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dhcp: readability cleanups and small code shrink

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function                                             old     new   delta
udhcp_run_script                                     654     617     -37

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2010-05-30 23:41:23 +02:00
parent c88c1a0190
commit b7d19cc400
4 changed files with 53 additions and 48 deletions
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4
networking/udhcp/common.c
View File

@ -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;

14
networking/udhcp/common.h
View File

@ -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];
};

37
networking/udhcp/dhcpc.c
View File

@ -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++);

46
networking/udhcp/packet.c
View File

@ -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;