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authorDenys Vlasenko <vda.linux@googlemail.com>2010-05-30 21:41:23 (GMT)
committer Denys Vlasenko <vda.linux@googlemail.com>2010-05-30 21:41:23 (GMT)
commitb7d19cc400f14ccd64a1fedebe14022fe115029a (patch)
treecd4a50e2694628413a2460d3e1d2a706462d0e2b
parentc88c1a01904b5791dfd1ca5342c805a9f392e17f (diff)
downloadbusybox-b7d19cc400f14ccd64a1fedebe14022fe115029a.tar.gz
busybox-b7d19cc400f14ccd64a1fedebe14022fe115029a.tar.bz2
dhcp: readability cleanups and small code shrink
function old new delta udhcp_run_script 654 617 -37 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--networking/udhcp/common.c4
-rw-r--r--networking/udhcp/common.h14
-rw-r--r--networking/udhcp/dhcpc.c39
-rw-r--r--networking/udhcp/packet.c46
4 files changed, 54 insertions, 49 deletions
diff --git a/networking/udhcp/common.c b/networking/udhcp/common.c
index 7cda34a..90a07ed 100644
--- a/networking/udhcp/common.c
+++ b/networking/udhcp/common.c
@@ -176,7 +176,7 @@ unsigned FAST_FUNC udhcp_option_idx(const char *name)
}
}
-/* get an option with bounds checking (warning, result is not aligned). */
+/* Get an option with bounds checking (warning, result is not aligned) */
uint8_t* FAST_FUNC udhcp_get_option(struct dhcp_packet *packet, int code)
{
uint8_t *optionptr;
@@ -240,7 +240,7 @@ uint8_t* FAST_FUNC udhcp_get_option(struct dhcp_packet *packet, int code)
return NULL;
}
-/* return the position of the 'end' option (no bounds checking) */
+/* Return the position of the 'end' option (no bounds checking) */
int FAST_FUNC udhcp_end_option(uint8_t *optionptr)
{
int i = 0;
diff --git a/networking/udhcp/common.h b/networking/udhcp/common.h
index c9dd0bb..75b787a 100644
--- a/networking/udhcp/common.h
+++ b/networking/udhcp/common.h
@@ -57,10 +57,20 @@ struct ip_udp_dhcp_packet {
struct dhcp_packet data;
} PACKED;
+struct udp_dhcp_packet {
+ struct udphdr udp;
+ struct dhcp_packet data;
+} PACKED;
+
+enum {
+ IP_UPD_DHCP_SIZE = sizeof(struct ip_udp_dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS,
+ UPD_DHCP_SIZE = sizeof(struct udp_dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS,
+ DHCP_SIZE = sizeof(struct dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS,
+};
+
/* Let's see whether compiler understood us right */
struct BUG_bad_sizeof_struct_ip_udp_dhcp_packet {
- char BUG_bad_sizeof_struct_ip_udp_dhcp_packet
- [(sizeof(struct ip_udp_dhcp_packet) != 576 + CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS) ? -1 : 1];
+ char c[IP_UPD_DHCP_SIZE == 576 ? 1 : -1];
};
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index 24ff82d..c2b21c6 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -229,37 +229,41 @@ static NOINLINE char *xmalloc_optname_optval(uint8_t *option, const struct dhcp_
/* put all the parameters into the environment */
static char **fill_envp(struct dhcp_packet *packet)
{
- int num_options = 0;
+ int envc;
int i;
char **envp, **curr;
const char *opt_name;
uint8_t *temp;
- uint8_t over = 0;
-
+ uint8_t overload = 0;
+
+ /* We need 6 elements for:
+ * "interface=IFACE"
+ * "ip=N.N.N.N" from packet->yiaddr
+ * "siaddr=IP" from packet->siaddr_nip (unless 0)
+ * "boot_file=FILE" from packet->file (unless overloaded)
+ * "sname=SERVER_HOSTNAME" from packet->sname (unless overloaded)
+ * terminating NULL
+ */
+ envc = 6;
+ /* +1 element for each option, +2 for subnet option: */
if (packet) {
for (i = 0; dhcp_optflags[i].code; i++) {
if (udhcp_get_option(packet, dhcp_optflags[i].code)) {
- num_options++;
if (dhcp_optflags[i].code == DHCP_SUBNET)
- num_options++; /* for mton */
+ envc++; /* for mton */
+ envc++;
}
}
- if (packet->siaddr_nip)
- num_options++;
temp = udhcp_get_option(packet, DHCP_OPTION_OVERLOAD);
if (temp)
- over = *temp;
- if (!(over & FILE_FIELD) && packet->file[0])
- num_options++;
- if (!(over & SNAME_FIELD) && packet->sname[0])
- num_options++;
+ overload = *temp;
}
+ curr = envp = xzalloc(sizeof(char *) * envc);
- curr = envp = xzalloc(sizeof(char *) * (num_options + 3));
*curr = xasprintf("interface=%s", client_config.interface);
putenv(*curr++);
- if (packet == NULL)
+ if (!packet)
return envp;
*curr = xmalloc(sizeof("ip=255.255.255.255"));
@@ -274,9 +278,8 @@ static char **fill_envp(struct dhcp_packet *packet)
goto next;
*curr = xmalloc_optname_optval(temp, &dhcp_optflags[i], opt_name);
putenv(*curr++);
-
- /* Fill in a subnet bits option for things like /24 */
if (dhcp_optflags[i].code == DHCP_SUBNET) {
