#include "jtraceAPI.h"
#include <stdio.h>
#include "../colors.h"
#include <string.h>


// Sample plugin for JTrace API - for lmkd
// ----------------------------
//
// I made the API very simple but (hopefully) effective - q.v. the H file,
// which I've fully documented.
//
// Basically, you create a dylib, 
//
// Please direct any suggestions for improvements, or additional APIs
// you may want to me via NewAndroidBook.com
// 
//


// These are from lmkd.h
//
enum lmk_cmd {
    LMK_TARGET = 0,         /* Associate minfree with oom_adj_score */
    LMK_PROCPRIO,           /* Register a process and set its oom_adj_score */
    LMK_PROCREMOVE,         /* Unregister a process */
    LMK_PROCPURGE,          /* Purge all registered processes */
    LMK_GETKILLCNT,         /* Get number of kills */
    LMK_SUBSCRIBE,          /* Subscribe for asynchronous events */
    LMK_PROCKILL,           /* Unsolicited msg to subscribed clients on proc kills */
    LMK_UPDATE_PROPS,       /* Reinit properties */
    LMK_STAT_KILL_OCCURRED, /* Unsolicited msg to subscribed clients on proc kills for statsd log */
    LMK_STAT_STATE_CHANGED, /* Unsolicited msg to subscribed clients on state changed */
};

/* LMK_TARGET payload: */
struct lmk_target { 
	int minfree;
	int oom_adj_score;
};

struct lmk_procprio {
	pid_t pid;
	uid_t	uid;
	int oomadj;
};

extern int config_color (void);

int gColor ;

int lmkd_recvmsg  (int Exit, int Pid)
{

	
	char *ob = getOutputBuffer ();
	uint32_t pos =0;
	int readRC = 0;
	if (!Exit)
	{

		long arg0 = getRegValue(REG_ARG_0);
		saveRegValue(REG_ARG_0);

		if (arg0  > 255) { fprintf(stderr,"read %ld?!\n", arg0);}
		pos += sprintf(ob+pos, "%srecvmsg%s (",
				config_color()? BOLD :"", config_color()?NORMAL:"");
		pos += sprintf (ob+pos, "%ld", arg0);
		pos+=sprintf (ob+pos,",");
		updateOutputBufferPos(pos);

		return 0;
	}
	else
	{
	// on exit, print values read. Use jtrace's readProcessMemory
	//
	unsigned long addr =  getRegValue(REG_ARG_1);


	readRC = getRegValue (REG_ARG_RETVAL);

 	char *fdName = getFDName (getSavedRegValue(REG_ARG_0));



	int format = 0;

        if (fdName && strcmp(fdName, "/dev/socket/lmkd") ==0)
	{

		// fd should be /dev/socket/lmkd, since that's the
		// only thing that lmkd read(2)s from..

		// I use alloca because it's simpler and faster
		// caveat: if readRC is too big, it would explode
		// the stack. Either check readRC or use malloc..
		// (but lmkd never reads much..)
		//
		 uint32_t len = getRegValue(2);

		 char *buffer = getIOVecDataFromMsgHdr ((struct msghdr *) getRegValue(1),
                                                       &len, Pid);


		 // pos+=hexDumpToBuffer(ob +pos, 1000, buffer, len, getRegValue(1), 1);

		if (!buffer) {

		pos += sprintf(ob+pos,"<ERROR>");

		}
		else {

		  uint32_t *cmd = (uint32_t *) buffer;
		  // nice trick would be to use union here.
		  //
		  struct lmk_procprio *pp = (struct lmk_procprio *)(cmd + 1);
		if (gColor) { pos+= sprintf(ob+pos,BLUE); }
		 
	       	  uint32_t c = ntohl(*cmd);	

		  switch (c) {
			case LMK_TARGET:
			pos+= sprintf(ob+pos,"LMK_TARGET: \n");

			break;
			case LMK_PROCPRIO:	
			pos+= sprintf(ob+pos,"LMK_PROCPRIO: PID %d (UID %d) set to %d",
			ntohl(pp->pid), ntohl(pp->uid), ntohl(pp->oomadj));

			break;
			case LMK_PROCREMOVE:
			pos+= sprintf (ob+pos,"LMK_PROCREMOVE: PID %d",
			ntohl(pp->pid));
			break;
			default:
			pos += sprintf(ob+pos, "Unhandled command 0x%x\n", c);
		  }

		}



	} 


	else {

		fprintf(stderr,"descriptor not a socket?\n");
	}
	} 
	if (gColor) { pos += sprintf(ob +pos, NORMAL); }
	pos += sprintf(ob+pos, ")= %d", readRC);

	updateOutputBufferPos(pos);


	return 0;
} // lmkd_read 


int init = 0;
__attribute__((constructor)) void _init(void) {
	
	if (init) return;
	init++;	
	fprintf(stderr,"LOADED LMKD PLUGIN\n");
	gColor = config_color();


	int rc= registerSyscallHandler ("recvmsg", // char *SyscallName, // must exist or you'll get -1 
	        lmkd_recvmsg,  // syscall_handler_func Handler,     // Your callback, per above
		0, //              int Bitness,     // 32, 64 or 0 (both)
		0);	//      int Flags);      // as per flags, above


}