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c++linuxshared-memorygoogle-nativeclient

NaCl and shared memory

I have application that write some date in linux shared memory (/dev/shm/datahere). I need to show this data in browser with using google native client. it is real? How I can do this?

Solution

  • I had to dig pretty on the Internet, but I found a solution: Just out of the browser can not access because of the sandbox, but there is a Chrome Apps, which with the help NaCl can access the file system.

    To build Chrome Apps included with NaCl and access to the file system, do the following:

    1. Download nacl_sdk. Update it, to get examples (pepperX)

    2. In a file nacl_sdk/pepper_46/tools/common.mk find a line SANDBOX_ARGS: = --no-sandbox and change to:

    SANDBOX_ARGS: = --no-sandbox --allow-no-sandbox-job --nacl-dangerous-no-sandbox-nonsfinacl

    CHROME_ENV ?=, to:

    CHROME_ENV=NACL_DANGEROUS_ENABLE_FILE_ACCESS=1

    2.1 If you use run_package, then you need write in a file common.mk:

    run_package: check_for_chrome all @echo "$(TOOLCHAIN) $(CONFIG)" > $(CURDIR)/run_package_config Exec=env NACL_DANGEROUS_ENABLE_FILE_ACCESS=1 "$(CHROME_PATH)" --load-and-launch-app=$(CURDIR) $(CHROME_ARGS)

    1. In the Makefile of project need to add this:
    LIBS = ppapi_cpp ppapi pthread nacl_io
DEPS = nacl_io
CFLAGS = -Wall
SOURCES = <filename> .cc

# Build rules generated by macros from common.mk:
$ (foreach dep, $ (DEPS), $ (eval $ (call DEPEND_RULE, $ (dep))))
$ (foreach src, $ (SOURCES), $ (eval $ (call COMPILE_RULE, $ (src), $ (CFLAGS))))

# The PNaCl workflow uses both an unstripped and finalized / stripped binary.
    1. Code example. it is very important - do not read /dev/shm read /var/run/shm:
    int file;
file = open("/var/run/shm/helloworld.txt", O_RDONLY);
char buffer[1024];
memset(&buffer, 0, 1024);
read(file, buffer, 13);
pp::Var var_reply(buffer);
PostMessage(var_reply);

    P.S. Maybe it is not a good solution, but it work for me