Changeset 4e6a610 in mainline for uspace/lib/posix/src

Timestamp:

2018-06-25T09:54:28Z (7 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

bfe90b6

Parents:

fb0ec570

git-author:

Jiri Svoboda <jiri@…> (2018-06-24 17:51:54)

git-committer:

Jiri Svoboda <jiri@…> (2018-06-25 09:54:28)

Message:

Temporary file functions rework. Fix libposix access() not working on directories.

Location:

uspace/lib/posix/src

Files:

• stdio.c (modified) (4 diffs)
• stdlib.c (modified) (4 diffs)
• unistd.c (modified) (2 diffs)

uspace/lib/posix/src/stdio.c

@@ -2 +2 @@
  * Copyright (c) 2011 Jiri Zarevucky
  * Copyright (c) 2011 Petr Koupy
+ * Copyright (c) 2018 Jiri Svoboda
  * All rights reserved.
  *
@@ -38 +39 @@
 
 #include <assert.h>
-
 #include <errno.h>
-
+#include <stdbool.h>
+#include <tmpfile.h>
+
+#include "posix/fcntl.h"
 #include "posix/stdlib.h"
 #include "posix/string.h"
+#include "posix/sys/stat.h"
 #include "posix/sys/types.h"
 #include "posix/unistd.h"
@@ -353 +357 @@
 }
 
-/**
- * Get a unique temporary file name (obsolete).
- *
- * @param s Buffer for the file name. Must be at least L_tmpnam bytes long.
- * @return The value of s on success, NULL on failure.
- */
-char *tmpnam(char *s)
-{
-        assert(L_tmpnam >= strlen("/tmp/tnXXXXXX"));
-
-        static char buffer[L_tmpnam + 1];
-        if (s == NULL) {
-                s = buffer;
-        }
-
-        strcpy(s, "/tmp/tnXXXXXX");
-        mktemp(s);
-
-        if (*s == '\0') {
-                /* Errno set by mktemp(). */
-                return NULL;
-        }
-
-        return s;
-}
-
-/**
- * Get an unique temporary file name with additional constraints (obsolete).
+/** Determine if directory is an 'appropriate' temporary directory.
+ *
+ * @param dir Directory path
+ * @return @c true iff directory is appropriate.
+ */
+static bool is_appropriate_tmpdir(const char *dir)
+{
+        struct stat sbuf;
+
+        /* Must not be NULL */
+        if (dir == NULL)
+                return false;
+
+        /* Must not be empty */
+        if (dir[0] == '\0')
+                return false;
+
+        if (stat(dir, &sbuf) != 0)
+                return false;
+
+        /* Must be a directory */
+        if ((sbuf.st_mode & S_IFMT) != S_IFDIR)
+                return false;
+
+        /* Must be writable */
+        if (access(dir, W_OK) != 0)
+                return false;
+
+        return true;
+}
+
+/** Construct unique file name.
+ *
+ * Never use this function.
  *
  * @param dir Path to directory, where the file should be created.
@@ -388 +398 @@
 char *tempnam(const char *dir, const char *pfx)
 {
-        /* Sequence number of the filename. */
-        static int seq = 0;
-
-        size_t dir_len = strlen(dir);
-        if (dir[dir_len - 1] == '/') {
-                dir_len--;
-        }
-
-        size_t pfx_len = strlen(pfx);
-        if (pfx_len > 5) {
-                pfx_len = 5;
-        }
-
-        char *result = malloc(dir_len + /* slash*/ 1 +
-            pfx_len + /* three-digit seq */ 3 + /* .tmp */ 4 + /* nul */ 1);
-
-        if (result == NULL) {
-                errno = ENOMEM;
+        const char *dpref;
+        char *d;
+        char *buf;
+        int rc;
+
+        d = getenv("TMPDIR");
+        if (is_appropriate_tmpdir(d))
+                dpref = d;
+        else if (is_appropriate_tmpdir(dir))
+                dpref = dir;
+        else if (is_appropriate_tmpdir(P_tmpdir))
+                dpref = P_tmpdir;
+        else
+                dpref = "/";
+
+        if (dpref[strlen(dpref) - 1] != '/')
+                rc = asprintf(&buf, "%s/%sXXXXXX", dpref, pfx);
+        else
+                rc = asprintf(&buf, "%s%sXXXXXX", dpref, pfx);
+
+        if (rc < 0)
+                return NULL;
+
+        rc = __tmpfile_templ(buf, false);
+        if (rc != 0) {
+                free(buf);
                 return NULL;
         }
 
