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Increased ip_reassbitmap size with 1, added assertions to catch boundary cases.

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Beautified indentation again.
This commit is contained in:
christiaans 2006-03-02 15:45:19 +00:00
parent 9e7418090d
commit 11a820458f
1 changed files with 40 additions and 30 deletions
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70
src/core/ipv4/ip_frag.c
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@ -78,7 +78,7 @@ copy_from_pbuf(struct pbuf *p, u16_t * offset,
#define IP_REASS_TMO 1000 #define IP_REASS_TMO 1000
static u8_t ip_reassbuf[IP_HLEN + IP_REASS_BUFSIZE]; static u8_t ip_reassbuf[IP_HLEN + IP_REASS_BUFSIZE];
static u8_t ip_reassbitmap[IP_REASS_BUFSIZE / (8 * 8)]; static u8_t ip_reassbitmap[IP_REASS_BUFSIZE / (8 * 8) + 1];
static const u8_t bitmap_bits[8] = { 0xff, 0x7f, 0x3f, 0x1f, static const u8_t bitmap_bits[8] = { 0xff, 0x7f, 0x3f, 0x1f,
0x0f, 0x07, 0x03, 0x01 0x0f, 0x07, 0x03, 0x01
}; };
@ -169,22 +169,28 @@ ip_reass(struct pbuf *p)
LWIP_DEBUGF(IP_REASS_DEBUG, LWIP_DEBUGF(IP_REASS_DEBUG,
("ip_reass: updating single byte in bitmap.\n")); ("ip_reass: updating single byte in bitmap.\n"));
/* If the two endpoints are in the same byte, we only update that byte. */ /* If the two endpoints are in the same byte, we only update that byte. */
LWIP_ASSERT("offset / (8 * 8) < sizeof(ip_reassbitmap)",
offset / (8 * 8) < sizeof(ip_reassbitmap));
ip_reassbitmap[offset / (8 * 8)] |= ip_reassbitmap[offset / (8 * 8)] |=
bitmap_bits[(offset / 8) & 7] & bitmap_bits[(offset / 8) & 7] &
~bitmap_bits[((offset + len) / 8) & 7]; ~bitmap_bits[((offset + len) / 8) & 7];
} else { } else {
/* If the two endpoints are in different bytes, we update the /* If the two endpoints are in different bytes, we update the
bytes in the endpoints and fill the stuff inbetween with bytes in the endpoints and fill the stuff inbetween with
0xff. */ 0xff. */
LWIP_ASSERT("offset / (8 * 8) < sizeof(ip_reassbitmap)",
offset / (8 * 8) < sizeof(ip_reassbitmap));
ip_reassbitmap[offset / (8 * 8)] |= bitmap_bits[(offset / 8) & 7]; ip_reassbitmap[offset / (8 * 8)] |= bitmap_bits[(offset / 8) & 7];
LWIP_DEBUGF(IP_REASS_DEBUG, LWIP_DEBUGF(IP_REASS_DEBUG,
("ip_reass: updating many bytes in bitmap (%"S16_F":%"S16_F").\n", ("ip_reass: updating many bytes in bitmap (%"S16_F":%"S16_F").\n",
1 + offset / (8 * 8), (offset + len) / (8 * 8))); 1 + offset / (8 * 8), (offset + len) / (8 * 8)));
for (i = 1 + offset / (8 * 8); i < (offset + len) / (8 * 8); ++i) { for (i = 1 + offset / (8 * 8); i < (offset + len) / (8 * 8); ++i) {
ip_reassbitmap[i] = 0xff; ip_reassbitmap[i] = 0xff;
} }
LWIP_ASSERT("(offset + len) / (8 * 8) < sizeof(ip_reassbitmap)",
(offset + len) / (8 * 8) < sizeof(ip_reassbitmap));
ip_reassbitmap[(offset + len) / (8 * 8)] |= ip_reassbitmap[(offset + len) / (8 * 8)] |=
~bitmap_bits[((offset + len) / 8) & 7]; ~bitmap_bits[((offset + len) / 8) & 7];
} }
/* If this fragment has the More Fragments flag set to zero, we /* If this fragment has the More Fragments flag set to zero, we
@ -207,23 +213,27 @@ ip_reass(struct pbuf *p)
if (ip_reassflags & IP_REASS_FLAG_LASTFRAG) { if (ip_reassflags & IP_REASS_FLAG_LASTFRAG) {
