Allow opening symlinks r/w, but don't actually allow writing. Fixes test426

[netatalk.git] / libatalk / adouble / ad_write.c

diff --git a/libatalk/adouble/ad_write.c b/libatalk/adouble/ad_write.c
index f5c4eee8aa27908a0edd9f05cf8bd6d9f0211534..35ebc222675f33787ca59ced3e7214ab9624db6c 100644 (file)
--- a/libatalk/adouble/ad_write.c
+++ b/libatalk/adouble/ad_write.c
@@ -1,5 +1,5 @@
 /*
- * $Id: ad_write.c,v 1.7 2003-02-09 15:36:13 didg Exp $
+ * $Id: ad_write.c,v 1.11 2010-03-30 12:55:26 franklahm Exp $
  *
  * Copyright (c) 1990,1995 Regents of The University of Michigan.
  * All Rights Reserved.  See COPYRIGHT.
@@ -47,36 +47,36 @@ ssize_t adf_pwrite(struct ad_fd *ad_fd, const void *buf, size_t count, off_t off
 }
 
 /* end is always 0 */
-ssize_t ad_write( ad, eid, off, end, buf, buflen )
-    struct adouble     *ad;
-    const u_int32_t    eid;
-    off_t               off;
-    const int          end;
-    const char         *buf;
-    const size_t       buflen;
+ssize_t ad_write(struct adouble *ad, const u_int32_t eid, off_t off, const int end, const char *buf, const size_t buflen)
 {
     struct stat                st;
     ssize_t            cc;
+
+    if (ad_data_fileno(ad) == -2) {
+        /* It's a symlink */
+        errno = EACCES;
+        return -1;
+    }
     
     if ( eid == ADEID_DFORK ) {
        if ( end ) {
-           if ( fstat( ad->ad_df.adf_fd, &st ) < 0 ) {
+           if ( fstat( ad_data_fileno(ad), &st ) < 0 ) {
                return( -1 );
            }
            off = st.st_size - off;
        }
-       cc = adf_pwrite(&ad->ad_df, buf, buflen, off);
+       cc = adf_pwrite(&ad->ad_data_fork, buf, buflen, off);
     } else if ( eid == ADEID_RFORK ) {
         off_t    r_off;
 
        if ( end ) {
-           if ( fstat( ad->ad_df.adf_fd, &st ) < 0 ) {
+           if ( fstat( ad_data_fileno(ad), &st ) < 0 ) {
                return( -1 );
            }
            off = st.st_size - off -ad_getentryoff(ad, eid);
        }
        r_off = ad_getentryoff(ad, eid) + off;
-       cc = adf_pwrite(&ad->ad_hf, buf, buflen, r_off);
+       cc = adf_pwrite(&ad->ad_resource_fork, buf, buflen, r_off);
 
        /* sync up our internal buffer  FIXME always false? */
        if (r_off < ad_getentryoff(ad, ADEID_RFORK)) {
@@ -94,27 +94,77 @@ ssize_t ad_write( ad, eid, off, end, buf, buflen )
 
 /* 
  * the caller set the locks
- * we need tocopy and paste from samba code source/smbd/vfs_wrap.c
  * ftruncate is undefined when the file length is smaller than 'size'
  */
-int ad_rtruncate( ad, size )
-    struct adouble     *ad;
-    const off_t        size;
+int sys_ftruncate(int fd, off_t length)
 {
-    if ( ftruncate( ad->ad_hf.adf_fd,
+
+#ifndef  HAVE_PWRITE
+off_t           curpos;
+#endif
+int             err;
+struct stat    st;
+char            c = 0;
+
+    if (!ftruncate(fd, length)) {
+        return 0;
+    }
+    /* maybe ftruncate doesn't work if we try to extend the size */
+    err = errno;
+
+#ifndef  HAVE_PWRITE
+    /* we only care about file pointer if we don't use pwrite */
+    if ((off_t)-1 == (curpos = lseek(fd, 0, SEEK_CUR)) ) {
+        errno = err;
+        return -1;
+    }
+#endif
+
+    if ( fstat( fd, &st ) < 0 ) {
+        errno = err;
+        return -1;
+    }
+    
+    if (st.st_size > length) {
+        errno = err;
+        return -1;
+    }
+
+    if (lseek(fd, length -1, SEEK_SET) != length -1) {
+        errno = err;
+        return -1;
+    }
+
+    if (1 != write( fd, &c, 1 )) {
+        /* return the write errno */
+        return -1;
+    }
+
+#ifndef  HAVE_PWRITE
+    if (curpos != lseek(fd, curpos,  SEEK_SET)) {
+        errno = err;
+        return -1;
+    }
+#endif
+
+    return 0;    
+}
+
+/* ------------------------ */
+int ad_rtruncate( struct adouble *ad, const off_t size)
+{
+    if ( sys_ftruncate( ad_reso_fileno(ad),
            size + ad->ad_eid[ ADEID_RFORK ].ade_off ) < 0 ) {
-       return( -1 );
+       return -1;
     }
     ad->ad_rlen = size;    
 
-    return( 0 );
+    return 0;
 }
 
-int ad_dtruncate(ad, size)
-    struct adouble     *ad;
-    const off_t        size;
+int ad_dtruncate(struct adouble *ad, const off_t size)
 {
-    if (ftruncate(ad->ad_df.adf_fd, size) < 0) {
+    if (sys_ftruncate(ad_data_fileno(ad), size) < 0) {
       return -1;
     }
     return 0;