net/dhcp: Replace parse_dhcp_vendor() with find_dhcp_option()
For proper DHCP support we will need to parse DHCP options from a packet more often and at various places. Refactor the option parsing into a new function, which will scan a packet to find *a particular* option field. Use that new function in places where we were dealing with DHCP options before. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This commit is contained in:
Andrei Borzenkov
Daniel Kiper
parent
0b5c14c7f6
commit
4c44bbd835
1 changed files with 119 additions and 112 deletions
|
|
@ -25,25 +25,41 @@
|
|||
#include <grub/net/udp.h>
|
||||
#include <grub/datetime.h>
|
||||
|
||||
static void
|
||||
parse_dhcp_vendor (const char *name, const void *vend, int limit, int *mask)
|
||||
static const void *
|
||||
find_dhcp_option (const struct grub_net_bootp_packet *bp, grub_size_t size,
|
||||
grub_uint8_t opt_code, grub_uint8_t *opt_len)
|
||||
{
|
||||
const grub_uint8_t *ptr, *ptr0;
|
||||
const grub_uint8_t *ptr;
|
||||
grub_size_t i;
|
||||
|
||||
ptr = ptr0 = vend;
|
||||
if (opt_len)
|
||||
*opt_len = 0;
|
||||
|
||||
/* Is the packet big enough to hold at least the magic cookie? */
|
||||
if (size < sizeof (*bp) + sizeof (grub_uint32_t))
|
||||
return NULL;
|
||||
|
||||
/*
|
||||
* Pointer arithmetic to point behind the common stub packet, where
|
||||
* the options start.
|
||||
*/
|
||||
ptr = (grub_uint8_t *) (bp + 1);
|
||||
|
||||
if (ptr[0] != GRUB_NET_BOOTP_RFC1048_MAGIC_0
|
||||
|| ptr[1] != GRUB_NET_BOOTP_RFC1048_MAGIC_1
|
||||
|| ptr[2] != GRUB_NET_BOOTP_RFC1048_MAGIC_2
|
||||
|| ptr[3] != GRUB_NET_BOOTP_RFC1048_MAGIC_3)
|
||||
return;
|
||||
ptr = ptr + sizeof (grub_uint32_t);
|
||||
while (ptr - ptr0 < limit)
|
||||
return NULL;
|
||||
|
||||
size -= sizeof (*bp);
|
||||
i = sizeof (grub_uint32_t);
|
||||
|
||||
while (i < size)
|
||||
{
|
||||
grub_uint8_t tagtype;
|
||||
grub_uint8_t taglength;
|
||||
|
||||
tagtype = *ptr++;
|
||||
tagtype = ptr[i++];
|
||||
|
||||
/* Pad tag. */
|
||||
if (tagtype == GRUB_NET_BOOTP_PAD)
|
||||
|
|
@ -51,81 +67,27 @@ parse_dhcp_vendor (const char *name, const void *vend, int limit, int *mask)
|
|||
|
||||
/* End tag. */
|
||||
if (tagtype == GRUB_NET_BOOTP_END)
|
||||
return;
|
||||
break;
|
||||
|
||||
taglength = *ptr++;
|
||||
if (i >= size)
|
||||
return NULL;
|
||||
|
||||
switch (tagtype)
|
||||
taglength = ptr[i++];
|
||||
if (i + taglength >= size)
|
||||
return NULL;
|
||||
|
||||
/* FIXME RFC 3396 options concatentation */
|
||||
if (tagtype == opt_code)
|
||||
{
|
||||
case GRUB_NET_BOOTP_NETMASK:
|
||||
if (taglength == 4)
|
||||
{
|
||||
int i;
|
||||
for (i = 0; i < 32; i++)
|
||||
if (!(ptr[i / 8] & (1 << (7 - (i % 8)))))
|
||||
break;
|
||||
*mask = i;
|
||||
}
|
||||
break;
|
||||
|
||||
case GRUB_NET_BOOTP_ROUTER:
|
||||
if (taglength == 4)
|
||||
{
|
||||
grub_net_network_level_netaddress_t target;
|
||||
grub_net_network_level_address_t gw;
|
||||
char *rname;
|
||||
|
||||
target.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
|
||||
target.ipv4.base = 0;
|
||||
target.ipv4.masksize = 0;
|
||||
gw.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
|
||||
grub_memcpy (&gw.ipv4, ptr, sizeof (gw.ipv4));
|
||||
rname = grub_xasprintf ("%s:default", name);
|
||||
if (rname)
|
||||
grub_net_add_route_gw (rname, target, gw, NULL);
|
||||
grub_free (rname);
|
||||
}
|
||||
break;
|
||||
case GRUB_NET_BOOTP_DNS:
|
||||
{
|
||||
int i;
|
||||
for (i = 0; i < taglength / 4; i++)
