netif: Add proper lock protect for accessing netif->loop_first

All the reset part of the code accessing netif->loop_first has lock protection,
the only missing part is "while (netif->loop_first != NULL)".
Fix it by adding lock protect around the while loop.

Also convert the code to use while{} loop instead of do .. while{} loop,
then we can avoid NULL test for in pointer in each loop and reduce a level of indent.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
This commit is contained in:
Axel Lin 2016-11-25 19:47:34 +08:00 committed by Dirk Ziegelmeier
parent 0e07ed4b13
commit 1d4cbe768d

View File

@ -904,7 +904,6 @@ netif_loop_output_ipv6(struct netif *netif, struct pbuf *p, const ip6_addr_t* ad
void
netif_poll(struct netif *netif)
{
struct pbuf *in;
/* If we have a loopif, SNMP counters are adjusted for it,
* if not they are adjusted for 'netif'. */
#if MIB2_STATS
@ -916,56 +915,52 @@ netif_poll(struct netif *netif)
#endif /* MIB2_STATS */
SYS_ARCH_DECL_PROTECT(lev);
do {
/* Get a packet from the list. With SYS_LIGHTWEIGHT_PROT=1, this is protected */
SYS_ARCH_PROTECT(lev);
in = netif->loop_first;
if (in != NULL) {
struct pbuf *in_end = in;
/* Get a packet from the list. With SYS_LIGHTWEIGHT_PROT=1, this is protected */
SYS_ARCH_PROTECT(lev);
while (netif->loop_first != NULL) {
struct pbuf *in, *in_end;
#if LWIP_LOOPBACK_MAX_PBUFS
u8_t clen = 1;
#endif /* LWIP_LOOPBACK_MAX_PBUFS */
while (in_end->len != in_end->tot_len) {
LWIP_ASSERT("bogus pbuf: len != tot_len but next == NULL!", in_end->next != NULL);
in_end = in_end->next;
#if LWIP_LOOPBACK_MAX_PBUFS
clen++;
#endif /* LWIP_LOOPBACK_MAX_PBUFS */
}
#if LWIP_LOOPBACK_MAX_PBUFS
/* adjust the number of pbufs on queue */
LWIP_ASSERT("netif->loop_cnt_current underflow",
((netif->loop_cnt_current - clen) < netif->loop_cnt_current));
netif->loop_cnt_current -= clen;
u8_t clen = 1;
#endif /* LWIP_LOOPBACK_MAX_PBUFS */
/* 'in_end' now points to the last pbuf from 'in' */
if (in_end == netif->loop_last) {
/* this was the last pbuf in the list */
netif->loop_first = netif->loop_last = NULL;
} else {
/* pop the pbuf off the list */
netif->loop_first = in_end->next;
LWIP_ASSERT("should not be null since first != last!", netif->loop_first != NULL);
}
/* De-queue the pbuf from its successors on the 'loop_' list. */
in_end->next = NULL;
in = in_end = netif->loop_first;
while (in_end->len != in_end->tot_len) {
LWIP_ASSERT("bogus pbuf: len != tot_len but next == NULL!", in_end->next != NULL);
in_end = in_end->next;
#if LWIP_LOOPBACK_MAX_PBUFS
clen++;
#endif /* LWIP_LOOPBACK_MAX_PBUFS */
}
#if LWIP_LOOPBACK_MAX_PBUFS
/* adjust the number of pbufs on queue */
LWIP_ASSERT("netif->loop_cnt_current underflow",
((netif->loop_cnt_current - clen) < netif->loop_cnt_current));
netif->loop_cnt_current -= clen;
#endif /* LWIP_LOOPBACK_MAX_PBUFS */
/* 'in_end' now points to the last pbuf from 'in' */
if (in_end == netif->loop_last) {
/* this was the last pbuf in the list */
netif->loop_first = netif->loop_last = NULL;
} else {
/* pop the pbuf off the list */
netif->loop_first = in_end->next;
LWIP_ASSERT("should not be null since first != last!", netif->loop_first != NULL);
}
/* De-queue the pbuf from its successors on the 'loop_' list. */
in_end->next = NULL;
SYS_ARCH_UNPROTECT(lev);
if (in != NULL) {
LINK_STATS_INC(link.recv);
MIB2_STATS_NETIF_ADD(stats_if, ifinoctets, in->tot_len);
MIB2_STATS_NETIF_INC(stats_if, ifinucastpkts);
/* loopback packets are always IP packets! */
if (ip_input(in, netif) != ERR_OK) {
pbuf_free(in);
}
/* Don't reference the packet any more! */
in = NULL;
LINK_STATS_INC(link.recv);
MIB2_STATS_NETIF_ADD(stats_if, ifinoctets, in->tot_len);
MIB2_STATS_NETIF_INC(stats_if, ifinucastpkts);
/* loopback packets are always IP packets! */
if (ip_input(in, netif) != ERR_OK) {
pbuf_free(in);
}
/* go on while there is a packet on the list */
} while (netif->loop_first != NULL);
SYS_ARCH_PROTECT(lev);
}
SYS_ARCH_UNPROTECT(lev);
}
#if !LWIP_NETIF_LOOPBACK_MULTITHREADING