Implement sendfile syscall

Author: dark-lbp

qiling/os/posix/syscall/sendfile.py

@@ -6,11 +6,33 @@
 from qiling import Qiling
 from qiling.os.posix.const import NR_OPEN
 
-def ql_syscall_sendfile64(ql: Qiling, out_fd: int, in_fd: int, offest: int, count: int):
-    if (0 <= out_fd < NR_OPEN and ql.os.fd[out_fd] != 0) and (0 <= in_fd < NR_OPEN and ql.os.fd[in_fd] != 0):
-        ql.os.fd[in_fd].lseek(ql.unpack32(ql.mem.read(offest, 4)))
+
+def ql_syscall_sendfile64(ql: Qiling, out_fd: int, in_fd: int, offset: int, count: int):
+    # https://linux.die.net/man/2/sendfile64
+    return ql_syscall_sendfile(ql, out_fd, in_fd, offset, count)
+
+
+def ql_syscall_sendfile(ql: Qiling, out_fd: int, in_fd: int, offset: int, count: int):
+    # https://man7.org/linux/man-pages/man2/sendfile.2.html
+    if 0 <= out_fd < NR_OPEN and 0 <= in_fd < NR_OPEN \
+            and ql.os.fd[out_fd] != 0 and ql.os.fd[in_fd] != 0:
+
+        in_fd_pos = ql.os.fd[in_fd].tell()
+        if offset:
+            # Handle sendfile64 and sendfile offset_ptr
+            offset = ql.unpack(ql.mem.read(offset, ql.pointersize))
+        else:
+            offset = in_fd_pos
+
+        ql.os.fd[in_fd].lseek(offset)
         buf = ql.os.fd[in_fd].read(count)
+        if offset:
+            current_offset = ql.os.fd[in_fd].tell()
+            ql.mem.write(offset, ql.pack(current_offset))
+            ql.os.fd[in_fd].lseek(in_fd_pos)
+
         regreturn = ql.os.fd[out_fd].write(buf)
+
     else:
         regreturn = -1