diff options
Diffstat (limited to 'zebra/kernel_socket.c')
| -rw-r--r-- | zebra/kernel_socket.c | 161 |
1 files changed, 68 insertions, 93 deletions
diff --git a/zebra/kernel_socket.c b/zebra/kernel_socket.c index 59bb023b..b8dfcc7d 100644 --- a/zebra/kernel_socket.c +++ b/zebra/kernel_socket.c @@ -40,15 +40,29 @@ extern struct zebra_privs_t zserv_privs; extern struct zebra_t zebrad; -/* Socket length roundup function. */ +/* + * Given a sockaddr length, round it up to include pad bytes following + * it. Assumes the kernel pads to sizeof(long). + * + * XXX: why is ROUNDUP(0) sizeof(long)? 0 is an illegal sockaddr + * length anyway (< sizeof (struct sockaddr)), so this shouldn't + * matter. + */ #define ROUNDUP(a) \ ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long)) -/* And this macro is wrapper for handling sa_len. */ +/* + * Given a pointer (sockaddr or void *), return the number of bytes + * taken up by the sockaddr and any padding needed for alignment. + */ #if defined(HAVE_SA_LEN) -#define WRAPUP(X) ROUNDUP(((struct sockaddr *)(X))->sa_len) +#define SAROUNDUP(X) ROUNDUP(((struct sockaddr *)(X))->sa_len) #elif defined(HAVE_IPV6) -#define WRAPUP(X) \ +/* + * One would hope all fixed-size structure definitions are aligned, + * but round them up nonetheless. + */ +#define SAROUNDUP(X) \ do { \ (((struct sockaddr *)(X))->sa_family == AF_INET ? \ ROUNDUP(sizeof(struct sockaddr_in)):\ @@ -58,7 +72,7 @@ extern struct zebra_t zebrad; ROUNDUP(sizeof(struct sockaddr_dl)) : sizeof(struct sockaddr)))) \ } while (0) #else /* HAVE_IPV6 */ -#define WRAPUP(X) \ +#define SAROUNDUP(X) \ (((struct sockaddr *)(X))->sa_family == AF_INET ? \ ROUNDUP(sizeof(struct sockaddr_in)):\ (((struct sockaddr *)(X))->sa_family == AF_LINK ? \ @@ -221,6 +235,8 @@ ifm_read (struct if_msghdr *ifm) { struct interface *ifp = NULL; struct sockaddr_dl *sdl = NULL; + void *cp; + unsigned int i; char ifname[IFNAMSIZ]; /* paranoia: sanity check structure */ @@ -232,91 +248,55 @@ ifm_read (struct if_msghdr *ifm) } /* - * Check for a sockaddr_dl following the message. + * Check for a sockaddr_dl following the message. First, point to + * where a socakddr might be if one follows the message. */ -#ifdef SUNOS_5 - int i; - struct sockaddr *sa; - u_char *cp = (u_char *)(ifm + 1); + cp = (void *)(ifm + 1); +#ifdef SUNOS_5 /* + * XXX This behavior should be narrowed to only the kernel versions + * for which the structures returned do not match the headers. + * * if_msghdr_t on 64 bit kernels in Solaris 9 and earlier versions - * is 12 bytes larger than the 32 bit version, so make adjustment - * here. + * is 12 bytes larger than the 32 bit version. */ - sa = (struct sockaddr *)cp; - if (sa->sa_family == AF_UNSPEC) + if (((struct sockaddr *) cp)->sa_family == AF_UNSPEC) cp = cp + 12; +#endif + /* + * Check for each sockaddr in turn, advancing over it. After this + * loop, sdl should point to a sockaddr_dl iff one was present. + */ for (i = 1; i != 0; i <<= 1) { - if (i & ifm->ifm_addrs) + if (i & ifm->ifm_addrs) { - sa = (struct sockaddr *)cp; - cp += WRAPUP(sa); - if (i & RTA_IFP) + if (i == RTA_IFP) { - sdl = (struct sockaddr_dl *)sa; + sdl = (struct sockaddr_dl *)cp; break; } + cp += SAROUNDUP(cp); } } - /* - * After here, If RTA_IFP was set in ifm_addrs, sdl should point to - * the sockaddr_dl. - */ -#else - /* sockaddrs_present? */ - if (ifm->ifm_addrs) + + /* Ensure that sdl, if present, is actually a sockaddr_dl. */ + if (sdl != NULL && sdl->sdl_family != AF_LINK) { - if (ifm->ifm_addrs == RTA_IFP) - { - /* just the one we want */ - sdl = (struct sockaddr_dl *)(ifm + 1); - } - else - { - /* - * Not strictly an error, but more complicated parsing than - * is implemented is required to handle this case. - */ - zlog_err ("ifm_read: addrs %x != RTA_IFP (unhandled, ignoring)\n", - ifm->ifm_addrs); - return -1; - } + zlog_err ("ifm_read: sockaddr_dl bad AF %d\n", + sdl->sdl_family); + return -1; } - /* - * Past here, either ifm_addrs == 0 or ifm_addrs == RTA_IFP and sdl - * points to a RTA_IFP sockaddr. - */ -#endif - - /* Check that sdl, if present, is actually a sockaddr_dl before use. */ - if (sdl != NULL) - switch (sdl->sdl_family) - { - case AF_LINK: - /* Standard AF for link-layer address sockaddrs. */ - case AF_DLI: - /* - * XXX Comment in NetBSD net/if_dl.h says AF_DLI, but this - * seems wrong. Accept it for now. - */ - break; - - default: - zlog_err ("ifm_read: sockaddr_dl bad AF %d\n", - sdl->sdl_family); - return -1; - } /* - * Look up on ifindex. This is useful if this is an up/down - * notification for an interface of which we are already aware. - * (This happens on NetBSD 1.6.2, for example.) + * Look up on ifindex first, because ifindices are the primary + * handle for interfaces across the user/kernel boundary. (Some + * messages, such as up/down status changes on NetBSD, do not + * include a sockaddr_dl). */ - if (ifp == NULL) - ifp = if_lookup_by_index (ifm->ifm_index); + ifp = if_lookup_by_index (ifm->ifm_index); /* * If lookup by index was unsuccessful and we have a name, try @@ -348,28 +328,25 @@ ifm_read (struct if_msghdr *ifm) */ if ((ifp == NULL) || (ifp->ifindex == -1)) { - /* Check interface's address.*/ - if (! (ifm->ifm_addrs & RTA_IFP)) - { - zlog_warn ("Interface index %d (new) missing RTA_IFP sockaddr\n", - ifm->ifm_index); - return -1; - } - /* - * paranoia: sdl-finding code above guarantees that sdl is - * non-NULL and valid if RTA_IFP is set in ifm_addrs, so this - * check is in theory not necessary. + * To create or fill in an interface, a sockaddr_dl (via + * RTA_IFP) is required. */ if (sdl == NULL) { - zlog_warn ("ifm_read: no sockaddr_dl present"); + zlog_warn ("Interface index %d (new) missing RTA_IFP sockaddr_dl\n", + ifm->ifm_index); return -1; } if (ifp == NULL) + /* Interface that zebra was not previously aware of, so create. */ ifp = if_create (sdl->sdl_data, sdl->sdl_nlen); + /* + * Fill in newly created interface structure, or larval + * structure with ifindex -1. + */ ifp->ifindex = ifm->ifm_index; ifp->flags = ifm->ifm_flags; #if defined(__bsdi__) @@ -379,13 +356,11 @@ ifm_read (struct if_msghdr *ifm) #endif /* __bsdi__ */ if_get_metric (ifp); - /* Fetch hardware address. */ - if (sdl->sdl_family != AF_LINK) - { - zlog_warn ("sockaddr_dl->sdl_family is not AF_LINK"); - return -1; - } - /* XXX sockaddr_dl can be larger than base structure */ + /* + * XXX sockaddr_dl contents can be larger than the structure + * definition, so the user of the stored structure must be + * careful not to read off the end. + */ memcpy (&ifp->sdl, sdl, sizeof (struct sockaddr_dl)); if_add_update (ifp); @@ -438,7 +413,7 @@ ifam_read_mesg (struct ifa_msghdr *ifm, #define IFAMADDRGET(X,R) \ if (ifm->ifam_addrs & (R)) \ { \ - int len = WRAPUP(pnt); \ + int len = SAROUNDUP(pnt); \ if (((X) != NULL) && af_check (((struct sockaddr *)pnt)->sa_family)) \ memcpy ((caddr_t)(X), pnt, len); \ pnt += len; \ @@ -446,7 +421,7 @@ ifam_read_mesg (struct ifa_msghdr *ifm, #define IFAMMASKGET(X,R) \ if (ifm->ifam_addrs & (R)) \ { \ - int len = WRAPUP(pnt); \ + int len = SAROUNDUP(pnt); \ if ((X) != NULL) \ memcpy ((caddr_t)(X), pnt, len); \ pnt += len; \ @@ -554,7 +529,7 @@ rtm_read_mesg (struct rt_msghdr *rtm, #define RTMADDRGET(X,R) \ if (rtm->rtm_addrs & (R)) \ { \ - int len = WRAPUP (pnt); \ + int len = SAROUNDUP (pnt); \ if (((X) != NULL) && af_check (((struct sockaddr *)pnt)->sa_family)) \ memcpy ((caddr_t)(X), pnt, len); \ pnt += len; \ @@ -562,7 +537,7 @@ rtm_read_mesg (struct rt_msghdr *rtm, #define RTMMASKGET(X,R) \ if (rtm->rtm_addrs & (R)) \ { \ - int len = WRAPUP (pnt); \ + int len = SAROUNDUP (pnt); \ if ((X) != NULL) \ memcpy ((caddr_t)(X), pnt, len); \ pnt += len; \ |