[git commit] dhcp: merge leases.c and static_leases.c into dhcpd.c
Denys Vlasenko
vda.linux at googlemail.com
Mon Oct 3 22:56:58 UTC 2016
commit: https://git.busybox.net/busybox/commit/?id=a85740c8afe6942beff90fec345403b37b2a9092
branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master
function old new delta
send_offer 292 461 +169
udhcpd_main 1531 1588 +57
read_leases 330 332 +2
add_lease 314 312 -2
find_lease_by_mac 68 - -68
find_free_or_expired_nip 174 - -174
------------------------------------------------------------------------------
(add/remove: 0/4 grow/shrink: 3/1 up/down: 228/-244) Total: -16 bytes
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
networking/udhcp/Kbuild.src | 2 +-
networking/udhcp/arpping.c | 1 -
networking/udhcp/dhcpd.c | 222 ++++++++++++++++++++++++++++++++++++++-
networking/udhcp/dhcpd.h | 14 ---
networking/udhcp/leases.c | 211 -------------------------------------
networking/udhcp/static_leases.c | 22 ----
6 files changed, 219 insertions(+), 253 deletions(-)
diff --git a/networking/udhcp/Kbuild.src b/networking/udhcp/Kbuild.src
index bfa7768..5ea77df 100644
--- a/networking/udhcp/Kbuild.src
+++ b/networking/udhcp/Kbuild.src
@@ -13,7 +13,7 @@ lib-$(CONFIG_UDHCPC) += common.o packet.o signalpipe.o socket.o
lib-$(CONFIG_UDHCPD) += common.o packet.o signalpipe.o socket.o
lib-$(CONFIG_UDHCPC) += dhcpc.o
-lib-$(CONFIG_UDHCPD) += dhcpd.o arpping.o leases.o static_leases.o
+lib-$(CONFIG_UDHCPD) += dhcpd.o arpping.o
lib-$(CONFIG_DUMPLEASES) += dumpleases.o
lib-$(CONFIG_DHCPRELAY) += dhcprelay.o
diff --git a/networking/udhcp/arpping.c b/networking/udhcp/arpping.c
index c980273..215d023 100644
--- a/networking/udhcp/arpping.c
+++ b/networking/udhcp/arpping.c
@@ -9,7 +9,6 @@
#include <net/if_arp.h>
#include "common.h"
-#include "dhcpd.h"
struct arpMsg {
/* Ethernet header */
diff --git a/networking/udhcp/dhcpd.c b/networking/udhcp/dhcpd.c
index b625756..56116d0 100644
--- a/networking/udhcp/dhcpd.c
+++ b/networking/udhcp/dhcpd.c
@@ -39,6 +39,10 @@
#include "dhcpc.h"
#include "dhcpd.h"
+/* globals */
+struct dyn_lease *g_leases;
+/* struct server_config_t server_config is in bb_common_bufsiz1 */
+
/* Takes the address of the pointer to the static_leases linked list,
* address to a 6 byte mac address,
* 4 byte IP address */
@@ -72,6 +76,17 @@ static uint32_t get_static_nip_by_mac(struct static_lease *st_lease, void *mac)
return 0;
}
+static int is_nip_reserved(struct static_lease *st_lease, uint32_t nip)
+{
+ while (st_lease) {
+ if (st_lease->nip == nip)
+ return 1;
+ st_lease = st_lease->next;
+ }
+
+ return 0;
+}
+
#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 2
/* Print out static leases just to check what's going on */
/* Takes the address of the pointer to the static_leases linked list */
@@ -96,6 +111,209 @@ static void log_static_leases(struct static_lease **st_lease_pp)
# define log_static_leases(st_lease_pp) ((void)0)
#endif
+/* Find the oldest expired lease, NULL if there are no expired leases */
+static struct dyn_lease *oldest_expired_lease(void)
+{
+ struct dyn_lease *oldest_lease = NULL;
+ leasetime_t oldest_time = time(NULL);
+ unsigned i;
+
+ /* Unexpired leases have g_leases[i].expires >= current time
+ * and therefore can't ever match */
+ for (i = 0; i < server_config.max_leases; i++) {
+ if (g_leases[i].expires == 0 /* empty entry */
+ || g_leases[i].expires < oldest_time
+ ) {
+ oldest_time = g_leases[i].expires;
+ oldest_lease = &g_leases[i];
+ }
+ }
+ return oldest_lease;
+}
+
+/* Clear out all leases with matching nonzero chaddr OR yiaddr.
