rsudo/rsudo.c

/*
  rsudo - request sudo

  this file and distributions are
  memework property.

  unauthorized distribution of this file
  and related files (like header files)
  is strictly prohibited by people other than the owner.

  Copyright (C) Luna Mendes 2017
*/

#include <stdlib.h>
#include <stdio.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <string.h>
#include <unistd.h>

#include "log.h"

const char* sock_path = "/home/luna/local.git/memed/memed.succ";

struct header_s {
    unsigned int len;
    int op;
};

char *join(const char* s1, const char* s2)
{
    char* result = malloc(strlen(s1) + strlen(s2) + 1);

    if (result)
    {
        strcpy(result, s1);
        strcat(result, s2);
    }

    return result;
}

int main(int argc, char **argv)
{
    // the idea here is to open the socket
    // send a message to it and run asap
    struct sockaddr_un addr;

    // receiving data from socket
    struct header_s header;
    char buffer[1024];

    // fd file descriptor
    // rc read count
    int fd, rc;

    if ( (fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1)
    {
        perror("socket error");
        exit(-1);
    }

    memset(&addr, 0, sizeof(addr));
    addr.sun_family = AF_UNIX;

    strncpy(addr.sun_path, sock_path, sizeof(addr.sun_path)-1);

    LOG_INFO("main", "connecting");
    if ( connect(fd, (struct sockaddr*)&addr, sizeof(addr)) == -1 )
    {
        perror("connect error");
        exit(-1);
    }

    // read the hello
    // We start by reading and filling our header
    if ((rc = recv(fd, &header, 8, 0)) < 0)
    {
        perror("recv");
        exit(-1);
    }

    printf("%d %d\n", header.len, header.op);

    // Then we proceed to, with the data from header,
    // read the message
    if ((rc = recv(fd, &buffer, header.len, 0)) < 0)
    {
        perror("recv");
        exit(-1);
    }


    if(strlen(buffer) - 1 != header.len)
    {
        printf("%u %d\n", strlen(buffer), header.len);
        LOG_ERROR("main", "hello length != header length");
        exit(-1);
    }

    if(header.op != 0)
    {
        LOG_ERROR("main", "incorrect header op");
        exit(-1);
    }

    LOG_INFO("main", "finished hello");

    char *tot = "";
    for(int i = 1; i < argc; i++)
    {
        char *arg = argv[i];
        tot = join(tot, arg);

        if(i != argc - 1) tot = join(tot, " ");
    }

    // convert uid to string
    int uid = getuid();
    char uid_str[6];

    sprintf(uid_str, "%d", uid);
    
    tot = join(tot, ",");
    tot = join(tot, uid_str);

    printf("sending command: %s\n", tot);

    // encode our data
    struct header_s send_h;
    send_h.len = strlen(tot);
    send_h.op = 2;
    
    if (send(fd, &send_h, sizeof(send_h), 0) < 0)
    {
        perror("send req");
        exit(-1);
    }
    
    if (send(fd, tot, strlen(tot), 0) < 0)
    {
        perror("send req total");
        exit(-1);
    }

    shutdown(fd, SHUT_RDWR);

    printf("Successfully communicated your command to memed!\n");

    close(fd);
    exit(0);
}