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Fixed bug #20429: use the new pbuf_copy_partial instead of the old copy_from_pbuf, which illegally modified the given pbuf; Introduced pbuf_copy_partial, making netbuf_copy_partial use this function.

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This commit is contained in:
goldsimon
2007-07-25 18:53:45 +00:00
parent 8be76ed450
commit f9c30017b0
6 changed files with 60 additions and 82 deletions
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38
src/core/ipv4/ip_frag.c
View File

@@ -59,40 +59,6 @@ static u8_t ip_reassflags;
static u8_t ip_reasstmr;
#endif /* IP_REASSEMBLY */
#if IP_REASSEMBLY || (IP_FRAG && IP_FRAG_USES_STATIC_BUF)
/*
* Copy len bytes from offset in pbuf to buffer
*
* helper used by both ip_reass and ip_frag
*
* @param p pbuf chain to copy from
* @param offset offset in bytes into the pbuf chain which should be skipped
* before starting to copy
* @param buffer destination to copy the data
* @param len number of bytes to copy (starting from offset)
* @return pointer to one pbuf in the chain p from which copied last
*/
static struct pbuf *
copy_from_pbuf(struct pbuf *p, u16_t *offset, u8_t *buffer, u16_t len)
{
u16_t l;
p->payload = (u8_t *)p->payload + *offset;
p->len -= *offset;
while (len) {
l = len < p->len ? len : p->len;
MEMCPY(buffer, p->payload, l);
buffer += l;
len -= l;
if (len)
p = p->next;
else
*offset = l;
}
return p;
}
#endif /* IP_REASSEMBLY || IP_FRAG_USES_STATIC_BUF */
#if IP_REASSEMBLY
/**
* Initializes IP reassembly states.
@@ -187,7 +153,7 @@ ip_reass(struct pbuf *p)
("ip_reass: copying with offset %"S16_F" into %"S16_F":%"S16_F"\n", offset,
IP_HLEN + offset, IP_HLEN + offset + len));
i = IPH_HL(fraghdr) * 4;
copy_from_pbuf(p, &i, &ip_reassbuf[IP_HLEN + offset], len);
pbuf_copy_partial(p, &ip_reassbuf[IP_HLEN + offset], len, i);
/* Update the bitmap. */
if (offset / (8 * 8) == (offset + len) / (8 * 8)) {
@@ -392,7 +358,7 @@ ip_frag(struct pbuf *p, struct netif *netif, struct ip_addr *dest)
cop = last ? left : nfb * 8;
#if IP_FRAG_USES_STATIC_BUF
p = copy_from_pbuf(p, &poff, (u8_t *) iphdr + IP_HLEN, cop);
poff += pbuf_copy_partial(p, (u8_t*)iphdr + IP_HLEN, cop, poff);
#else /* IP_FRAG_USES_STATIC_BUF */
/* When not using a static buffer, create a chain of pbufs.
* The first will be a PBUF_RAM holding the link and IP header.

47
src/core/pbuf.c
View File

@@ -735,3 +735,50 @@ pbuf_copy(struct pbuf *p_to, struct pbuf *p_from)
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE | 1, ("pbuf_copy: end of chain reached.\n"));
return ERR_OK;
}
/**
* Copy (part of) the contents of a packet buffer
* to an application supplied buffer.
*
* @param buf the pbuf from which to copy data
* @param dataptr the application supplied buffer
* @param len length of data to copy (dataptr must be big enough)
* @param offset offset into the packet buffer from where to begin copying len bytes
*/
u16_t
pbuf_copy_partial(struct pbuf *buf, void *dataptr, u16_t len, u16_t offset)
{
struct pbuf *p;
u16_t left;
u16_t buf_copy_len;
u16_t copied_total = 0;
LWIP_ERROR("netbuf_copy_partial: invalid buf", (buf != NULL), return 0;);
LWIP_ERROR("netbuf_copy_partial: invalid dataptr", (dataptr != NULL), return 0;);
left = 0;
if((buf == NULL) || (dataptr == NULL)) {
return 0;
}
/* Note some systems use byte copy if dataptr or one of the pbuf payload pointers are unaligned. */
for(p = buf; len != 0 && p != NULL; p = p->next) {
if ((offset != 0) && (offset >= p->len)) {
/* don't copy from this buffer -> on to the next */
offset -= p->len;
} else {
/* copy from this buffer. maybe only partially. */
buf_copy_len = p->len - offset;
if (buf_copy_len > len)
buf_copy_len = len;
/* copy the necessary parts of the buffer */
MEMCPY(&((char*)dataptr)[left], &((char*)p->payload)[offset], buf_copy_len);
copied_total += buf_copy_len;
left += buf_copy_len;
len -= buf_copy_len;
offset = 0;
}
}
return copied_total;
}