Security-59306.120.7.tar.gz

[apple/security.git] / securityd / src / SharedMemoryServer.cpp

diff --git a/securityd/src/SharedMemoryServer.cpp b/securityd/src/SharedMemoryServer.cpp
index 5c437919d8aaf9070354fad04bcbcc6173a153a7..60176b1b7e2d182b36314268adab519dae24b8ef 100644 (file)
--- a/securityd/src/SharedMemoryServer.cpp
+++ b/securityd/src/SharedMemoryServer.cpp
@@ -24,6 +24,7 @@
 #include "SharedMemoryServer.h"
 #include <stdlib.h>
 #include <sys/mman.h>
 #include "SharedMemoryServer.h"
 #include <stdlib.h>
 #include <sys/mman.h>

+#include <sys/errno.h>

 #include <fcntl.h>
 #include <machine/byte_order.h>
 #include <string>
 #include <fcntl.h>
 #include <machine/byte_order.h>
 #include <string>


@@ -31,23 +32,28 @@
 #include <security_utilities/crc.h>
 #include <security_utilities/casts.h>
 #include <unistd.h>
 #include <security_utilities/crc.h>
 #include <security_utilities/casts.h>
 #include <unistd.h>

+#include <vector>

 
 /*
     Logically, these should go in /var/run/mds, but we know that /var/db/mds
     already exists at install time.
 */
 
 
 /*
     Logically, these should go in /var/run/mds, but we know that /var/db/mds
     already exists at install time.
 */
 

-std::string SharedMemoryCommon::SharedMemoryFilePath(const char *segmentName, uid_t uid) {
-    std::string path;
-    uid = SharedMemoryCommon::fixUID(uid);
-    path = SharedMemoryCommon::kMDSMessagesDirectory;   // i.e. /private/var/db/mds/messages/
-    if (uid != 0) {
-        path += std::to_string(uid) + "/";              // e.g. /private/var/db/mds/messages/501/
+static bool makedir(const char *path, mode_t mode) {
+    // Returns true on success. Primarily to centralize logging
+    if (::mkdir(path, mode)==0 || errno==EEXIST) {
+        return true;
+    } else {
+        secdebug("MDSPRIVACY","Failed to make directory: %s (%d)", path, errno);
+        return false;

     }
     }

+}

 
 

-    path += SharedMemoryCommon::kUserPrefix;            // e.g. /var/db/mds/messages/se_
-    path += segmentName;                                // e.g. /var/db/mds/messages/501/se_SecurityMessages
-    return path;
+static void unlinkfile(const char *path) {
+    // Primarily to centralize logging
+    if (::unlink(path)==-1) {
+         secdebug("MDSPRIVACY","Failed to unlink file: %s (%d)", path, errno);
+    }

 }
 
 SharedMemoryServer::SharedMemoryServer (const char* segmentName, SegmentOffsetType segmentSize, uid_t uid, gid_t gid) :
 }
 
 SharedMemoryServer::SharedMemoryServer (const char* segmentName, SegmentOffsetType segmentSize, uid_t uid, gid_t gid) :


@@ -59,42 +65,41 @@ SharedMemoryServer::SharedMemoryServer (const char* segmentName, SegmentOffsetTy
 
     // make the mds directory, just in case it doesn't exist
     if (mUID == 0) {
 
     // make the mds directory, just in case it doesn't exist
     if (mUID == 0) {

-        mkdir(SharedMemoryCommon::kMDSDirectory, perm1777);
-        mkdir(SharedMemoryCommon::kMDSMessagesDirectory, perm0755);
+        makedir(SharedMemoryCommon::kMDSDirectory, perm1777);
+        makedir(SharedMemoryCommon::kMDSMessagesDirectory, perm0755);

     } else {
         // Assume kMDSMessagesDirectory was created first by securityd
         std::string uidstr = std::to_string(mUID);
         std::string upath = SharedMemoryCommon::kMDSMessagesDirectory;
         upath += "/" + uidstr;
     } else {
         // Assume kMDSMessagesDirectory was created first by securityd
         std::string uidstr = std::to_string(mUID);
         std::string upath = SharedMemoryCommon::kMDSMessagesDirectory;
         upath += "/" + uidstr;

-        mkdir(upath.c_str(), perm0755);
+        makedir(upath.c_str(), perm0755);

     }
     mFileName = SharedMemoryCommon::SharedMemoryFilePath(segmentName, uid);
 
     // make the file name
     // clean any old file away
     }
     mFileName = SharedMemoryCommon::SharedMemoryFilePath(segmentName, uid);
 
     // make the file name
     // clean any old file away

-    unlink(mFileName.c_str());
+    unlinkfile(mFileName.c_str());

 
     // open the file
     secdebug("MDSPRIVACY","creating %s",mFileName.c_str ());
 
     // open the file
     secdebug("MDSPRIVACY","creating %s",mFileName.c_str ());

