Subversion Repositories planix.SVN

/* posix */
#include <sys/types.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <signal.h>

/* socket extensions */
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/un.h>
#include <netdb.h>

#include "priv.h"

static char pbotch[] = "rcmd: protocol botch\n";
static char lbotch[] = "rcmd: botch starting error stream\n";

static void
ding(int)
{
}

int
rcmd(char **dst, int port, char *luser, char *ruser, char *cmd, int *fd2p)
{
        char c;
        int i, fd, lfd, fd2, port2;
        struct hostent *h;
        Rock *r;
        struct sockaddr_in in;
        char buf[128];
        void    (*x)(int);

        h = gethostbyname(*dst);
        if(h == 0)
                return -1;
        *dst = h->h_name;

        /* connect using a reserved tcp port */
        fd = socket(PF_INET, SOCK_STREAM, 0);
        if(fd < 0)
                return -1;
        r = _sock_findrock(fd, 0);
        if(r == 0){
                errno = ENOTSOCK;
                return -1;
        }
        r->reserved = 1;
        in.sin_family = AF_INET;
        in.sin_port = htons(port);
        memmove(&in.sin_addr, h->h_addr_list[0], sizeof(in.sin_addr));
        if(connect(fd, &in, sizeof(in)) < 0){
                close(fd);
                return -1;
        }

        /* error stream */
        lfd = -1;
        if(fd2p){
                /* create an error stream and wait for a call in */
                for(i = 0; i < 10; i++){
                        lfd = rresvport(&port2);
                        if(lfd < 0)
                                continue;
                        if(listen(lfd, 1) == 0)
                                break;
                        close(lfd);
                }
                if(i >= 10){
                        fprintf(stderr, pbotch);
                        return -1;
                }

                snprintf(buf, sizeof buf, "%d", port2);
                if(write(fd, buf, strlen(buf)+1) < 0){
                        close(fd);
                        close(lfd);
                        fprintf(stderr, lbotch);
                        return -1;
                }
        } else {
                if(write(fd, "", 1) < 0){
                        fprintf(stderr, pbotch);
                        return -1;
                }
        }

        /* pass id's and command */
        if(write(fd, luser, strlen(luser)+1) < 0
        || write(fd, ruser, strlen(ruser)+1) < 0
        || write(fd, cmd, strlen(cmd)+1) < 0){
                fprintf(stderr, pbotch);
                return -1;
        }

        fd2 = -1;
        if(fd2p){
                x = signal(SIGALRM, ding);
                alarm(15);
                fd2 = accept(lfd, &in, &i);
                alarm(0);
                close(lfd);
                signal(SIGALRM, x);

                if(fd2 < 0){
                        close(fd);
                        close(lfd);
                        fprintf(stderr, lbotch);
                        return -1;
                }
                *fd2p = fd2;
        }

        /* get reply */
        if(read(fd, &c, 1) != 1){
                if(fd2p){
                        close(fd2);
                        *fd2p = -1;
                }
                fprintf(stderr, pbotch);
                return -1;
        }
        if(c == 0)
                return fd;
        i = 0;
        while(c){
                buf[i++] = c;
                if(read(fd, &c, 1) != 1)
                        break;
                if(i >= sizeof(buf)-1)
                        break;
        }
        buf[i] = 0;
        fprintf(stderr, "rcmd: %s\n", buf);
        close(fd);
        return -1;
}