-        char *res_ptr = result;
-        strncpy(res_ptr, dir, dir_len);
-        res_ptr += dir_len;
-        strncpy(res_ptr, pfx, pfx_len);
-        res_ptr += pfx_len;
-
-        for (; seq < 1000; ++seq) {
-                snprintf(res_ptr, 8, "%03d.tmp", seq);
-
-                int orig_errno = errno;
-                errno = EOK;
-                /* Check if the file exists. */
-                if (access(result, F_OK) == -1) {
-                        if (errno == ENOENT) {
-                                errno = orig_errno;
-                                break;
-                        } else {
-                                /* errno set by access() */
-                                return NULL;
-                        }
-                }
-        }
-
-        if (seq == 1000) {
-                free(result);
-                errno = EINVAL;
-                return NULL;
-        }
-
-        return result;
-}
-
-/**
- * Create and open an unique temporary file.
- * The file is automatically removed when the stream is closed.
- *
- * @param dir Path to directory, where the file should be created.
- * @param pfx Optional prefix up to 5 characters long.
- * @return Newly allocated unique path for temporary file. NULL on failure.
- */
-FILE *tmpfile(void)
-{
-        char filename[] = "/tmp/tfXXXXXX";
-        int fd = mkstemp(filename);
-        if (fd == -1) {
-                /* errno set by mkstemp(). */
-                return NULL;
-        }
-
-        /* Unlink the created file, so that it's removed on close(). */
-        unlink(filename);
-        return fdopen(fd, "w+");
+        return buf;
 }
 

uspace/lib/posix/src/stdlib.c

@@ -38 +38 @@
 
 #include <errno.h>
+#include <tmpfile.h>
 
 #include "posix/fcntl.h"
@@ -163 +164 @@
 int mkstemp(char *tmpl)
 {
-        int fd = -1;
-
-        char *tptr = tmpl + strlen(tmpl) - 6;
-
-        while (fd < 0) {
-                if (*mktemp(tmpl) == '\0') {
-                        /* Errno set by mktemp(). */
-                        return -1;
-                }
-
-                fd = open(tmpl, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
-
-                if (fd == -1) {
-                        /* Restore template to it's original state. */
-                        snprintf(tptr, 7, "XXXXXX");
-                }
-        }
-
-        return fd;
+        int tmpl_len;
+        int file;
+
+        tmpl_len = strlen(tmpl);
+        if (tmpl_len < 6) {
+                errno = EINVAL;
+                return -1;
+        }
+
+        char *tptr = tmpl + tmpl_len - 6;
+        if (strcmp(tptr, "XXXXXX") != 0) {
+                errno = EINVAL;
+                return -1;
+        }
+
+        file = __tmpfile_templ(tmpl, true);
+        if (file < 0) {
+                errno = EIO; // XXX could be more specific
+                return -1;
+        }
+
+        return file;
 }
 
@@ -194 +198 @@
 char *mktemp(char *tmpl)
 {
-        int tmpl_len = strlen(tmpl);
+        int tmpl_len;
+        int rc;
+
+        tmpl_len = strlen(tmpl);
         if (tmpl_len < 6) {
                 errno = EINVAL;
@@ -208 +215 @@
         }
 
-        static int seq = 0;
-
-        for (; seq < 1000000; ++seq) {
-                snprintf(tptr, 7, "%06d", seq);
-
-                int orig_errno = errno;
-                errno = 0;
-                /* Check if the file exists. */
-                if (access(tmpl, F_OK) == -1) {
-                        if (errno == ENOENT) {
-                                errno = orig_errno;
-                                break;
-                        } else {
-                                /* errno set by access() */
-                                *tmpl = '\0';
-                                return tmpl;
-                        }
-                }
-        }
-
-        if (seq == 10000000) {
-                errno = EEXIST;
+        rc = __tmpfile_templ(tmpl, false);
+        if (rc != 0) {
+                errno = EIO; // XXX could be more specific
                 *tmpl = '\0';
                 return tmpl;

uspace/lib/posix/src/unistd.c

@@ -39 +39 @@
 #include <errno.h>
 
+#include "posix/dirent.h"
 #include "posix/string.h"
+#include "posix/sys/types.h"
 #include "posix/fcntl.h"
 
@@ -368 +370 @@
                  */
                 int fd = open(path, O_RDONLY);
-                if (fd < 0)
-                        return -1;
-                close(fd);
-                return 0;
+                if (fd >= 0) {
+                        close(fd);
+                        return 0;
+                }
+                DIR *dir = opendir(path);
+                if (dir != NULL) {
+                        closedir(dir);
+                        return 0;
+                }
+                return -1;
         } else {
                 /* Invalid amode argument. */