-               free(line);
+       free(line);
+       free(buf);
        return (-1);
 }