+ /* Subnet option: make things like "$ip/$mask" possible */
uint32_t subnet;
move_from_unaligned32(subnet, temp);
*curr = xasprintf("mask=%d", mton(subnet));
@@ -291,12 +294,12 @@ static char **fill_envp(struct dhcp_packet *packet)
sprint_nip(*curr, "siaddr=", (uint8_t *) &packet->siaddr_nip);
putenv(*curr++);
}
- if (!(over & FILE_FIELD) && packet->file[0]) {
+ if (!(overload & FILE_FIELD) && packet->file[0]) {
/* watch out for invalid packets */
*curr = xasprintf("boot_file=%."DHCP_PKT_FILE_LEN_STR"s", packet->file);
putenv(*curr++);
}
- if (!(over & SNAME_FIELD) && packet->sname[0]) {
+ if (!(overload & SNAME_FIELD) && packet->sname[0]) {
/* watch out for invalid packets */
*curr = xasprintf("sname=%."DHCP_PKT_SNAME_LEN_STR"s", packet->sname);
putenv(*curr++);
diff --git a/networking/udhcp/packet.c b/networking/udhcp/packet.c
index 1bfe120..c01fb7d 100644
--- a/networking/udhcp/packet.c
+++ b/networking/udhcp/packet.c
@@ -167,44 +167,40 @@ uint16_t FAST_FUNC udhcp_checksum(void *addr, int count)
/* Construct a ip/udp header for a packet, send packet */
int FAST_FUNC udhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt,
- uint32_t source_ip, int source_port,
- uint32_t dest_ip, int dest_port, const uint8_t *dest_arp,
+ uint32_t source_nip, int source_port,
+ uint32_t dest_nip, int dest_port, const uint8_t *dest_arp,
int ifindex)
{
- struct sockaddr_ll dest;
+ struct sockaddr_ll dest_sll;
struct ip_udp_dhcp_packet packet;
int fd;
int result = -1;
const char *msg;
- enum {
- IP_UPD_DHCP_SIZE = sizeof(struct ip_udp_dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS,
- UPD_DHCP_SIZE = IP_UPD_DHCP_SIZE - offsetof(struct ip_udp_dhcp_packet, udp),
- };
-
fd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP));
if (fd < 0) {
msg = "socket(%s)";
goto ret_msg;
}
- memset(&dest, 0, sizeof(dest));
- memset(&packet, 0, sizeof(packet));
+ memset(&dest_sll, 0, sizeof(dest_sll));
+ memset(&packet, 0, offsetof(struct ip_udp_dhcp_packet, data));
packet.data = *dhcp_pkt; /* struct copy */
- dest.sll_family = AF_PACKET;
- dest.sll_protocol = htons(ETH_P_IP);
- dest.sll_ifindex = ifindex;
- dest.sll_halen = 6;
- memcpy(dest.sll_addr, dest_arp, 6);
- if (bind(fd, (struct sockaddr *)&dest, sizeof(dest)) < 0) {
+ dest_sll.sll_family = AF_PACKET;
+ dest_sll.sll_protocol = htons(ETH_P_IP);
+ dest_sll.sll_ifindex = ifindex;
+ dest_sll.sll_halen = 6;
+ memcpy(dest_sll.sll_addr, dest_arp, 6);
+
+ if (bind(fd, (struct sockaddr *)&dest_sll, sizeof(dest_sll)) < 0) {
msg = "bind(%s)";
goto ret_close;
}
packet.ip.protocol = IPPROTO_UDP;
- packet.ip.saddr = source_ip;
- packet.ip.daddr = dest_ip;
+ packet.ip.saddr = source_nip;
+ packet.ip.daddr = dest_nip;
packet.udp.source = htons(source_port);
packet.udp.dest = htons(dest_port);
/* size, excluding IP header: */
@@ -225,7 +221,7 @@ int FAST_FUNC udhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt,
*/
udhcp_dump_packet(dhcp_pkt);
result = sendto(fd, &packet, IP_UPD_DHCP_SIZE, 0,
- (struct sockaddr *) &dest, sizeof(dest));
+ (struct sockaddr *) &dest_sll, sizeof(dest_sll));
msg = "sendto";
ret_close:
close(fd);
@@ -239,18 +235,14 @@ int FAST_FUNC udhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt,
/* Let the kernel do all the work for packet generation */
int FAST_FUNC udhcp_send_kernel_packet(struct dhcp_packet *dhcp_pkt,
- uint32_t source_ip, int source_port,
- uint32_t dest_ip, int dest_port)
+ uint32_t source_nip, int source_port,
+ uint32_t dest_nip, int dest_port)
{
struct sockaddr_in client;
int fd;
int result = -1;
const char *msg;
- enum {
- DHCP_SIZE = sizeof(struct dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS,
- };
-
fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
if (fd < 0) {
msg = "socket(%s)";
@@ -261,7 +253,7 @@ int FAST_FUNC udhcp_send_kernel_packet(struct dhcp_packet *dhcp_pkt,
memset(&client, 0, sizeof(client));
client.sin_family = AF_INET;
client.sin_port = htons(source_port);
- client.sin_addr.s_addr = source_ip;
+ client.sin_addr.s_addr = source_nip;
if (bind(fd, (struct sockaddr *)&client, sizeof(client)) == -1) {
msg = "bind(%s)";
goto ret_close;
@@ -270,7 +262,7 @@ int FAST_FUNC udhcp_send_kernel_packet(struct dhcp_packet *dhcp_pkt,
memset(&client, 0, sizeof(client));
client.sin_family = AF_INET;
client.sin_port = htons(dest_port);
- client.sin_addr.s_addr = dest_ip;
+ client.sin_addr.s_addr = dest_nip;
if (connect(fd, (struct sockaddr *)&client, sizeof(client)) == -1) {
msg = "connect";
goto ret_close;