static void read_packet()

in sdk/userspace/fpga_mgmt_tools/src/virtual_jtag_server.c [138:280]

• 104 lines of code
• 27 McCabe index (conditional complexity)

static void read_packet(XvcClient * c) {
    unsigned char * cbuf;
    unsigned char * cend;
    unsigned fill;

    reply_buf_size(max_packet_len);


    struct timeval stop, start;

read_more:

    cbuf = c->buf;
    cend = cbuf + c->buf_len;
    fill = 0;
    reply_len = 0;
    for (;;) {
        unsigned char * p = cbuf;
        unsigned char * e = p + 30 < cend ? p + 30 : cend;
        int len;

        while (p < e && *p != ':') {
            // printf("cycle: %d at %x ", *p, p);
            p++;
        }
        if (p >= e) {
            if (p - cbuf >= 30) {
                fprintf(stderr, "protocol error: received %.30s\n", cbuf);
                goto error;
            }
            fill = 1;
            break;
        }
        p++;
        len = p - cbuf;

        if (len == 8 && memcmp(cbuf, "getinfo:", len) == 0) {
            snprintf((char *)reply_buf + reply_len, 100, "xvcServer_v%u.%u:%u\n",
                     XVC_VERSION / 10, XVC_VERSION % 10, c->buf_max);
            reply_len += strlen((char *)reply_buf + reply_len);
            goto reply;
        }



        if (len == 6 && memcmp(cbuf, "shift:", len) == 0) {

            gettimeofday(&start, NULL);

            unsigned bits;
            unsigned bytes;

            if (cend < p + 4) {
                fill = 1;
                break;
            }
            bits = get_uint_le(p, 4);
            bytes = (bits + 7) / 8;
            if (cend < p + 4 + bytes * 2) {
                assert(p + 4 + bytes * 2 - cbuf <= c->buf_max);
                fill = 1;
                break;
            }
            p += 4;

            if (!c->pending_error[0]) {
                // fprintf(stdout, "bits received %d %d %x %x\n", bits, bytes, p[0], p[bytes]);
        
                shift_tms_tdi(c->jtag_pci_bar, bits, p, p + bytes, reply_buf + reply_len);
            }
            if (c->pending_error[0]) {
                printf("Problem\n");
                memset(reply_buf + reply_len, 0, bytes);
            }
            reply_len += bytes;
            p += bytes * 2;

            gettimeofday(&stop, NULL);
            //printf("Shift external %lu u-seconds\n", stop.tv_usec - start.tv_usec);

            goto reply_with_optional_status;
        }

        if (len == 7 && memcmp(cbuf, "settck:", len) == 0) {
            unsigned long nsperiod;
            unsigned long resnsperiod;

            if (cend < p + 4) {
                fill = 1;
                break;
            }
            nsperiod = get_uint_le(p, 4);
            p += 4;

            if (!c->pending_error[0])
                set_tck(nsperiod, &resnsperiod);
            if (c->pending_error[0])
                resnsperiod = nsperiod;

            set_uint_le(reply_buf + reply_len, 4, resnsperiod);
            reply_len += 4;
            goto reply_with_optional_status;
        }



        // fprintf(stderr, "protocol error: received len %d", (int)len);
        fprintf(stderr, "protocol error: received %.*s\n", (int)len, cbuf);
        goto error;

    reply_with_optional_status:
        // printf("Here2\n");
        if (!c->enable_status) goto reply;

    reply:
        cbuf = p;
    }

    if (c->buf < cbuf) {

        if (send_packet(c, reply_buf, reply_len) < 0) goto error;
        consume_packet(c, cbuf - c->buf);
        
        gettimeofday(&stop, NULL);
        // if (start.tv_usec != 0)
        //     printf("Shift send packet %lu u-seconds\n", stop.tv_usec - start.tv_usec);
        
        if (c->buf_len && !fill) goto read_more;
    }

    {
        int len = recv(c->fd, c->buf + c->buf_len, c->buf_max - c->buf_len, 0);
        if (len > 0) {
            c->buf_len += len;
            goto read_more;
        }
        if (len < 0) goto error;
    }
    return;

error:
    fprintf(stderr, "XVC connection terminated: error %d\n", errno);
}