|
||||
{
|
||||
struct grub_net_network_level_address s;
|
||||
s.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
|
||||
s.ipv4 = grub_get_unaligned32 (ptr);
|
||||
s.option = DNS_OPTION_PREFER_IPV4;
|
||||
grub_net_add_dns_server (&s);
|
||||
ptr += 4;
|
||||
}
|
||||
}
|
||||
continue;
|
||||
case GRUB_NET_BOOTP_HOSTNAME:
|
||||
grub_env_set_net_property (name, "hostname", (const char *) ptr,
|
||||
taglength);
|
||||
break;
|
||||
|
||||
case GRUB_NET_BOOTP_DOMAIN:
|
||||
grub_env_set_net_property (name, "domain", (const char *) ptr,
|
||||
taglength);
|
||||
break;
|
||||
|
||||
case GRUB_NET_BOOTP_ROOT_PATH:
|
||||
grub_env_set_net_property (name, "rootpath", (const char *) ptr,
|
||||
taglength);
|
||||
break;
|
||||
|
||||
case GRUB_NET_BOOTP_EXTENSIONS_PATH:
|
||||
grub_env_set_net_property (name, "extensionspath", (const char *) ptr,
|
||||
taglength);
|
||||
break;
|
||||
|
||||
/* If you need any other options please contact GRUB
|
||||
development team. */
|
||||
if (opt_len)
|
||||
*opt_len = taglength;
|
||||
return &ptr[i];
|
||||
}
|
||||
|
||||
ptr += taglength;
|
||||
i += taglength;
|
||||
}
|
||||
|
||||
return NULL;
|
||||
}
|
||||
|
||||
#define OFFSET_OF(x, y) ((grub_size_t)((grub_uint8_t *)((y)->x) - (grub_uint8_t *)(y)))
|
||||
|
|
@ -143,6 +105,8 @@ grub_net_configure_by_dhcp_ack (const char *name,
|
|||
struct grub_net_network_level_interface *inter;
|
||||
int mask = -1;
|
||||
char server_ip[sizeof ("xxx.xxx.xxx.xxx")];
|
||||
const grub_uint8_t *opt;
|
||||
grub_uint8_t opt_len;
|
||||
|
||||
addr.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
|
||||
addr.ipv4 = bp->your_ip;
|
||||
|
|
@ -225,10 +189,70 @@ grub_net_configure_by_dhcp_ack (const char *name,
|
|||
**path = 0;
|
||||
}
|
||||
}
|
||||
if (size > OFFSET_OF (vendor, bp))
|
||||
parse_dhcp_vendor (name, &bp->vendor, size - OFFSET_OF (vendor, bp), &mask);
|
||||
|
||||
opt = find_dhcp_option (bp, size, GRUB_NET_BOOTP_NETMASK, &opt_len);
|
||||
if (opt && opt_len == 4)
|
||||
{
|
||||
int i;
|
||||
for (i = 0; i < 32; i++)
|
||||
if (!(opt[i / 8] & (1 << (7 - (i % 8)))))
|
||||
break;
|
||||
mask = i;
|
||||
}
|
||||
grub_net_add_ipv4_local (inter, mask);
|
||||
|
||||
/* We do not implement dead gateway detection and the first entry SHOULD
|
||||
be preferred one */
|
||||
opt = find_dhcp_option (bp, size, GRUB_NET_BOOTP_ROUTER, &opt_len);
|
||||
if (opt && opt_len && !(opt_len & 3))
|
||||
{
|
||||
grub_net_network_level_netaddress_t target;
|
||||
grub_net_network_level_address_t gw;
|
||||
char *rname;
|
||||
|
||||
target.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
|
||||
target.ipv4.base = 0;
|
||||
target.ipv4.masksize = 0;
|
||||
gw.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
|
||||
gw.ipv4 = grub_get_unaligned32 (opt);
|
||||
rname = grub_xasprintf ("%s:default", name);
|
||||
if (rname)
|
||||
grub_net_add_route_gw (rname, target, gw, 0);
|
||||
grub_free (rname);
|
||||
}
|
||||
|
||||
opt = find_dhcp_option (bp, size, GRUB_NET_BOOTP_DNS, &opt_len);
|
||||
if (opt && opt_len && !(opt_len & 3))
|
||||
{
|
||||
int i;
|
||||
for (i = 0; i < opt_len / 4; i++)
|
||||
{
|
||||
struct grub_net_network_level_address s;
|
||||
|
||||
s.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
|
||||
s.ipv4 = grub_get_unaligned32 (opt);
|
||||
s.option = DNS_OPTION_PREFER_IPV4;
|
||||
grub_net_add_dns_server (&s);
|
||||
opt += 4;
|
||||
}
|
||||
}
|
||||
|
||||
