From: Sungbae Yoo <sungbae.yoo@samsung.com>
Date: Tue, 19 Apr 2016 10:05:10 +0000 (+0900)
Subject: Add support for filesystem mount
X-Git-Tag: accepted/tizen/common/20160427.144522~2^2~1
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=b372e25744f64e94bfff053f6e0d84898c8f570c;p=platform%2Fcore%2Fsecurity%2Fdevice-policy-manager.git

Add support for filesystem mount

Change-Id: Ie5b0d9bd48f7e394903142450b72a3b28623ec51
Signed-off-by: Sungbae Yoo <sungbae.yoo@samsung.com>
---

diff --git a/common/filesystem.cpp b/common/filesystem.cpp
index de56ef5..d27ed50 100644
--- a/common/filesystem.cpp
+++ b/common/filesystem.cpp
@@ -15,6 +15,7 @@
  */
 
 #include <sys/types.h>
+#include <sys/mount.h>
 #include <sys/stat.h>
 #include <unistd.h>
 #include <fcntl.h>
@@ -22,6 +23,7 @@
 #include <string.h>
 
 #include <string>
+#include <sstream>
 
 #include "filesystem.h"
 #include "error.h"
@@ -395,4 +397,96 @@ DirectoryIterator& DirectoryIterator::operator++()
     return *this;
 }
 
+static const struct mountOption {
+    const char* name;
+    int clear;
+    int flag;
+} mountOptions[] = {
+    { "defaults",      0, 0                },
+    { "ro",            0, MS_RDONLY        },
+    { "rw",            1, MS_RDONLY        },
+    { "suid",          1, MS_NOSUID        },
+    { "nosuid",        0, MS_NOSUID        },
+    { "dev",           1, MS_NODEV         },
+    { "nodev",         0, MS_NODEV         },
+    { "exec",          1, MS_NOEXEC        },
+    { "noexec",        0, MS_NOEXEC        },
+    { "sync",          0, MS_SYNCHRONOUS   },
+    { "async",         1, MS_SYNCHRONOUS   },
+    { "dirsync",       0, MS_DIRSYNC       },
+    { "remount",       0, MS_REMOUNT       },
+    { "mand",          0, MS_MANDLOCK      },
+    { "nomand",        1, MS_MANDLOCK      },
+    { "atime",         1, MS_NOATIME       },
+    { "noatime",       0, MS_NOATIME       },
+    { "diratime",      1, MS_NODIRATIME    },
+    { "nodiratime",    0, MS_NODIRATIME    },
+    { "bind",          0, MS_BIND          },
+    { "rbind",         0, MS_BIND | MS_REC },
+    { "relatime",      0, MS_RELATIME      },
+    { "norelatime",    1, MS_RELATIME      },
+    { "strictatime",   0, MS_STRICTATIME   },
+    { "nostrictatime", 1, MS_STRICTATIME   },
+    { NULL,            0, 0                },
+};
+
+static unsigned long parseMountOptions(const std::string& opts, std::string& mntdata)
+{
+    std::stringstream optsSstream(opts);
+    const struct mountOption* mo;
+    unsigned long mntflags = 0L;
+    std::string opt;
+
+    while (std::getline(optsSstream, opt, ',')) {
+        for (mo = mountOptions; mo->name != NULL; mo++) {
+            if (opt == mo->name) {
+                if (mo->clear) {
+                    mntflags &= ~mo->flag;
+                } else {
+                    mntflags |= mo->flag;
+                }
+                break;
+            }
+            if (mo->name != NULL) {
+                continue;
+            }
+            if (!mntdata.empty()) {
+                mntdata += ",";
+            }
+            mntdata += opt;
+        }
+    }
+
+    return mntflags;
+}
+
+void Mount::mountEntry(const std::string& src, const std::string& dest, const std::string& type, const std::string& opts)
+{
+    int ret;
+    unsigned long mntflags;
+    std::string mntdata;
+
+    mntflags = parseMountOptions(opts, mntdata);
+
+    ret = ::mount(src.c_str(),
+                  dest.c_str(),
+                  type.c_str(),
+                  mntflags & ~MS_REMOUNT,
+                  mntdata.c_str());
+
+    if (ret) {
+        if ((mntflags & MS_REMOUNT) || (mntflags & MS_BIND)) {
+            ret = ::mount(src.c_str(),
+                          dest.c_str(),
+                          type.c_str(),
+                          mntflags | MS_REMOUNT,
+                          mntdata.c_str());
+        }
+
+        if (ret) {
+            throw runtime::Exception("failed to mount " + src + " on " + dest);
+        }
+    }
+}
+
 } // namespace runtime
diff --git a/common/filesystem.h b/common/filesystem.h
index 2d16ba2..6383824 100644
--- a/common/filesystem.h
+++ b/common/filesystem.h
@@ -196,6 +196,14 @@ private:
     std::string basename;
 };
 
+class Mount final {
+public:
+    Mount() = delete;
+
+    static void mountEntry(const std::string& src, const std::string& dest,
+                           const std::string& type, const std::string& opts);
+};
+
 int Open(const std::string& path, int flags, mode_t mode);
 void Close(int fd);