static int lcp_rejci()

in net/ip/lwip_base/src/netif/ppp/lcp.c [1589:1807]

• 198 lines of code
• 69 McCabe index (conditional complexity)

static int lcp_rejci(fsm *f, u_char *p, int len) {
    ppp_pcb *pcb = f->pcb;
    lcp_options *go = &pcb->lcp_gotoptions;
    u_char cichar;
    u_short cishort;
    u32_t cilong;
    lcp_options try_;		/* options to request next time */

    try_ = *go;

    /*
     * Any Rejected 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 REJCIVOID(opt, neg) \
    if (go->neg && \
	len >= CILEN_VOID && \
	p[1] == CILEN_VOID && \
	p[0] == opt) { \
	len -= CILEN_VOID; \
	INCPTR(CILEN_VOID, p); \
	try_.neg = 0; \
    }
#define REJCISHORT(opt, neg, val) \
    if (go->neg && \
	len >= CILEN_SHORT && \
	p[1] == CILEN_SHORT && \
	p[0] == opt) { \
	len -= CILEN_SHORT; \
	INCPTR(2, p); \
	GETSHORT(cishort, p); \
	/* Check rejected value. */ \
	if (cishort != val) \
	    goto bad; \
	try_.neg = 0; \
    }

#if CHAP_SUPPORT && EAP_SUPPORT && PAP_SUPPORT
#define REJCICHAP(opt, neg, val) \
    if (go->neg && \
	len >= CILEN_CHAP && \
	p[1] == CILEN_CHAP && \
	p[0] == opt) { \
	len -= CILEN_CHAP; \
	INCPTR(2, p); \
	GETSHORT(cishort, p); \
	GETCHAR(cichar, p); \
	/* Check rejected value. */ \
	if ((cishort != PPP_CHAP) || (cichar != (CHAP_DIGEST(val)))) \
	    goto bad; \
	try_.neg = 0; \
	try_.neg_eap = try_.neg_upap = 0; \
    }
#endif /* CHAP_SUPPORT && EAP_SUPPORT && PAP_SUPPORT */

#if CHAP_SUPPORT && !EAP_SUPPORT && PAP_SUPPORT
#define REJCICHAP(opt, neg, val) \
    if (go->neg && \
	len >= CILEN_CHAP && \
	p[1] == CILEN_CHAP && \
	p[0] == opt) { \
	len -= CILEN_CHAP; \
	INCPTR(2, p); \
	GETSHORT(cishort, p); \
	GETCHAR(cichar, p); \
	/* Check rejected value. */ \
	if ((cishort != PPP_CHAP) || (cichar != (CHAP_DIGEST(val)))) \
	    goto bad; \
	try_.neg = 0; \
	try_.neg_upap = 0; \
    }
#endif /* CHAP_SUPPORT && !EAP_SUPPORT && PAP_SUPPORT */

#if CHAP_SUPPORT && EAP_SUPPORT && !PAP_SUPPORT
#define REJCICHAP(opt, neg, val) \
    if (go->neg && \
	len >= CILEN_CHAP && \
	p[1] == CILEN_CHAP && \
	p[0] == opt) { \
	len -= CILEN_CHAP; \
	INCPTR(2, p); \
	GETSHORT(cishort, p); \
	GETCHAR(cichar, p); \
	/* Check rejected value. */ \
	if ((cishort != PPP_CHAP) || (cichar != (CHAP_DIGEST(val)))) \
	    goto bad; \
	try_.neg = 0; \
	try_.neg_eap = 0; \
    }
#endif /* CHAP_SUPPORT && EAP_SUPPORT && !PAP_SUPPORT */

#if CHAP_SUPPORT && !EAP_SUPPORT && !PAP_SUPPORT
#define REJCICHAP(opt, neg, val) \
    if (go->neg && \
	len >= CILEN_CHAP && \
	p[1] == CILEN_CHAP && \
	p[0] == opt) { \
	len -= CILEN_CHAP; \
	INCPTR(2, p); \
	GETSHORT(cishort, p); \
	GETCHAR(cichar, p); \
	/* Check rejected value. */ \
	if ((cishort != PPP_CHAP) || (cichar != (CHAP_DIGEST(val)))) \
	    goto bad; \
	try_.neg = 0; \
    }
#endif /* CHAP_SUPPORT && !EAP_SUPPORT && !PAP_SUPPORT */

