static int ipcp_ackci()

in net/ip/lwip_base/src/netif/ppp/ipcp.c [921:1064]

• 121 lines of code
• 32 McCabe index (conditional complexity)

static int ipcp_ackci(fsm *f, u_char *p, int len) {
    ppp_pcb *pcb = f->pcb;
    ipcp_options *go = &pcb->ipcp_gotoptions;
    u_short cilen, citype;
    u32_t cilong;
#if VJ_SUPPORT
    u_short cishort;
    u_char cimaxslotindex, cicflag;
#endif /* VJ_SUPPORT */

    /*
     * 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 ACKCIADDRS(opt, neg, val1, val2) \
    if (neg) { \
	u32_t l; \
	if ((len -= CILEN_ADDRS) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_ADDRS || \
	    citype != opt) \
	    goto bad; \
	GETLONG(l, p); \
	cilong = lwip_htonl(l); \
	if (val1 != cilong) \
	    goto bad; \
	GETLONG(l, p); \
	cilong = lwip_htonl(l); \
	if (val2 != cilong) \
	    goto bad; \
    }

#if VJ_SUPPORT
#define ACKCIVJ(opt, neg, val, old, maxslotindex, cflag) \
    if (neg) { \
	int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \
	if ((len -= vjlen) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != vjlen || \
	    citype != opt)  \
	    goto bad; \
	GETSHORT(cishort, p); \
	if (cishort != val) \
	    goto bad; \
	if (!old) { \
	    GETCHAR(cimaxslotindex, p); \
	    if (cimaxslotindex != maxslotindex) \
		goto bad; \
	    GETCHAR(cicflag, p); \
	    if (cicflag != cflag) \
		goto bad; \
	} \
    }
#endif /* VJ_SUPPORT */

#define ACKCIADDR(opt, neg, val) \
    if (neg) { \
	u32_t l; \
	if ((len -= CILEN_ADDR) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_ADDR || \
	    citype != opt) \
	    goto bad; \
	GETLONG(l, p); \
	cilong = lwip_htonl(l); \
	if (val != cilong) \
	    goto bad; \
    }

#if LWIP_DNS
#define ACKCIDNS(opt, neg, addr) \
    if (neg) { \
	u32_t l; \
	if ((len -= CILEN_ADDR) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_ADDR || citype != opt) \
	    goto bad; \
	GETLONG(l, p); \
	cilong = lwip_htonl(l); \
	if (addr != cilong) \
	    goto bad; \
    }
#endif /* LWIP_DNS */

#if 0 /* UNUSED - WINS */
#define ACKCIWINS(opt, addr) \
    if (addr) { \
	u32_t l; \
	if ((len -= CILEN_ADDR) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_ADDR || citype != opt) \
	    goto bad; \
	GETLONG(l, p); \
	cilong = lwip_htonl(l); \
	if (addr != cilong) \
	    goto bad; \
    }
#endif /* UNUSED - WINS */

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

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

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

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

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

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

    ACKCIWINS(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;
    return (1);

bad:
    IPCPDEBUG(("ipcp_ackci: received bad Ack!"));
    return (0);
}