+ * If chaddr == NULL, this is a conflict lease.
+ */
+static void clear_leases(const uint8_t *chaddr, uint32_t yiaddr)
+{
+ unsigned i;
+
+ for (i = 0; i < server_config.max_leases; i++) {
+ if ((chaddr && memcmp(g_leases[i].lease_mac, chaddr, 6) == 0)
+ || (yiaddr && g_leases[i].lease_nip == yiaddr)
+ ) {
+ memset(&g_leases[i], 0, sizeof(g_leases[i]));
+ }
+ }
+}
+
+/* Add a lease into the table, clearing out any old ones.
+ * If chaddr == NULL, this is a conflict lease.
+ */
+static struct dyn_lease *add_lease(
+ const uint8_t *chaddr, uint32_t yiaddr,
+ leasetime_t leasetime,
+ const char *hostname, int hostname_len)
+{
+ struct dyn_lease *oldest;
+
+ /* clean out any old ones */
+ clear_leases(chaddr, yiaddr);
+
+ oldest = oldest_expired_lease();
+
+ if (oldest) {
+ memset(oldest, 0, sizeof(*oldest));
+ if (hostname) {
+ char *p;
+
+ hostname_len++; /* include NUL */
+ if (hostname_len > sizeof(oldest->hostname))
+ hostname_len = sizeof(oldest->hostname);
+ p = safe_strncpy(oldest->hostname, hostname, hostname_len);
+ /*
+ * Sanitization (s/bad_char/./g).
+ * The intent is not to allow only "DNS-valid" hostnames,
+ * but merely make dumpleases output safe for shells to use.
+ * We accept "0-9A-Za-z._-", all other chars turn to dots.
+ */
+ while (*p) {
+ if (!isalnum(*p) && *p != '-' && *p != '_')
+ *p = '.';
+ p++;
+ }
+ }
+ if (chaddr)
+ memcpy(oldest->lease_mac, chaddr, 6);
+ oldest->lease_nip = yiaddr;
+ oldest->expires = time(NULL) + leasetime;
+ }
+
+ return oldest;
+}
+
+/* True if a lease has expired */
+static int is_expired_lease(struct dyn_lease *lease)
+{
+ return (lease->expires < (leasetime_t) time(NULL));
+}
+
+/* Find the first lease that matches MAC, NULL if no match */
+static struct dyn_lease *find_lease_by_mac(const uint8_t *mac)
+{
+ unsigned i;
+
+ for (i = 0; i < server_config.max_leases; i++)
+ if (memcmp(g_leases[i].lease_mac, mac, 6) == 0)
+ return &g_leases[i];
+
+ return NULL;
+}
+
+/* Find the first lease that matches IP, NULL is no match */
+static struct dyn_lease *find_lease_by_nip(uint32_t nip)
+{
+ unsigned i;
+
+ for (i = 0; i < server_config.max_leases; i++)
+ if (g_leases[i].lease_nip == nip)
+ return &g_leases[i];
+
+ return NULL;
+}
+
+/* Check if the IP is taken; if it is, add it to the lease table */
+static int nobody_responds_to_arp(uint32_t nip, const uint8_t *safe_mac, unsigned arpping_ms)
+{
+ struct in_addr temp;
+ int r;
+
+ r = arpping(nip, safe_mac,
+ server_config.server_nip,
+ server_config.server_mac,
+ server_config.interface,
+ arpping_ms);
+ if (r)
+ return r;
+
+ temp.s_addr = nip;
+ bb_error_msg("%s belongs to someone, reserving it for %u seconds",
+ inet_ntoa(temp), (unsigned)server_config.conflict_time);
+ add_lease(NULL, nip, server_config.conflict_time, NULL, 0);
+ return 0;
+}
+
+/* Find a new usable (we think) address */
+static uint32_t find_free_or_expired_nip(const uint8_t *safe_mac, unsigned arpping_ms)
+{
+ uint32_t addr;
+ struct dyn_lease *oldest_lease = NULL;
+
+#if ENABLE_FEATURE_UDHCPD_BASE_IP_ON_MAC
+ uint32_t stop;
+ unsigned i, hash;
+
+ /* hash hwaddr: use the SDBM hashing algorithm. Seems to give good
+ * dispersal even with similarly-valued "strings".