/* Check all bytes up to and including all but the last byte in /* Check all bytes up to and including all but the last byte in
the bitmap. */ the bitmap. */
LWIP_ASSERT("ip_reasslen / (8 * 8) - 1 < sizeof(ip_reassbitmap)",
ip_reasslen / (8 * 8) - 1 < sizeof(ip_reassbitmap));
for (i = 0; i < ip_reasslen / (8 * 8) - 1; ++i) { for (i = 0; i < ip_reasslen / (8 * 8) - 1; ++i) {
if (ip_reassbitmap[i] != 0xff) { if (ip_reassbitmap[i] != 0xff) {
LWIP_DEBUGF(IP_REASS_DEBUG, LWIP_DEBUGF(IP_REASS_DEBUG,
("ip_reass: last fragment seen, bitmap %"S16_F"/%"S16_F" failed (%"X16_F")\n", ("ip_reass: last fragment seen, bitmap %"S16_F"/%"S16_F" failed (%"X16_F")\n",
i, ip_reasslen / (8 * 8) - 1, ip_reassbitmap[i])); i, ip_reasslen / (8 * 8) - 1, ip_reassbitmap[i]));
goto nullreturn; goto nullreturn;
} }
} }
/* Check the last byte in the bitmap. It should contain just the /* Check the last byte in the bitmap. It should contain just the
right amount of bits. */ right amount of bits. */
LWIP_ASSERT("ip_reasslen / (8 * 8) < sizeof(ip_reassbitmap)",
ip_reasslen / (8 * 8) < sizeof(ip_reassbitmap));
if (ip_reassbitmap[ip_reasslen / (8 * 8)] != if (ip_reassbitmap[ip_reasslen / (8 * 8)] !=
(u8_t) ~ bitmap_bits[ip_reasslen / 8 & 7]) { (u8_t) ~ bitmap_bits[ip_reasslen / 8 & 7]) {
LWIP_DEBUGF(IP_REASS_DEBUG, LWIP_DEBUGF(IP_REASS_DEBUG,
("ip_reass: last fragment seen, bitmap %"S16_F" didn't contain %"X16_F" (%"X16_F")\n", ("ip_reass: last fragment seen, bitmap %"S16_F" didn't contain %"X16_F" (%"X16_F")\n",
ip_reasslen / (8 * 8), ~bitmap_bits[ip_reasslen / 8 & 7], ip_reasslen / (8 * 8), ~bitmap_bits[ip_reasslen / 8 & 7],
ip_reassbitmap[ip_reasslen / (8 * 8)])); ip_reassbitmap[ip_reasslen / (8 * 8)]));
goto nullreturn; goto nullreturn;
} }
/* Pretend to be a "normal" (i.e., not fragmented) IP packet /* Pretend to be a "normal" (i.e., not fragmented) IP packet
@ -242,21 +252,21 @@ ip_reass(struct pbuf *p)
pbuf_free(p); pbuf_free(p);
p = pbuf_alloc(PBUF_LINK, ip_reasslen, PBUF_POOL); p = pbuf_alloc(PBUF_LINK, ip_reasslen, PBUF_POOL);
if (p != NULL) { if (p != NULL) {
i = 0; i = 0;
for (q = p; q != NULL; q = q->next) { for (q = p; q != NULL; q = q->next) {
/* Copy enough bytes to fill this pbuf in the chain. The /* Copy enough bytes to fill this pbuf in the chain. The
available data in the pbuf is given by the q->len variable. */ available data in the pbuf is given by the q->len variable. */
LWIP_DEBUGF(IP_REASS_DEBUG, LWIP_DEBUGF(IP_REASS_DEBUG,
("ip_reass: memcpy from %p (%"S16_F") to %p, %"S16_F" bytes\n", ("ip_reass: memcpy from %p (%"S16_F") to %p, %"S16_F" bytes\n",
(void *)&ip_reassbuf[i], i, q->payload, (void *)&ip_reassbuf[i], i, q->payload,
q->len > ip_reasslen - i ? ip_reasslen - i : q->len)); q->len > ip_reasslen - i ? ip_reasslen - i : q->len));
memcpy(q->payload, &ip_reassbuf[i], memcpy(q->payload, &ip_reassbuf[i],
q->len > ip_reasslen - i ? ip_reasslen - i : q->len); q->len > ip_reasslen - i ? ip_reasslen - i : q->len);
i += q->len; i += q->len;
} }
IPFRAG_STATS_INC(ip_frag.fw); IPFRAG_STATS_INC(ip_frag.fw);
} else { } else {
IPFRAG_STATS_INC(ip_frag.memerr); IPFRAG_STATS_INC(ip_frag.memerr);
} }
LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_reass: p %p\n", (void*)p)); LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_reass: p %p\n", (void*)p));
return p; return p;