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udhcpc[6]: do not pass xid around, keep it in client_data.xid

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function                                             old     new   delta
perform_release                                      105     169     +64
perform_d6_release                                   259     262      +3
init_d6_packet                                        84      85      +1
send_d6_discover                                     286     285      -1
send_d6_select                                       128     126      -2
send_d6_renew                                        176     174      -2
send_d6_info_request                                  65      63      -2
udhcpc_main                                         2555    2551      -4
send_select                                          130     122      -8
send_renew                                            99      91      -8
send_discover                                         89      81      -8
udhcpc6_main                                        2636    2602     -34
send_release                                          74       -     -74
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 3/9 up/down: 68/-143)           Total: -75 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2021-06-15 01:02:01 +02:00
parent 40a327aeae
commit 827b690fa7
3 changed files with 48 additions and 60 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

56
networking/udhcp/d6_dhcpc.c
View File

@ -479,15 +479,15 @@ static ALWAYS_INLINE uint32_t random_xid(void)
} }
/* Initialize the packet with the proper defaults */ /* Initialize the packet with the proper defaults */
static uint8_t *init_d6_packet(struct d6_packet *packet, char type, uint32_t xid) static uint8_t *init_d6_packet(struct d6_packet *packet, char type)
{ {
uint8_t *ptr; uint8_t *ptr;
unsigned secs; unsigned secs;
memset(packet, 0, sizeof(*packet)); memset(packet, 0, sizeof(*packet));
packet->d6_xid32 = xid; packet->d6_xid32 = client_data.xid;
packet->d6_msg_type = type; packet->d6_msg_type = type; /* union, overwrites lowest byte of d6_xid32 */
/* ELAPSED_TIME option is required to be present by the RFC, /* ELAPSED_TIME option is required to be present by the RFC,
* and some servers do check for its presense. [which?] * and some servers do check for its presense. [which?]
@ -585,13 +585,13 @@ static int d6_mcast_from_client_data_ifindex(struct d6_packet *packet, uint8_t *
* about parameter values the client would like to have returned. * about parameter values the client would like to have returned.
*/ */
/* NOINLINE: limit stack usage in caller */ /* NOINLINE: limit stack usage in caller */
static NOINLINE int send_d6_info_request(uint32_t xid) static NOINLINE int send_d6_info_request(void)
{ {
struct d6_packet packet; struct d6_packet packet;
uint8_t *opt_ptr; uint8_t *opt_ptr;
/* Fill in: msg type */ /* Fill in: msg type, xid, ELAPSED_TIME */
opt_ptr = init_d6_packet(&packet, D6_MSG_INFORMATION_REQUEST, xid); opt_ptr = init_d6_packet(&packet, D6_MSG_INFORMATION_REQUEST);
/* Add options: client-id, /* Add options: client-id,
* "param req" option according to -O, options specified with -x * "param req" option according to -O, options specified with -x
@ -684,14 +684,14 @@ static NOINLINE int send_d6_info_request(uint32_t xid)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/ */
/* NOINLINE: limit stack usage in caller */ /* NOINLINE: limit stack usage in caller */
static NOINLINE int send_d6_discover(uint32_t xid, struct in6_addr *requested_ipv6) static NOINLINE int send_d6_discover(struct in6_addr *requested_ipv6)
{ {
struct d6_packet packet; struct d6_packet packet;
uint8_t *opt_ptr; uint8_t *opt_ptr;
unsigned len; unsigned len;
/* Fill in: msg type */ /* Fill in: msg type, xid, ELAPSED_TIME */
opt_ptr = init_d6_packet(&packet, D6_MSG_SOLICIT, xid); opt_ptr = init_d6_packet(&packet, D6_MSG_SOLICIT);
/* Create new IA_NA, optionally with included IAADDR with requested IP */ /* Create new IA_NA, optionally with included IAADDR with requested IP */
free(client6_data.ia_na); free(client6_data.ia_na);
@ -763,13 +763,13 @@ static NOINLINE int send_d6_discover(uint32_t xid, struct in6_addr *requested_ip
* messages from the server. * messages from the server.
