| Message ID | 1462218931-4573-4-git-send-email-thuth@redhat.com |
|---|---|
| State | Accepted |
| Headers | show |
On Mon, May 02, 2016 at 09:55:29PM +0200, Thomas Huth wrote: > The set_ipv6_address() function calls ip6_create_ll_address() to > get a link-local address. The latter function uses malloc to create > a buffer for composing that address, and returns the corresponding > poniter to the caller. However, set_ipv6_address() does not free > that buffer again, so the allocated memory is lost. > Since set_ipv6_address() already allocated space for the new IPv6 > address anyway, let's fix this issue by passing the buffer from > set_ipv6_address() to ip6_create_ll_address() instead, so that > ip6_create_ll_address() does not have to allocate memory at all. > > Signed-off-by: Thomas Huth <thuth@redhat.com> > --- > clients/net-snk/app/netlib/ipv6.c | 18 +++++------------- > clients/net-snk/app/netlib/ipv6.h | 2 +- > 2 files changed, 6 insertions(+), 14 deletions(-) We could probably just get rid of ip6_create_ll_address, opencoding the two-liner at its single callsite. Anyway, Reviewed-by: Andrew Jones <drjones@redhat.com> > > diff --git a/clients/net-snk/app/netlib/ipv6.c b/clients/net-snk/app/netlib/ipv6.c > index baa5034..220fd36 100644 > --- a/clients/net-snk/app/netlib/ipv6.c > +++ b/clients/net-snk/app/netlib/ipv6.c > @@ -77,9 +77,7 @@ void set_ipv6_address(int fd, ip6_addr_t *_own_ip6) > /* If no address was passed as a parameter generate a link-local > * address from our MAC address.*/ > if (_own_ip6 == NULL) > - memcpy(&(own_ip6->addr.addr), > - ip6_create_ll_address(get_mac_address()), > - IPV6_ADDR_LENGTH); > + ip6_create_ll_address(get_mac_address(), &own_ip6->addr); > else > memcpy (&(own_ip6->addr.addr), _own_ip6, 16); > > @@ -225,18 +223,12 @@ uint64_t mac2eui64(const uint8_t *mac) > * NET: create link-local IPv6 address > * > * @param own_mac MAC of NIC > - * @return ll_addr pointer to newly created link-local address > + * @param ll_addr pointer to link-local address which should be created > */ > -ip6_addr_t *ip6_create_ll_address(const uint8_t *own_mac) > +void ip6_create_ll_address(const uint8_t *own_mac, ip6_addr_t *ll_addr) > { > - ip6_addr_t *ll_addr; > - > - ll_addr = malloc (sizeof (struct ip6addr_list_entry)); > - memset (ll_addr, 0, IPV6_ADDR_LENGTH); > - ll_addr->part.prefix |= IPV6_LL_PREFIX; > - ll_addr->part.interface_id |= mac2eui64((uint8_t *) own_mac); > - > - return ll_addr; > + ll_addr->part.prefix = IPV6_LL_PREFIX; > + ll_addr->part.interface_id = mac2eui64((uint8_t *) own_mac); > } > > /* > diff --git a/clients/net-snk/app/netlib/ipv6.h b/clients/net-snk/app/netlib/ipv6.h > index 72c6ee2..6565a88 100644 > --- a/clients/net-snk/app/netlib/ipv6.h > +++ b/clients/net-snk/app/netlib/ipv6.h > @@ -150,7 +150,7 @@ void set_ipv6_address(int fd, ip6_addr_t *own_ip6); > ip6_addr_t *get_ipv6_address(void); > > /* Create link-local address from a given Mac Address */ > -ip6_addr_t * ip6_create_ll_address (const uint8_t *own_mac); > +void ip6_create_ll_address (const uint8_t *own_mac, ip6_addr_t *ll_addr); > > /* For a given MAC calculates EUI64-Identifier.*/ > uint64_t mac2eui64 (const uint8_t *mac); > -- > 1.8.3.1 >
diff --git a/clients/net-snk/app/netlib/ipv6.c b/clients/net-snk/app/netlib/ipv6.c index baa5034..220fd36 100644 --- a/clients/net-snk/app/netlib/ipv6.c +++ b/clients/net-snk/app/netlib/ipv6.c @@ -77,9 +77,7 @@ void set_ipv6_address(int fd, ip6_addr_t *_own_ip6) /* If no address was passed as a parameter generate a link-local * address from our MAC address.*/ if (_own_ip6 == NULL) - memcpy(&(own_ip6->addr.addr), - ip6_create_ll_address(get_mac_address()), - IPV6_ADDR_LENGTH); + ip6_create_ll_address(get_mac_address(), &own_ip6->addr); else memcpy (&(own_ip6->addr.addr), _own_ip6, 16); @@ -225,18 +223,12 @@ uint64_t mac2eui64(const uint8_t *mac) * NET: create link-local IPv6 address * * @param own_mac MAC of NIC - * @return ll_addr pointer to newly created link-local address + * @param ll_addr pointer to link-local address which should be created */ -ip6_addr_t *ip6_create_ll_address(const uint8_t *own_mac) +void ip6_create_ll_address(const uint8_t *own_mac, ip6_addr_t *ll_addr) { - ip6_addr_t *ll_addr; - - ll_addr = malloc (sizeof (struct ip6addr_list_entry)); - memset (ll_addr, 0, IPV6_ADDR_LENGTH); - ll_addr->part.prefix |= IPV6_LL_PREFIX; - ll_addr->part.interface_id |= mac2eui64((uint8_t *) own_mac); - - return ll_addr; + ll_addr->part.prefix = IPV6_LL_PREFIX; + ll_addr->part.interface_id = mac2eui64((uint8_t *) own_mac); } /* diff --git a/clients/net-snk/app/netlib/ipv6.h b/clients/net-snk/app/netlib/ipv6.h index 72c6ee2..6565a88 100644 --- a/clients/net-snk/app/netlib/ipv6.h +++ b/clients/net-snk/app/netlib/ipv6.h @@ -150,7 +150,7 @@ void set_ipv6_address(int fd, ip6_addr_t *own_ip6); ip6_addr_t *get_ipv6_address(void); /* Create link-local address from a given Mac Address */ -ip6_addr_t * ip6_create_ll_address (const uint8_t *own_mac); +void ip6_create_ll_address (const uint8_t *own_mac, ip6_addr_t *ll_addr); /* For a given MAC calculates EUI64-Identifier.*/ uint64_t mac2eui64 (const uint8_t *mac);
The set_ipv6_address() function calls ip6_create_ll_address() to get a link-local address. The latter function uses malloc to create a buffer for composing that address, and returns the corresponding poniter to the caller. However, set_ipv6_address() does not free that buffer again, so the allocated memory is lost. Since set_ipv6_address() already allocated space for the new IPv6 address anyway, let's fix this issue by passing the buffer from set_ipv6_address() to ip6_create_ll_address() instead, so that ip6_create_ll_address() does not have to allocate memory at all. Signed-off-by: Thomas Huth <thuth@redhat.com> --- clients/net-snk/app/netlib/ipv6.c | 18 +++++------------- clients/net-snk/app/netlib/ipv6.h | 2 +- 2 files changed, 6 insertions(+), 14 deletions(-)