+ */
+ hash = 0;
+ for (i = 0; i < 6; i++)
+ hash += safe_mac[i] + (hash << 6) + (hash << 16) - hash;
+
+ /* pick a seed based on hwaddr then iterate until we find a free address. */
+ addr = server_config.start_ip
+ + (hash % (1 + server_config.end_ip - server_config.start_ip));
+ stop = addr;
+#else
+ addr = server_config.start_ip;
+#define stop (server_config.end_ip + 1)
+#endif
+ do {
+ uint32_t nip;
+ struct dyn_lease *lease;
+
+ /* ie, 192.168.55.0 */
+ if ((addr & 0xff) == 0)
+ goto next_addr;
+ /* ie, 192.168.55.255 */
+ if ((addr & 0xff) == 0xff)
+ goto next_addr;
+ nip = htonl(addr);
+ /* skip our own address */
+ if (nip == server_config.server_nip)
+ goto next_addr;
+ /* is this a static lease addr? */
+ if (is_nip_reserved(server_config.static_leases, nip))
+ goto next_addr;
+
+ lease = find_lease_by_nip(nip);
+ if (!lease) {
+//TODO: DHCP servers do not always sit on the same subnet as clients: should *ping*, not arp-ping!
+ if (nobody_responds_to_arp(nip, safe_mac, arpping_ms))
+ return nip;
+ } else {
+ if (!oldest_lease || lease->expires < oldest_lease->expires)
+ oldest_lease = lease;
+ }
+
+ next_addr:
+ addr++;
+#if ENABLE_FEATURE_UDHCPD_BASE_IP_ON_MAC
+ if (addr > server_config.end_ip)
+ addr = server_config.start_ip;
+#endif
+ } while (addr != stop);
+
+ if (oldest_lease
+ && is_expired_lease(oldest_lease)
+ && nobody_responds_to_arp(oldest_lease->lease_nip, safe_mac, arpping_ms)
+ ) {
+ return oldest_lease->lease_nip;
+ }
+
+ return 0;
+}
+
/* On these functions, make sure your datatype matches */
static int FAST_FUNC read_str(const char *line, void *arg)
{
@@ -568,10 +786,6 @@ static NOINLINE void send_inform(struct dhcp_packet *oldpacket)
send_packet(&packet, /*force_bcast:*/ 0);
}
-/* globals */
-struct dyn_lease *g_leases;
-/* struct server_config_t server_config is in bb_common_bufsiz1 */
-
int udhcpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int udhcpd_main(int argc UNUSED_PARAM, char **argv)
{
diff --git a/networking/udhcp/dhcpd.h b/networking/udhcp/dhcpd.h
index b8d94a7..b8f96b0 100644
--- a/networking/udhcp/dhcpd.h
+++ b/networking/udhcp/dhcpd.h
@@ -90,20 +90,6 @@ struct dyn_lease {
/* total size is a multiply of 4 */
} PACKED;
-extern struct dyn_lease *g_leases;
-
-struct dyn_lease *add_lease(
- const uint8_t *chaddr, uint32_t yiaddr,
- leasetime_t leasetime,
- const char *hostname, int hostname_len
- ) FAST_FUNC;
-int is_expired_lease(struct dyn_lease *lease) FAST_FUNC;
-struct dyn_lease *find_lease_by_mac(const uint8_t *mac) FAST_FUNC;
-struct dyn_lease *find_lease_by_nip(uint32_t nip) FAST_FUNC;
-uint32_t find_free_or_expired_nip(const uint8_t *safe_mac, unsigned arpping_ms) FAST_FUNC;
-
-int is_nip_reserved(struct static_lease *st_lease, uint32_t nip) FAST_FUNC;
-
POP_SAVED_FUNCTION_VISIBILITY
#endif
diff --git a/networking/udhcp/leases.c b/networking/udhcp/leases.c
deleted file mode 100644
index 6642e39..0000000
--- a/networking/udhcp/leases.c
+++ /dev/null
@@ -1,211 +0,0 @@
-/* vi: set sw=4 ts=4: */
-/*
- * Russ Dill <Russ.Dill at asu.edu> July 2001
- *
- * Licensed under GPLv2, see file LICENSE in this source tree.