-    mBackingFile = open (mFileName.c_str (), O_RDWR | O_CREAT, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
+    if(mUID != 0) {
+        mBackingFile = open (mFileName.c_str (), O_RDWR | O_CREAT | O_EXCL, perm0600);
+    }
+    else {
+        mBackingFile = open (mFileName.c_str (), O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
+    }
+

     if (mBackingFile < 0)
     {
         secdebug("MDSPRIVACY","creation of %s failed", mFileName.c_str());
         return;
     }
 
     if (mBackingFile < 0)
     {
         secdebug("MDSPRIVACY","creation of %s failed", mFileName.c_str());
         return;
     }
 

-    int rx = chown(mFileName.c_str (), uid, gid);
+    int rx = fchown(mBackingFile, uid, gid);

     if (rx) {
         secdebug("MDSPRIVACY","chown of %s to %d/%d failed : %d", mFileName.c_str(), uid, gid, rx);
     }
 
     if (rx) {
         secdebug("MDSPRIVACY","chown of %s to %d/%d failed : %d", mFileName.c_str(), uid, gid, rx);
     }
 

-    if (mUID != 0) {
-        int rx = fchmod(mBackingFile, perm0600);
-        if (rx) {
-            secdebug("MDSPRIVACY","chmod of %s to %x failed : %d", mFileName.c_str(), perm0600, rx);
-        }
-    }
-

     // set the segment size
     ftruncate (mBackingFile, segmentSize);
     
     // set the segment size
     ftruncate (mBackingFile, segmentSize);
     


@@ -104,7 +109,7 @@ SharedMemoryServer::SharedMemoryServer (const char* segmentName, SegmentOffsetTy
     if (mSegment == MAP_FAILED) // can't map the memory?
     {
         mSegment = NULL;
     if (mSegment == MAP_FAILED) // can't map the memory?
     {
         mSegment = NULL;

-        unlink(mFileName.c_str());
+        unlinkfile(mFileName.c_str());

     } else {
         mDataPtr = mDataArea = mSegment + sizeof(SegmentOffsetType);
         mDataMax = mSegment + segmentSize;;
     } else {
         mDataPtr = mDataArea = mSegment + sizeof(SegmentOffsetType);
         mDataMax = mSegment + segmentSize;;


@@ -127,7 +132,7 @@ SharedMemoryServer::~SharedMemoryServer ()
     close(mBackingFile);
        
        // mark the segment for deletion
     close(mBackingFile);
        
        // mark the segment for deletion

-       unlink (mFileName.c_str ());
+       unlinkfile(mFileName.c_str ());

 }
 
 
 }
 
 


@@ -141,18 +146,21 @@ const SegmentOffsetType
 
 void SharedMemoryServer::WriteMessage (SegmentOffsetType domain, SegmentOffsetType event, const void *message, SegmentOffsetType messageLength)
 {
 
 void SharedMemoryServer::WriteMessage (SegmentOffsetType domain, SegmentOffsetType event, const void *message, SegmentOffsetType messageLength)
 {

-    // backing file MUST be right size
-    ftruncate (mBackingFile, mSegmentSize);
+    // backing file MUST be right size, don't ftruncate() more then needed though to avoid reaching too deep into filesystem
+    struct stat sb;
+    if (::fstat(mBackingFile, &sb) == 0 && sb.st_size != (off_t)mSegmentSize) {
+        ::ftruncate(mBackingFile, mSegmentSize);
+    }

 
        // assemble the final message
        ssize_t messageSize = kHeaderLength + messageLength;
 
        // assemble the final message
        ssize_t messageSize = kHeaderLength + messageLength;

-       u_int8_t finalMessage[messageSize];
-       SegmentOffsetType *fm  = (SegmentOffsetType*) finalMessage;
+       std::vector<u_int8_t> finalMessage(messageSize);
+       SegmentOffsetType *fm  = (SegmentOffsetType*) finalMessage.data();

        fm[0] = OSSwapHostToBigInt32(domain);
        fm[1] = OSSwapHostToBigInt32(event);
        memcpy(&fm[2], message, messageLength);
        
        fm[0] = OSSwapHostToBigInt32(domain);
        fm[1] = OSSwapHostToBigInt32(event);
        memcpy(&fm[2], message, messageLength);
        

-       SegmentOffsetType crc = CalculateCRC(finalMessage, messageSize);
+       SegmentOffsetType crc = CalculateCRC(finalMessage.data(), messageSize);

        
        // write the length
        WriteOffset(int_cast<size_t, SegmentOffsetType>(messageSize));
        
        // write the length
        WriteOffset(int_cast<size_t, SegmentOffsetType>(messageSize));


@@ -161,7 +169,7 @@ void SharedMemoryServer::WriteMessage (SegmentOffsetType domain, SegmentOffsetTy
        WriteOffset(crc);
        
        // write the data
        WriteOffset(crc);
        
        // write the data

-       WriteData (finalMessage, int_cast<size_t, SegmentOffsetType>(messageSize));
+       WriteData (finalMessage.data(), int_cast<size_t, SegmentOffsetType>(messageSize));

        
        // write the data count
        SetProducerOffset(int_cast<size_t, SegmentOffsetType>(mDataPtr - mDataArea));
        
        // write the data count
        SetProducerOffset(int_cast<size_t, SegmentOffsetType>(mDataPtr - mDataArea));