static int ipcp_rejci()

in net/ip/lwip_base/src/netif/ppp/ipcp.c [1341:1492]

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

static int ipcp_rejci(fsm *f, u_char *p, int len) {
    ppp_pcb *pcb = f->pcb;
    ipcp_options *go = &pcb->ipcp_gotoptions;
    u_char cilen;
#if VJ_SUPPORT
    u_char cimaxslotindex, ciflag;
    u_short cishort;
#endif /* VJ_SUPPORT */
    u32_t cilong;
    ipcp_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 REJCIADDRS(opt, neg, val1, val2) \
    if ((neg) && \
	(cilen = p[1]) == CILEN_ADDRS && \
	len >= cilen && \
	p[0] == opt) { \
	u32_t l; \
	len -= cilen; \
	INCPTR(2, p); \
	GETLONG(l, p); \
	cilong = lwip_htonl(l); \
	/* Check rejected value. */ \
	if (cilong != val1) \
	    goto bad; \
	GETLONG(l, p); \
	cilong = lwip_htonl(l); \
	/* Check rejected value. */ \
	if (cilong != val2) \
	    goto bad; \
	try_.old_addrs = 0; \
    }

#if VJ_SUPPORT
#define REJCIVJ(opt, neg, val, old, maxslot, cflag) \
    if (go->neg && \
	p[1] == (old? CILEN_COMPRESS : CILEN_VJ) && \
	len >= p[1] && \
	p[0] == opt) { \
	len -= p[1]; \
	INCPTR(2, p); \
	GETSHORT(cishort, p); \
	/* Check rejected value. */  \
	if (cishort != val) \
	    goto bad; \
	if (!old) { \
	   GETCHAR(cimaxslotindex, p); \
	   if (cimaxslotindex != maxslot) \
	     goto bad; \
	   GETCHAR(ciflag, p); \
	   if (ciflag != cflag) \
	     goto bad; \
        } \
	try_.neg = 0; \
     }
#endif /* VJ_SUPPORT */

#define REJCIADDR(opt, neg, val) \
    if (go->neg && \
	(cilen = p[1]) == CILEN_ADDR && \
	len >= cilen && \
	p[0] == opt) { \
	u32_t l; \
	len -= cilen; \
	INCPTR(2, p); \
	GETLONG(l, p); \
	cilong = lwip_htonl(l); \
	/* Check rejected value. */ \
	if (cilong != val) \
	    goto bad; \
	try_.neg = 0; \
    }

#if LWIP_DNS
#define REJCIDNS(opt, neg, dnsaddr) \
    if (go->neg && \
	((cilen = p[1]) == CILEN_ADDR) && \
	len >= cilen && \
	p[0] == opt) { \
	u32_t l; \
	len -= cilen; \
	INCPTR(2, p); \
	GETLONG(l, p); \
	cilong = lwip_htonl(l); \
	/* Check rejected value. */ \
	if (cilong != dnsaddr) \
	    goto bad; \
	try_.neg = 0; \
    }
#endif /* LWIP_DNS */

#if 0 /* UNUSED - WINS */
#define REJCIWINS(opt, addr) \
    if (addr && \
	((cilen = p[1]) == CILEN_ADDR) && \
	len >= cilen && \
	p[0] == opt) { \
	u32_t l; \
	len -= cilen; \
	INCPTR(2, p); \
	GETLONG(l, p); \
	cilong = lwip_htonl(l); \
	/* Check rejected value. */ \
	if (cilong != addr) \
	    goto bad; \
	try_.winsaddr[opt == CI_MS_WINS2] = 0; \
    }
#endif /* UNUSED - WINS */

    REJCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs,
	       go->ouraddr, go->hisaddr);

#if VJ_SUPPORT
    REJCIVJ(CI_COMPRESSTYPE, neg_vj, go->vj_protocol, go->old_vj,
	    go->maxslotindex, go->cflag);
#endif /* VJ_SUPPORT */

    REJCIADDR(CI_ADDR, neg_addr, go->ouraddr);

#if LWIP_DNS
    REJCIDNS(CI_MS_DNS1, req_dns1, go->dnsaddr[0]);

    REJCIDNS(CI_MS_DNS2, req_dns2, go->dnsaddr[1]);
#endif /* LWIP_DNS */

#if 0 /* UNUSED - WINS */
    REJCIWINS(CI_MS_WINS1, go->winsaddr[0]);

    REJCIWINS(CI_MS_WINS2, go->winsaddr[1]);
#endif /* UNUSED - WINS */

    /*
     * 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:
    IPCPDEBUG(("ipcp_rejci: received bad Reject!"));
    return 0;
}