From: Frank Lahm <franklahm@googlemail.com>
Date: Thu, 7 Mar 2013 18:03:30 +0000 (+0100)
Subject: Fix an issue caused by read-only ._ ressource forks
X-Git-Url: https://arthur.barton.de/gitweb/?p=netatalk.git;a=commitdiff_plain;h=fa873cb4f32758ea6f5e3492d9e4828cfcbacdea

Fix an issue caused by read-only ._ ressource forks

Fixes bug #502.
---

diff --git a/NEWS b/NEWS
index 7f43cf0f..8a628754 100644
--- a/NEWS
+++ b/NEWS
@@ -24,6 +24,8 @@ Changes in 3.0.3
 * NEW: dtrace probes, cf include/atalk/afp_dtrace.d for available
        probes.
 * UPD: Reload groups when reloading volumes. FR #71.
+* FIX: Attempt to read read-only ._ rfork results in disconnect.
+       Fixes bugs #502.
 
 Changes in 3.0.2
 ================
diff --git a/etc/afpd/fork.c b/etc/afpd/fork.c
index 776d2f63..7f5487ee 100644
--- a/etc/afpd/fork.c
+++ b/etc/afpd/fork.c
@@ -328,8 +328,6 @@ int afp_openfork(AFPObj *obj _U_, char *ibuf, size_t ibuflen _U_, char *rbuf, si
     } else {
         eid = ADEID_RFORK;
         adflags |= ADFLAGS_RF;
-        if (!(access & OPENACC_WR))
-            adflags |= ADFLAGS_NORF;
     }
 
     if (access & OPENACC_WR) {
diff --git a/libatalk/adouble/ad_open.c b/libatalk/adouble/ad_open.c
index 3cedebab..ef971bb9 100644
--- a/libatalk/adouble/ad_open.c
+++ b/libatalk/adouble/ad_open.c
@@ -766,7 +766,8 @@ static int ad_header_upgrade_ea(struct adouble *ad _U_, const char *name _U_)
  *
  * We're called because opening ADFLAGS_HF caused an error.
  * 1. In case ad_open is called with ADFLAGS_NOHF the error is suppressed.
- * 2. If ad_open was called with ADFLAGS_DF we may have opened the datafork and thus
+ * 2. Open non-existent ressource fork, this will just result in first read return EOF
+ * 3. If ad_open was called with ADFLAGS_DF we may have opened the datafork and thus
  *    ought to close it before returning with an error condition.
  */
 static int ad_error(struct adouble *ad, int adflags)
@@ -775,7 +776,9 @@ static int ad_error(struct adouble *ad, int adflags)
     if (adflags & ADFLAGS_NOHF) { /* 1 */
         return 0;
     }
-    if (adflags & (ADFLAGS_DF | ADFLAGS_SETSHRMD | ADFLAGS_CHECK_OF)) { /* 2 */
+    if ((adflags & ADFLAGS_RDONLY) && (adflags & ADFLAGS_RF) && (errno == ENOENT)) /* 2 */
+        return 0;
+    if (adflags & (ADFLAGS_DF | ADFLAGS_SETSHRMD | ADFLAGS_CHECK_OF)) { /* 3 */
         ad_close( ad, ADFLAGS_DF );
         err = errno;
     }
@@ -1203,7 +1206,7 @@ static int ad_open_rf_v2(const char *path, int adflags, int mode, struct adouble
 
     LOG(log_debug, logtype_ad, "ad_open_rf_v2(\"%s\"): BEGIN", fullpathname(path));
 
-    if (!AD_META_OPEN(ad) && !(adflags & ADFLAGS_NORF))
+    if (!AD_META_OPEN(ad) && !(adflags & (ADFLAGS_NORF | ADFLAGS_RDONLY)))
         EC_FAIL;
     if (AD_META_OPEN(ad))
         ad->ad_reso_refcount++;
@@ -1256,12 +1259,34 @@ static int ad_open_rf_ea(const char *path, int adflags, int mode, struct adouble
 #else
     EC_NULL_LOG( rfpath = ad->ad_ops->ad_path(path, adflags) );
     if ((ad_reso_fileno(ad) = open(rfpath, oflags)) == -1) {
-        if (!(adflags & ADFLAGS_CREATE))
-            EC_FAIL;
-        oflags |= O_CREAT;
-        EC_NEG1_LOG( ad_reso_fileno(ad) = open(rfpath, oflags, mode) );
-        LOG(log_debug, logtype_ad, "ad_open_rf(\"%s\"): created adouble rfork: \"%s\"",
-            path, rfpath);
+        if (!(adflags & ADFLAGS_CREATE)) {
+            switch (errno) {
+            case EACCES:
+            case EPERM:
+            case EROFS:
+                if (!(adflags & ADFLAGS_RDONLY)) {
+                    LOG(log_error, logtype_ad, "ad_open_rf_ea(\"%s\"): \"%s\"", fullpathname(rfpath), strerror(errno));
+                    EC_FAIL;
+                }
+                oflags &= ~O_RDWR;
+                oflags |= O_RDONLY;
+                if ((ad_reso_fileno(ad) = open(rfpath, oflags)) == -1) {
+                    LOG(log_error, logtype_ad, "ad_open_rf_ea(\"%s\"): \"%s\"", fullpathname(rfpath), strerror(errno));
+                    EC_FAIL;
+                }
+                break;
+            case ENOENT:
+                EC_EXIT_STATUS(0);
+            default:
+                LOG(log_error, logtype_ad, "ad_open_rf_ea(\"%s\"): \"%s\"", fullpathname(rfpath), strerror(errno));
+                EC_FAIL;
+            }
+        } else {
+            oflags |= O_CREAT;
+            EC_NEG1_LOG( ad_reso_fileno(ad) = open(rfpath, oflags, mode) );
+            LOG(log_debug, logtype_ad, "ad_open_rf(\"%s\"): created adouble rfork: \"%s\"",
+                path, rfpath);
+        }
     }
 #endif
     opened = 1;