libssh2:如何通过libssh2_channel_write发送数据

时间:2014-04-11 23:26:14

标签: passwords libssh2

编辑: 这是完整的代码。修改了代码以使用路由器,但用例是相同的。一旦我使用libssh2_channel_write()发出密码,后续的libssh2_channel_read()将失败并显示LIBSSH2_ERROR_SOCKET_RECV。不知道为什么。我无法将后续命令发送到远程设备并获取其输出。

逻辑是在远程设备上执行命令(libssh2_channel_exec)。此命令执行将抛出客户端输入的密码。现在通过libssh2_channel_read()读取流并确保要求输入密码,并通过libssh2_channel_write()将密码写入通道。通过后续读取[这是LIB与ERROR_SOCKET_RECV失败的位置]确保远程设备上的密码被接受,然后通过libssh2_channel_write()发送要执行的命令并读取命令输出。我错过了什么吗?

    for( ;; )
    {
        /* loop until we block */ 
        int rc;
        do
        {
            char buffer[0x4000];
            rc = libssh2_channel_read( channel, buffer, sizeof(buffer) );

            if( rc > 0 )
            {
                int i;
                char *enable = "check-password\n";
                int ret;
                bytecount += rc;
                fprintf(stderr, "We read [%d] bytes:\n", bytecount);
                fputc('[', stderr);
                for( i=0; i < rc; ++i )
                    fputc( buffer[i], stderr);
                fputc(']', stderr);


                if ( strstr(buffer, "Password:") != NULL ){
                    fprintf(stderr, "Sending the password now\n");
                    while((ret = libssh2_channel_write(channel, enable, strlen(enable))) == LIBSSH2_ERROR_EAGAIN) {
                        printf("ERROR_EAGAIN - sending password again\n");
                    }

                    fprintf(stderr, "Wrote [%d] bytes: \n", ret);
                    flag = 1;
                    continue;
                }
                if (!flag){ // start
                    char *cmd = "show clock\n";
                    int ret;
                    fprintf(stderr, "THIS Fetching show clock command now\n");
                    while((ret = libssh2_channel_write(channel, cmd, strlen(cmd))) == LIBSSH2_ERROR_EAGAIN) {
                        printf("ERROR_EAGAIN - sending show clock again\n");
                    }
                    flag = 1;
                } // end
            }
            else {
                if(rc != LIBSSH2_ERROR_EAGAIN)
                    fprintf(stderr, "libssh2_channel_read returned [%d]:\n ", rc);
            }
        }
        while( rc > 0 );

        /* this is due to blocking that would occur otherwise so we loop on
           this condition */ 
        if( rc == LIBSSH2_ERROR_EAGAIN )
        {
            int check;
            check = waitsocket(sock, session);
        }
        else
            break;
    }

1 个答案:

答案 0 :(得分:0)

为了遵守规则,我创建了一个包含我的问题的新线程。应该删除这个答案。

感谢。

泽埃夫