#define REJCILONG(opt, neg, val) \
    if (go->neg && \
	len >= CILEN_LONG && \
	p[1] == CILEN_LONG && \
	p[0] == opt) { \
	len -= CILEN_LONG; \
	INCPTR(2, p); \
	GETLONG(cilong, p); \
	/* Check rejected value. */ \
	if (cilong != val) \
	    goto bad; \
	try_.neg = 0; \
    }
#if LQR_SUPPORT
#define REJCILQR(opt, neg, val) \
    if (go->neg && \
	len >= CILEN_LQR && \
	p[1] == CILEN_LQR && \
	p[0] == opt) { \
	len -= CILEN_LQR; \
	INCPTR(2, p); \
	GETSHORT(cishort, p); \
	GETLONG(cilong, p); \
	/* Check rejected value. */ \
	if (cishort != PPP_LQR || cilong != val) \
	    goto bad; \
	try_.neg = 0; \
    }
#endif /* LQR_SUPPORT */
#define REJCICBCP(opt, neg, val) \
    if (go->neg && \
	len >= CILEN_CBCP && \
	p[1] == CILEN_CBCP && \
	p[0] == opt) { \
	len -= CILEN_CBCP; \
	INCPTR(2, p); \
	GETCHAR(cichar, p); \
	/* Check rejected value. */ \
	if (cichar != val) \
	    goto bad; \
	try_.neg = 0; \
    }
#define REJCIENDP(opt, neg, class, val, vlen) \
    if (go->neg && \
	len >= CILEN_CHAR + vlen && \
	p[0] == opt && \
	p[1] == CILEN_CHAR + vlen) { \
	int i; \
	len -= CILEN_CHAR + vlen; \
	INCPTR(2, p); \
	GETCHAR(cichar, p); \
	if (cichar != class) \
	    goto bad; \
	for (i = 0; i < vlen; ++i) { \
	    GETCHAR(cichar, p); \
	    if (cichar != val[i]) \
		goto bad; \
	} \
	try_.neg = 0; \
    }

    REJCISHORT(CI_MRU, neg_mru, go->mru);
    REJCILONG(CI_ASYNCMAP, neg_asyncmap, go->asyncmap);
#if EAP_SUPPORT
    REJCISHORT(CI_AUTHTYPE, neg_eap, PPP_EAP);
    if (!go->neg_eap) {
#endif /* EAP_SUPPORT */
#if CHAP_SUPPORT
	REJCICHAP(CI_AUTHTYPE, neg_chap, go->chap_mdtype);
	if (!go->neg_chap) {
#endif /* CHAP_SUPPORT */
#if PAP_SUPPORT
	    REJCISHORT(CI_AUTHTYPE, neg_upap, PPP_PAP);
#endif /* PAP_SUPPORT */
#if CHAP_SUPPORT
	}
#endif /* CHAP_SUPPORT */
#if EAP_SUPPORT
    }
#endif /* EAP_SUPPORT */
#if LQR_SUPPORT
    REJCILQR(CI_QUALITY, neg_lqr, go->lqr_period);
#endif /* LQR_SUPPORT */
    REJCICBCP(CI_CALLBACK, neg_cbcp, CBCP_OPT);
    REJCILONG(CI_MAGICNUMBER, neg_magicnumber, go->magicnumber);
    REJCIVOID(CI_PCOMPRESSION, neg_pcompression);
    REJCIVOID(CI_ACCOMPRESSION, neg_accompression);
#ifdef HAVE_MULTILINK
    REJCISHORT(CI_MRRU, neg_mrru, go->mrru);
#endif /* HAVE_MULTILINK */
    REJCIVOID(CI_SSNHF, neg_ssnhf);
    REJCIENDP(CI_EPDISC, 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;
    /*
     * Now we can update state.
     */
    if (f->state != PPP_FSM_OPENED)
	*go = try_;
    return 1;

bad:
    LCPDEBUG(("lcp_rejci: received bad Reject!"));
    return 0;
}