- */
-#include "common.h"
-#include "dhcpd.h"
-
-/* Find the oldest expired lease, NULL if there are no expired leases */
-static struct dyn_lease *oldest_expired_lease(void)
-{
- struct dyn_lease *oldest_lease = NULL;
- leasetime_t oldest_time = time(NULL);
- unsigned i;
-
- /* Unexpired leases have g_leases[i].expires >= current time
- * and therefore can't ever match */
- for (i = 0; i < server_config.max_leases; i++) {
- if (g_leases[i].expires == 0 /* empty entry */
- || g_leases[i].expires < oldest_time
- ) {
- oldest_time = g_leases[i].expires;
- oldest_lease = &g_leases[i];
- }
- }
- return oldest_lease;
-}
-
-/* Clear out all leases with matching nonzero chaddr OR yiaddr.
- * If chaddr == NULL, this is a conflict lease.
- */
-static void clear_leases(const uint8_t *chaddr, uint32_t yiaddr)
-{
- unsigned i;
-
- for (i = 0; i < server_config.max_leases; i++) {
- if ((chaddr && memcmp(g_leases[i].lease_mac, chaddr, 6) == 0)
- || (yiaddr && g_leases[i].lease_nip == yiaddr)
- ) {
- memset(&g_leases[i], 0, sizeof(g_leases[i]));
- }
- }
-}
-
-/* Add a lease into the table, clearing out any old ones.
- * If chaddr == NULL, this is a conflict lease.
- */
-struct dyn_lease* FAST_FUNC add_lease(
- const uint8_t *chaddr, uint32_t yiaddr,
- leasetime_t leasetime,
- const char *hostname, int hostname_len)
-{
- struct dyn_lease *oldest;
-
- /* clean out any old ones */
- clear_leases(chaddr, yiaddr);
-
- oldest = oldest_expired_lease();
-
- if (oldest) {
- memset(oldest, 0, sizeof(*oldest));
- if (hostname) {
- char *p;
-
- hostname_len++; /* include NUL */
- if (hostname_len > sizeof(oldest->hostname))
- hostname_len = sizeof(oldest->hostname);
- p = safe_strncpy(oldest->hostname, hostname, hostname_len);
- /*
- * Sanitization (s/bad_char/./g).
- * The intent is not to allow only "DNS-valid" hostnames,
- * but merely make dumpleases output safe for shells to use.
- * We accept "0-9A-Za-z._-", all other chars turn to dots.
