static int lcp_ackci()

in net/ip/lwip_base/src/netif/ppp/lcp.c [947:1115]

• 158 lines of code
• 51 McCabe index (conditional complexity)

static int lcp_ackci(fsm *f, u_char *p, int len) {
    ppp_pcb *pcb = f->pcb;
    lcp_options *go = &pcb->lcp_gotoptions;
    u_char cilen, citype, cichar;
    u_short cishort;
    u32_t cilong;

    /*
     * CIs must be in exactly the same order that we sent.
     * Check packet length and CI length at each step.
     * If we find any deviations, then this packet is bad.
     */
#define ACKCIVOID(opt, neg) \
    if (neg) { \
	if ((len -= CILEN_VOID) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_VOID || \
	    citype != opt) \
	    goto bad; \
    }
#define ACKCISHORT(opt, neg, val) \
    if (neg) { \
	if ((len -= CILEN_SHORT) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_SHORT || \
	    citype != opt) \
	    goto bad; \
	GETSHORT(cishort, p); \
	if (cishort != val) \
	    goto bad; \
    }
#define ACKCICHAR(opt, neg, val) \
    if (neg) { \
	if ((len -= CILEN_CHAR) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_CHAR || \
	    citype != opt) \
	    goto bad; \
	GETCHAR(cichar, p); \
	if (cichar != val) \
	    goto bad; \
    }
#if CHAP_SUPPORT
#define ACKCICHAP(opt, neg, val) \
    if (neg) { \
	if ((len -= CILEN_CHAP) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_CHAP || \
	    citype != (opt)) \
	    goto bad; \
	GETSHORT(cishort, p); \
	if (cishort != PPP_CHAP) \
	    goto bad; \
	GETCHAR(cichar, p); \
	if (cichar != (CHAP_DIGEST(val))) \
	  goto bad; \
    }
#endif /* CHAP_SUPPORT */
#define ACKCILONG(opt, neg, val) \
    if (neg) { \
	if ((len -= CILEN_LONG) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_LONG || \
	    citype != opt) \
	    goto bad; \
	GETLONG(cilong, p); \
	if (cilong != val) \
	    goto bad; \
    }
#if LQR_SUPPORT
#define ACKCILQR(opt, neg, val) \
    if (neg) { \
	if ((len -= CILEN_LQR) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_LQR || \
	    citype != opt) \
	    goto bad; \
	GETSHORT(cishort, p); \
	if (cishort != PPP_LQR) \
	    goto bad; \
	GETLONG(cilong, p); \
	if (cilong != val) \
	  goto bad; \
    }
#endif /* LQR_SUPPORT */
#define ACKCIENDP(opt, neg, class, val, vlen) \
    if (neg) { \
	int i; \
	if ((len -= CILEN_CHAR + vlen) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_CHAR + vlen || \
	    citype != opt) \
	    goto bad; \
	GETCHAR(cichar, p); \
	if (cichar != class) \
	    goto bad; \
	for (i = 0; i < vlen; ++i) { \
	    GETCHAR(cichar, p); \
	    if (cichar != val[i]) \
		goto bad; \
	} \
    }

    ACKCISHORT(CI_MRU, go->neg_mru && go->mru != PPP_DEFMRU, go->mru);
    ACKCILONG(CI_ASYNCMAP, go->neg_asyncmap && go->asyncmap != 0xFFFFFFFF,
	      go->asyncmap);
#if EAP_SUPPORT
    ACKCISHORT(CI_AUTHTYPE, go->neg_eap, PPP_EAP);
#endif /* EAP_SUPPORT */
#if CHAP_SUPPORT /* cannot be improved, embedding a directive within macro arguments is not portable */
#if EAP_SUPPORT
    ACKCICHAP(CI_AUTHTYPE, !go->neg_eap && go->neg_chap, go->chap_mdtype);
#endif /* EAP_SUPPORT */
#if !EAP_SUPPORT
    ACKCICHAP(CI_AUTHTYPE, go->neg_chap, go->chap_mdtype);
#endif /* !EAP_SUPPORT */
#endif /* CHAP_SUPPORT */
#if PAP_SUPPORT /* cannot be improved, embedding a directive within macro arguments is not portable */
#if EAP_SUPPORT && CHAP_SUPPORT
    ACKCISHORT(CI_AUTHTYPE, !go->neg_eap && !go->neg_chap && go->neg_upap, PPP_PAP);
#endif /* EAP_SUPPORT && CHAP_SUPPORT */
#if EAP_SUPPORT && !CHAP_SUPPORT
    ACKCISHORT(CI_AUTHTYPE, !go->neg_eap && go->neg_upap, PPP_PAP);
#endif /* EAP_SUPPORT && !CHAP_SUPPORT */
#if !EAP_SUPPORT && CHAP_SUPPORT
    ACKCISHORT(CI_AUTHTYPE, !go->neg_chap && go->neg_upap, PPP_PAP);
#endif /* !EAP_SUPPORT && CHAP_SUPPORT */
#if !EAP_SUPPORT && !CHAP_SUPPORT
    ACKCISHORT(CI_AUTHTYPE, go->neg_upap, PPP_PAP);
#endif /* !EAP_SUPPORT && !CHAP_SUPPORT */
#endif /* PAP_SUPPORT */
#if LQR_SUPPORT
    ACKCILQR(CI_QUALITY, go->neg_lqr, go->lqr_period);
#endif /* LQR_SUPPORT */
    ACKCICHAR(CI_CALLBACK, go->neg_cbcp, CBCP_OPT);
    ACKCILONG(CI_MAGICNUMBER, go->neg_magicnumber, go->magicnumber);
    ACKCIVOID(CI_PCOMPRESSION, go->neg_pcompression);
    ACKCIVOID(CI_ACCOMPRESSION, go->neg_accompression);
#ifdef HAVE_MULTILINK
    ACKCISHORT(CI_MRRU, go->neg_mrru, go->mrru);
#endif /* HAVE_MULTILINK */
    ACKCIVOID(CI_SSNHF, go->neg_ssnhf);
    ACKCIENDP(CI_EPDISC, go->neg_endpoint, go->endpoint.class_,
	      go->endpoint.value, go->endpoint.length);

    /*
     * If there are any remaining CIs, then this packet is bad.
     */
    if (len != 0)
	goto bad;
    return (1);
bad:
    LCPDEBUG(("lcp_acki: received bad Ack!"));
    return (0);
}