*/ */
/* NOINLINE: limit stack usage in caller */ /* NOINLINE: limit stack usage in caller */
static NOINLINE int send_d6_select(uint32_t xid) static NOINLINE int send_d6_select(void)
{ {
struct d6_packet packet; struct d6_packet packet;
uint8_t *opt_ptr; uint8_t *opt_ptr;
/* Fill in: msg type */ /* Fill in: msg type, xid, ELAPSED_TIME */
opt_ptr = init_d6_packet(&packet, D6_MSG_REQUEST, xid); opt_ptr = init_d6_packet(&packet, D6_MSG_REQUEST);
/* server id */ /* server id */
opt_ptr = mempcpy(opt_ptr, client6_data.server_id, client6_data.server_id->len + 2+2); opt_ptr = mempcpy(opt_ptr, client6_data.server_id, client6_data.server_id->len + 2+2);
@ -836,13 +836,13 @@ static NOINLINE int send_d6_select(uint32_t xid)
* about parameter values the client would like to have returned. * about parameter values the client would like to have returned.
*/ */
/* NOINLINE: limit stack usage in caller */ /* NOINLINE: limit stack usage in caller */
static NOINLINE int send_d6_renew(uint32_t xid, struct in6_addr *server_ipv6, struct in6_addr *our_cur_ipv6) static NOINLINE int send_d6_renew(struct in6_addr *server_ipv6, struct in6_addr *our_cur_ipv6)
{ {
struct d6_packet packet; struct d6_packet packet;
uint8_t *opt_ptr; uint8_t *opt_ptr;
/* Fill in: msg type */ /* Fill in: msg type, xid, ELAPSED_TIME */
opt_ptr = init_d6_packet(&packet, DHCPREQUEST, xid); opt_ptr = init_d6_packet(&packet, DHCPREQUEST);
/* server id */ /* server id */
opt_ptr = mempcpy(opt_ptr, client6_data.server_id, client6_data.server_id->len + 2+2); opt_ptr = mempcpy(opt_ptr, client6_data.server_id, client6_data.server_id->len + 2+2);
@ -877,8 +877,8 @@ int send_d6_release(struct in6_addr *server_ipv6, struct in6_addr *our_cur_ipv6)
uint8_t *opt_ptr; uint8_t *opt_ptr;
struct option_set *ci; struct option_set *ci;
/* Fill in: msg type, client id */ /* Fill in: msg type, xid, ELAPSED_TIME */
opt_ptr = init_d6_packet(&packet, D6_MSG_RELEASE, random_xid()); opt_ptr = init_d6_packet(&packet, D6_MSG_RELEASE);
/* server id */ /* server id */
opt_ptr = mempcpy(opt_ptr, client6_data.server_id, client6_data.server_id->len + 2+2); opt_ptr = mempcpy(opt_ptr, client6_data.server_id, client6_data.server_id->len + 2+2);
/* IA NA (contains our current IP) */ /* IA NA (contains our current IP) */
@ -1097,6 +1097,7 @@ static void perform_d6_release(struct in6_addr *server_ipv6, struct in6_addr *ou
|| client_data.state == RENEW_REQUESTED || client_data.state == RENEW_REQUESTED
) { ) {
bb_simple_info_msg("unicasting a release"); bb_simple_info_msg("unicasting a release");
client_data.xid = random_xid(); //TODO: can omit?
send_d6_release(server_ipv6, our_cur_ipv6); /* unicast */ send_d6_release(server_ipv6, our_cur_ipv6); /* unicast */
} }
bb_simple_info_msg("entering released state"); bb_simple_info_msg("entering released state");
@ -1183,7 +1184,6 @@ int udhcpc6_main(int argc UNUSED_PARAM, char **argv)
struct in6_addr srv6_buf; struct in6_addr srv6_buf;
struct in6_addr ipv6_buf; struct in6_addr ipv6_buf;
struct in6_addr *requested_ipv6; struct in6_addr *requested_ipv6;
uint32_t xid = 0;
int packet_num; int packet_num;
int timeout; /* must be signed */ int timeout; /* must be signed */
int lease_remaining; /* must be signed */ int lease_remaining; /* must be signed */
@ -1387,13 +1387,13 @@ int udhcpc6_main(int argc UNUSED_PARAM, char **argv)
if (!discover_retries || packet_num < discover_retries) { if (!discover_retries || packet_num < discover_retries) {
if (packet_num == 0) { if (packet_num == 0) {
change_listen_mode(LISTEN_RAW); change_listen_mode(LISTEN_RAW);
xid = random_xid(); client_data.xid = random_xid();
} }
/* multicast */ /* multicast */
if (opt & OPT_l) if (opt & OPT_l)
send_d6_info_request(xid); send_d6_info_request();
else else
send_d6_discover(xid, requested_ipv6); send_d6_discover(requested_ipv6);
timeout = discover_timeout; timeout = discover_timeout;
packet_num++; packet_num++;
continue; continue;
@ -1427,7 +1427,7 @@ int udhcpc6_main(int argc UNUSED_PARAM, char **argv)
case REQUESTING: case REQUESTING:
if (!discover_retries || packet_num < discover_retries) { if (!discover_retries || packet_num < discover_retries) {
/* send multicast select packet */ /* send multicast select packet */
send_d6_select(xid); send_d6_select();
timeout = discover_timeout; timeout = discover_timeout;
packet_num++; packet_num++;
continue; continue;
@ -1459,9 +1459,9 @@ int udhcpc6_main(int argc UNUSED_PARAM, char **argv)
* into INIT_SELECTING state. * into INIT_SELECTING state.