- */
- while (*p) {
- if (!isalnum(*p) && *p != '-' && *p != '_')
- *p = '.';
- p++;
- }
- }
- if (chaddr)
- memcpy(oldest->lease_mac, chaddr, 6);
- oldest->lease_nip = yiaddr;
- oldest->expires = time(NULL) + leasetime;
- }
-
- return oldest;
-}
-
-/* True if a lease has expired */
-int FAST_FUNC is_expired_lease(struct dyn_lease *lease)
-{
- return (lease->expires < (leasetime_t) time(NULL));
-}
-
-/* Find the first lease that matches MAC, NULL if no match */
-struct dyn_lease* FAST_FUNC find_lease_by_mac(const uint8_t *mac)
-{
- unsigned i;
-
- for (i = 0; i < server_config.max_leases; i++)
- if (memcmp(g_leases[i].lease_mac, mac, 6) == 0)
- return &g_leases[i];
-
- return NULL;
-}
-
-/* Find the first lease that matches IP, NULL is no match */
-struct dyn_lease* FAST_FUNC find_lease_by_nip(uint32_t nip)
-{
- unsigned i;
-
- for (i = 0; i < server_config.max_leases; i++)
- if (g_leases[i].lease_nip == nip)
- return &g_leases[i];
-
- return NULL;
-}
-
-/* Check if the IP is taken; if it is, add it to the lease table */
-static int nobody_responds_to_arp(uint32_t nip, const uint8_t *safe_mac, unsigned arpping_ms)
-{
- struct in_addr temp;
- int r;
-
- r = arpping(nip, safe_mac,
- server_config.server_nip,
- server_config.server_mac,
- server_config.interface,
- arpping_ms);
- if (r)
- return r;
-
- temp.s_addr = nip;
- bb_error_msg("%s belongs to someone, reserving it for %u seconds",
- inet_ntoa(temp), (unsigned)server_config.conflict_time);
- add_lease(NULL, nip, server_config.conflict_time, NULL, 0);
- return 0;
-}
-
-/* Find a new usable (we think) address */
-uint32_t FAST_FUNC find_free_or_expired_nip(const uint8_t *safe_mac, unsigned arpping_ms)
-{
- uint32_t addr;
- struct dyn_lease *oldest_lease = NULL;
-
-#if ENABLE_FEATURE_UDHCPD_BASE_IP_ON_MAC
- uint32_t stop;
- unsigned i, hash;
-
- /* hash hwaddr: use the SDBM hashing algorithm. Seems to give good
- * dispersal even with similarly-valued "strings".
- */
- hash = 0;
- for (i = 0; i < 6; i++)
- hash += safe_mac[i] + (hash << 6) + (hash << 16) - hash;
-
- /* pick a seed based on hwaddr then iterate until we find a free address. */
- addr = server_config.start_ip
- + (hash % (1 + server_config.end_ip - server_config.start_ip));
- stop = addr;
-#else
- addr = server_config.start_ip;
-#define stop (server_config.end_ip + 1)
-#endif
- do {
- uint32_t nip;
- struct dyn_lease *lease;
-
- /* ie, 192.168.55.0 */
- if ((addr & 0xff) == 0)
- goto next_addr;
- /* ie, 192.168.55.255 */
- if ((addr & 0xff) == 0xff)
- goto next_addr;
- nip = htonl(addr);
- /* skip our own address */
- if (nip == server_config.server_nip)
- goto next_addr;
- /* is this a static lease addr? */
- if (is_nip_reserved(server_config.static_leases, nip))
- goto next_addr;
-
- lease = find_lease_by_nip(nip);
- if (!lease) {
-//TODO: DHCP servers do not always sit on the same subnet as clients: should *ping*, not arp-ping!
- if (nobody_responds_to_arp(nip, safe_mac, arpping_ms))
- return nip;
- } else {
- if (!oldest_lease || lease->expires < oldest_lease->expires)
- oldest_lease = lease;
- }
-
- next_addr:
- addr++;
-#if ENABLE_FEATURE_UDHCPD_BASE_IP_ON_MAC
- if (addr > server_config.end_ip)
- addr = server_config.start_ip;
-#endif
- } while (addr != stop);
-
- if (oldest_lease
- && is_expired_lease(oldest_lease)
- && nobody_responds_to_arp(oldest_lease->lease_nip, safe_mac, arpping_ms)
- ) {
- return oldest_lease->lease_nip;
- }
-
- return 0;
-}
diff --git a/networking/udhcp/static_leases.c b/networking/udhcp/static_leases.c
deleted file mode 100644
index 3be7a52..0000000
--- a/networking/udhcp/static_leases.c
+++ /dev/null
@@ -1,22 +0,0 @@
-/* vi: set sw=4 ts=4: */
-/*
- * Storing and retrieving data for static leases
- *
- * Wade Berrier <wberrier at myrealbox.com> September 2004
- *
- * Licensed under GPLv2, see file LICENSE in this source tree.
- */
-#include "common.h"
-#include "dhcpd.h"
-
-/* Check to see if an IP is reserved as a static IP */
-int FAST_FUNC is_nip_reserved(struct static_lease *st_lease, uint32_t nip)
-{
- while (st_lease) {
- if (st_lease->nip == nip)
- return 1;
- st_lease = st_lease->next;
- }
-
- return 0;
-}
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