static int ccp_printpkt()

in net/ip/lwip_base/src/netif/ppp/ccp.c [1522:1644]

• 114 lines of code
• 33 McCabe index (conditional complexity)

static int ccp_printpkt(const u_char *p, int plen, void (*printer) (void *, const char *, ...), void *arg) {
    const u_char *p0, *optend;
    int code, id, len;
    int optlen;

    p0 = p;
    if (plen < HEADERLEN)
	return 0;
    code = p[0];
    id = p[1];
    len = (p[2] << 8) + p[3];
    if (len < HEADERLEN || len > plen)
	return 0;

    if (code >= 1 && code <= (int)LWIP_ARRAYSIZE(ccp_codenames) && ccp_codenames[code-1] != NULL)
	printer(arg, " %s", ccp_codenames[code-1]);
    else
	printer(arg, " code=0x%x", code);
    printer(arg, " id=0x%x", id);
    len -= HEADERLEN;
    p += HEADERLEN;

    switch (code) {
    case CONFREQ:
    case CONFACK:
    case CONFNAK:
    case CONFREJ:
	/* print list of possible compression methods */
	while (len >= 2) {
	    code = p[0];
	    optlen = p[1];
	    if (optlen < 2 || optlen > len)
		break;
	    printer(arg, " <");
	    len -= optlen;
	    optend = p + optlen;
	    switch (code) {
#if MPPE_SUPPORT
	    case CI_MPPE:
		if (optlen >= CILEN_MPPE) {
		    u_char mppe_opts;

		    MPPE_CI_TO_OPTS(&p[2], mppe_opts);
		    printer(arg, "mppe %s %s %s %s %s %s%s",
			    (p[2] & MPPE_H_BIT)? "+H": "-H",
			    (p[5] & MPPE_M_BIT)? "+M": "-M",
			    (p[5] & MPPE_S_BIT)? "+S": "-S",
			    (p[5] & MPPE_L_BIT)? "+L": "-L",
			    (p[5] & MPPE_D_BIT)? "+D": "-D",
			    (p[5] & MPPE_C_BIT)? "+C": "-C",
			    (mppe_opts & MPPE_OPT_UNKNOWN)? " +U": "");
		    if (mppe_opts & MPPE_OPT_UNKNOWN)
			printer(arg, " (%.2x %.2x %.2x %.2x)",
				p[2], p[3], p[4], p[5]);
		    p += CILEN_MPPE;
		}
		break;
#endif /* MPPE_SUPPORT */
#if DEFLATE_SUPPORT
	    case CI_DEFLATE:
	    case CI_DEFLATE_DRAFT:
		if (optlen >= CILEN_DEFLATE) {
		    printer(arg, "deflate%s %d",
			    (code == CI_DEFLATE_DRAFT? "(old#)": ""),
			    DEFLATE_SIZE(p[2]));
		    if (DEFLATE_METHOD(p[2]) != DEFLATE_METHOD_VAL)
			printer(arg, " method %d", DEFLATE_METHOD(p[2]));
		    if (p[3] != DEFLATE_CHK_SEQUENCE)
			printer(arg, " check %d", p[3]);
		    p += CILEN_DEFLATE;
		}
		break;
#endif /* DEFLATE_SUPPORT */
#if BSDCOMPRESS_SUPPORT
	    case CI_BSD_COMPRESS:
		if (optlen >= CILEN_BSD_COMPRESS) {
		    printer(arg, "bsd v%d %d", BSD_VERSION(p[2]),
			    BSD_NBITS(p[2]));
		    p += CILEN_BSD_COMPRESS;
		}
		break;
#endif /* BSDCOMPRESS_SUPPORT */
#if PREDICTOR_SUPPORT
	    case CI_PREDICTOR_1:
		if (optlen >= CILEN_PREDICTOR_1) {
		    printer(arg, "predictor 1");
		    p += CILEN_PREDICTOR_1;
		}
		break;
	    case CI_PREDICTOR_2:
		if (optlen >= CILEN_PREDICTOR_2) {
		    printer(arg, "predictor 2");
		    p += CILEN_PREDICTOR_2;
		}
		break;
#endif /* PREDICTOR_SUPPORT */
	    default:
                break;
	    }
	    while (p < optend)
		printer(arg, " %.2x", *p++);
	    printer(arg, ">");
	}
	break;

    case TERMACK:
    case TERMREQ:
	if (len > 0 && *p >= ' ' && *p < 0x7f) {
	    ppp_print_string(p, len, printer, arg);
	    p += len;
	    len = 0;
	}
	break;
    default:
        break;
    }

    /* dump out the rest of the packet in hex */
    while (--len >= 0)
	printer(arg, " %.2x", *p++);

    return p - p0;
}