The s2eget tool allows to easily upload files from the host into the guest in S2E mode. The typical use case for this tool is to set up a VM snapshot that, when resumed in S2E mode, automatically downloads a program from the host and starts symbolically executing it.
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To use s2eget, enable the HostFiles plugin in the S2E configuration file. This file is called config.lua and can be placed anywhere you wish; its location will be passed via a command line argument. For example, here is a simple config.lua:
plugins = {
"HostFiles"
}
pluginsConfig = {}
pluginsConfig.HostFiles = {
baseDirs = {"/path/to/host/dir1", "/path/to/host/dir2"}
}
The pluginsConfig.HostFiles.baseDirs configuration option specifies what directories on the host should be exported to the guest. The paths can be either absolute, relative, or empty in which case the s2e output directory will be exported.
First, boot the VM in the S2E version of QEMU in non-S2E mode:
$ $S2EDIR/build/qemu-release/i386-softmmu/qemu-system-i386 s2e_disk.raw.s2e -m 1024
Copy s2eget into the guest over SSH (or any other method). Then run the tool, for example, as follows:
guest$ ./s2eget <filename> && chmod +x ./<filename> && ./<filename>
where <filename> specifies what file to download from the host and execute in the guest.
When being run like that in non-S2E mode, s2eget simply waits. At that point, save the VM snapshot and then load it in S2E mode. s2eget will detect it and download the file. The rest of the command line will make it executable and execute it.
Note that you could resume this snapshot as many times as you want, changing the program and/or trying different S2E options.