*/ */
if (opt & OPT_l) if (opt & OPT_l)
send_d6_info_request(xid); send_d6_info_request();
else else
send_d6_renew(xid, &srv6_buf, requested_ipv6); send_d6_renew(&srv6_buf, requested_ipv6);
timeout = discover_timeout; timeout = discover_timeout;
packet_num++; packet_num++;
continue; continue;
@ -1484,9 +1484,9 @@ int udhcpc6_main(int argc UNUSED_PARAM, char **argv)
* try to find DHCP server using broadcast */ * try to find DHCP server using broadcast */
if (lease_remaining > 0 && packet_num < 3) { if (lease_remaining > 0 && packet_num < 3) {
if (opt & OPT_l) if (opt & OPT_l)
send_d6_info_request(xid); send_d6_info_request();
else /* send a broadcast renew request */ else /* send a broadcast renew request */
send_d6_renew(xid, /*server_ipv6:*/ NULL, requested_ipv6); send_d6_renew(/*server_ipv6:*/ NULL, requested_ipv6);
timeout = discover_timeout; timeout = discover_timeout;
packet_num++; packet_num++;
continue; continue;
@ -1581,9 +1581,9 @@ int udhcpc6_main(int argc UNUSED_PARAM, char **argv)
packet_end = (uint8_t*)&packet + len; packet_end = (uint8_t*)&packet + len;
} }
if ((packet.d6_xid32 & htonl(0x00ffffff)) != xid) { if ((packet.d6_xid32 & htonl(0x00ffffff)) != client_data.xid) {
log1("xid %x (our is %x)%s", log1("xid %x (our is %x)%s",
(unsigned)(packet.d6_xid32 & htonl(0x00ffffff)), (unsigned)xid, (unsigned)(packet.d6_xid32 & htonl(0x00ffffff)), (unsigned)client_data.xid,
", ignoring packet" ", ignoring packet"
); );
continue; continue;

51
networking/udhcp/dhcpc.c
View File

@ -605,7 +605,7 @@ static void init_packet(struct dhcp_packet *packet, char type)
/* Fill in: op, htype, hlen, cookie fields; message type option: */ /* Fill in: op, htype, hlen, cookie fields; message type option: */
udhcp_init_header(packet, type); udhcp_init_header(packet, type);
packet->xid = random_xid(); packet->xid = client_data.xid;
client_data.last_secs = monotonic_sec(); client_data.last_secs = monotonic_sec();
if (client_data.first_secs == 0) if (client_data.first_secs == 0)
@ -719,17 +719,15 @@ static int bcast_or_ucast(struct dhcp_packet *packet, uint32_t ciaddr, uint32_t
/* Broadcast a DHCP discover packet to the network, with an optionally requested IP */ /* Broadcast a DHCP discover packet to the network, with an optionally requested IP */
/* NOINLINE: limit stack usage in caller */ /* NOINLINE: limit stack usage in caller */
static NOINLINE int send_discover(uint32_t xid, uint32_t requested) static NOINLINE int send_discover(uint32_t requested)
{ {
struct dhcp_packet packet; struct dhcp_packet packet;
/* Fill in: op, htype, hlen, cookie, chaddr fields, /* Fill in: op, htype, hlen, cookie, chaddr fields,
* random xid field (we override it below), * xid field, message type option:
* message type option:
*/ */
init_packet(&packet, DHCPDISCOVER); init_packet(&packet, DHCPDISCOVER);
packet.xid = xid;
if (requested) if (requested)
udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested); udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
@ -747,7 +745,7 @@ static NOINLINE int send_discover(uint32_t xid, uint32_t requested)
* "The client _broadcasts_ a DHCPREQUEST message..." * "The client _broadcasts_ a DHCPREQUEST message..."