opt = find_dhcp_option (bp, size, GRUB_NET_BOOTP_HOSTNAME, &opt_len);
|
||||
if (opt && opt_len)
|
||||
grub_env_set_net_property (name, "hostname", (const char *) opt, opt_len);
|
||||
|
||||
opt = find_dhcp_option (bp, size, GRUB_NET_BOOTP_DOMAIN, &opt_len);
|
||||
if (opt && opt_len)
|
||||
grub_env_set_net_property (name, "domain", (const char *) opt, opt_len);
|
||||
|
||||
opt = find_dhcp_option (bp, size, GRUB_NET_BOOTP_ROOT_PATH, &opt_len);
|
||||
if (opt && opt_len)
|
||||
grub_env_set_net_property (name, "rootpath", (const char *) opt, opt_len);
|
||||
|
||||
opt = find_dhcp_option (bp, size, GRUB_NET_BOOTP_EXTENSIONS_PATH, &opt_len);
|
||||
if (opt && opt_len)
|
||||
grub_env_set_net_property (name, "extensionspath", (const char *) opt, opt_len);
|
||||
|
||||
inter->dhcp_ack = grub_malloc (size);
|
||||
if (inter->dhcp_ack)
|
||||
{
|
||||
|
|
@ -286,8 +310,8 @@ grub_cmd_dhcpopt (struct grub_command *cmd __attribute__ ((unused)),
|
|||
int argc, char **args)
|
||||
{
|
||||
struct grub_net_network_level_interface *inter;
|
||||
int num;
|
||||
grub_uint8_t *ptr;
|
||||
unsigned num;
|
||||
const grub_uint8_t *ptr;
|
||||
grub_uint8_t taglength;
|
||||
|
||||
if (argc < 4)
|
||||
|
|
@ -305,44 +329,27 @@ grub_cmd_dhcpopt (struct grub_command *cmd __attribute__ ((unused)),
|
|||
if (!inter->dhcp_ack)
|
||||
return grub_error (GRUB_ERR_IO, N_("no DHCP info found"));
|
||||
|
||||
if (inter->dhcp_acklen <= OFFSET_OF (vendor, inter->dhcp_ack))
|
||||
ptr = inter->dhcp_ack->vendor;
|
||||
|
||||
/* This duplicates check in find_dhcp_option to preserve previous error return */
|
||||
if (inter->dhcp_acklen < OFFSET_OF (vendor, inter->dhcp_ack) + sizeof (grub_uint32_t)
|
||||
|| ptr[0] != GRUB_NET_BOOTP_RFC1048_MAGIC_0
|
||||
|| ptr[1] != GRUB_NET_BOOTP_RFC1048_MAGIC_1
|
||||
|| ptr[2] != GRUB_NET_BOOTP_RFC1048_MAGIC_2
|
||||
|| ptr[3] != GRUB_NET_BOOTP_RFC1048_MAGIC_3)
|
||||
return grub_error (GRUB_ERR_IO, N_("no DHCP options found"));
|
||||
|
||||
num = grub_strtoul (args[2], 0, 0);
|
||||
if (grub_errno)
|
||||
return grub_errno;
|
||||
|
||||
ptr = inter->dhcp_ack->vendor;
|
||||
/* Exclude PAD (0) and END (255) option codes */
|
||||
if (num == 0 || num > 254)
|
||||
return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("invalid DHCP option code"));
|
||||
|
||||
if (ptr[0] != GRUB_NET_BOOTP_RFC1048_MAGIC_0
|
||||
|| ptr[1] != GRUB_NET_BOOTP_RFC1048_MAGIC_1
|
||||
|| ptr[2] != GRUB_NET_BOOTP_RFC1048_MAGIC_2
|
||||
|| ptr[3] != GRUB_NET_BOOTP_RFC1048_MAGIC_3)
|
||||
return grub_error (GRUB_ERR_IO, N_("no DHCP options found"));
|
||||
ptr = ptr + sizeof (grub_uint32_t);
|
||||
while (1)
|
||||
{
|
||||
grub_uint8_t tagtype;
|
||||
|
||||
if (ptr >= ((grub_uint8_t *) inter->dhcp_ack) + inter->dhcp_acklen)
|
||||
return grub_error (GRUB_ERR_IO, N_("no DHCP option %d found"), num);
|
||||
|
||||
tagtype = *ptr++;
|
||||
|
||||
/* Pad tag. */
|
||||
if (tagtype == 0)
|
||||
continue;
|
||||
|
||||
/* End tag. */
|
||||
if (tagtype == 0xff)
|
||||
return grub_error (GRUB_ERR_IO, N_("no DHCP option %d found"), num);
|
||||
|
||||
taglength = *ptr++;
|
||||
|
||||
if (tagtype == num)
|
||||
break;
|
||||
ptr += taglength;
|
||||
}
|
||||
ptr = find_dhcp_option (inter->dhcp_ack, inter->dhcp_acklen, num, &taglength);
|
||||
if (!ptr)
|
||||
return grub_error (GRUB_ERR_IO, N_("no DHCP option %u found"), num);
|
||||
|
||||
if (grub_strcmp (args[3], "string") == 0)
|
||||
{
|
||||
|
|
|
|||
Loading…
Reference in a new issue