*/ */
/* NOINLINE: limit stack usage in caller */ /* NOINLINE: limit stack usage in caller */
static NOINLINE int send_select(uint32_t xid, uint32_t server, uint32_t requested) static NOINLINE int send_select(uint32_t server, uint32_t requested)
{ {
struct dhcp_packet packet; struct dhcp_packet packet;
struct in_addr temp_addr; struct in_addr temp_addr;
@ -766,12 +764,10 @@ static NOINLINE int send_select(uint32_t xid, uint32_t server, uint32_t requeste
* include that list in all subsequent messages. * include that list in all subsequent messages.
*/ */
/* Fill in: op, htype, hlen, cookie, chaddr fields, /* Fill in: op, htype, hlen, cookie, chaddr fields,
* random xid field (we override it below), * xid field, message type option:
* message type option:
*/ */
init_packet(&packet, DHCPREQUEST); init_packet(&packet, DHCPREQUEST);
packet.xid = xid;
udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested); udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server); udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
@ -793,7 +789,7 @@ static NOINLINE int send_select(uint32_t xid, uint32_t server, uint32_t requeste
/* Unicast or broadcast a DHCP renew message */ /* Unicast or broadcast a DHCP renew message */
/* NOINLINE: limit stack usage in caller */ /* NOINLINE: limit stack usage in caller */
static NOINLINE int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr) static NOINLINE int send_renew(uint32_t server, uint32_t ciaddr)
{ {
struct dhcp_packet packet; struct dhcp_packet packet;
@ -812,12 +808,10 @@ static NOINLINE int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr)
* replying to the client. * replying to the client.
*/ */
/* Fill in: op, htype, hlen, cookie, chaddr fields, /* Fill in: op, htype, hlen, cookie, chaddr fields,
* random xid field (we override it below), * xid field, message type option:
* message type option:
*/ */
init_packet(&packet, DHCPREQUEST); init_packet(&packet, DHCPREQUEST);
packet.xid = xid;
packet.ciaddr = ciaddr; packet.ciaddr = ciaddr;
/* Add options: maxsize, /* Add options: maxsize,
@ -839,7 +833,7 @@ static NOINLINE int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr)
#if ENABLE_FEATURE_UDHCPC_ARPING #if ENABLE_FEATURE_UDHCPC_ARPING
/* Broadcast a DHCP decline message */ /* Broadcast a DHCP decline message */
/* NOINLINE: limit stack usage in caller */ /* NOINLINE: limit stack usage in caller */
static NOINLINE int send_decline(/*uint32_t xid,*/ uint32_t server, uint32_t requested) static NOINLINE int send_decline(uint32_t server, uint32_t requested)
{ {
struct dhcp_packet packet; struct dhcp_packet packet;
@ -848,14 +842,6 @@ static NOINLINE int send_decline(/*uint32_t xid,*/ uint32_t server, uint32_t req
*/ */
init_packet(&packet, DHCPDECLINE); init_packet(&packet, DHCPDECLINE);
#if 0
/* RFC 2131 says DHCPDECLINE's xid is randomly selected by client,
* but in case the server is buggy and wants DHCPDECLINE's xid
* to match the xid which started entire handshake,
* we use the same xid we used in initial DHCPDISCOVER:
*/
packet.xid = xid;
#endif
/* DHCPDECLINE uses "requested ip", not ciaddr, to store offered IP */ /* DHCPDECLINE uses "requested ip", not ciaddr, to store offered IP */
udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested); udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
@ -1145,6 +1131,7 @@ static void perform_release(uint32_t server_addr, uint32_t requested_ip)
temp_addr.s_addr = requested_ip; temp_addr.s_addr = requested_ip;
bb_info_msg("unicasting a release of %s to %s", bb_info_msg("unicasting a release of %s to %s",
inet_ntoa(temp_addr), buffer); inet_ntoa(temp_addr), buffer);
client_data.xid = random_xid(); //TODO: can omit?
send_release(server_addr, requested_ip); /* unicast */ send_release(server_addr, requested_ip); /* unicast */
} }
bb_simple_info_msg("entering released state"); bb_simple_info_msg("entering released state");
@ -1233,7 +1220,6 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
int discover_retries = 3; int discover_retries = 3;
uint32_t server_addr = server_addr; /* for compiler */ uint32_t server_addr = server_addr; /* for compiler */
uint32_t requested_ip = 0; uint32_t requested_ip = 0;
uint32_t xid = xid; /* for compiler */
int packet_num; int packet_num;
int timeout; /* must be signed */ int timeout; /* must be signed */
int lease_remaining; /* must be signed */ int lease_remaining; /* must be signed */
@ -1458,10 +1444,10 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
if (!discover_retries || packet_num < discover_retries) { if (!discover_retries || packet_num < discover_retries) {
if (packet_num == 0) { if (packet_num == 0) {
change_listen_mode(LISTEN_RAW); change_listen_mode(LISTEN_RAW);
xid = random_xid(); client_data.xid = random_xid();
} }
/* broadcast */ /* broadcast */
send_discover(xid, requested_ip); send_discover(requested_ip);
timeout = discover_timeout; timeout = discover_timeout;
packet_num++; packet_num++;
continue; continue;
@ -1495,7 +1481,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
case REQUESTING: case REQUESTING:
if (packet_num < 3) { if (packet_num < 3) {
/* send broadcast select packet */ /* send broadcast select packet */
send_select(xid, server_addr, requested_ip); send_select(server_addr, requested_ip);
timeout = discover_timeout; timeout = discover_timeout;
packet_num++; packet_num++;
continue; continue;
@ -1526,7 +1512,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
* Anyway, it does recover by eventually failing through * Anyway, it does recover by eventually failing through
* into INIT_SELECTING state. * into INIT_SELECTING state.
*/ */
if (send_renew(xid, server_addr, requested_ip) >= 0) { if (send_renew(server_addr, requested_ip) >= 0) {
timeout = discover_timeout; timeout = discover_timeout;
packet_num++; packet_num++;
continue; continue;
@ -1555,7 +1541,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
* try to find DHCP server using broadcast */ * try to find DHCP server using broadcast */
if (lease_remaining > 0 && packet_num < 3) { if (lease_remaining > 0 && packet_num < 3) {
/* send a broadcast renew request */ /* send a broadcast renew request */
send_renew(xid, 0 /*INADDR_ANY*/, requested_ip); send_renew(0 /*INADDR_ANY*/, requested_ip);
timeout = discover_timeout; timeout = discover_timeout;
packet_num++; packet_num++;
continue; continue;
@ -1648,9 +1634,9 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
continue; continue;
} }
if (packet.xid != xid) { if (packet.xid != client_data.xid) {
log1("xid %x (our is %x)%s", log1("xid %x (our is %x)%s",
(unsigned)packet.xid, (unsigned)xid, (unsigned)packet.xid, (unsigned)client_data.xid,
", ignoring packet" ", ignoring packet"
); );
continue; continue;
@ -1779,7 +1765,8 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
) { ) {
bb_simple_info_msg("offered address is in use " bb_simple_info_msg("offered address is in use "
"(got ARP reply), declining"); "(got ARP reply), declining");
send_decline(/*xid,*/ server_addr, packet.yiaddr); client_data.xid = random_xid(); //TODO: can omit?
send_decline(server_addr, packet.yiaddr);
if (client_data.state != REQUESTING) if (client_data.state != REQUESTING)
d4_run_script_deconfig(); d4_run_script_deconfig();
@ -1814,7 +1801,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
timeout = (unsigned)lease_remaining / 2; timeout = (unsigned)lease_remaining / 2;
client_data.state = BOUND; client_data.state = BOUND;
/* make future renew packets use different xid */ /* make future renew packets use different xid */
/* xid = random_xid(); ...but why bother? */ /* client_data.xid = random_xid(); ...but why bother? */
packet_num = 0; packet_num = 0;
continue; /* back to main loop */ continue; /* back to main loop */
} }

1
networking/udhcp/dhcpc.h
View File

@ -11,6 +11,7 @@ struct client_data_t {
uint8_t client_mac[6]; /* Our mac address */ uint8_t client_mac[6]; /* Our mac address */
IF_FEATURE_UDHCP_PORT(uint16_t port;) IF_FEATURE_UDHCP_PORT(uint16_t port;)
int ifindex; /* Index number of the interface to use */ int ifindex; /* Index number of the interface to use */
uint32_t xid;
uint8_t opt_mask[256 / 8]; /* Bitmask of options to send (-O option) */ uint8_t opt_mask[256 / 8]; /* Bitmask of options to send (-O option) */
// ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ TODO: DHCPv6 has 16-bit option numbers // ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ TODO: DHCPv6 has 16-bit option numbers
const char *interface; /* The name of the interface to use */ const char *interface; /* The name of the interface to use */