cleanup (WIP) - sdhcp - simple dhcp client
(HTM) git clone git://git.codemadness.org/sdhcp
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(DIR) Files
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(DIR) LICENSE
---
(DIR) commit 3e2bf1a43fc43b90a8d1bc2ffae62b83b765cb84
(DIR) parent 45c39c4a1772a01d0d37a26f2a92e3fa2f5a750e
(HTM) Author: Hiltjo Posthuma <hiltjo@codemadness.org>
Date: Fri, 25 Apr 2014 19:26:40 +0200
cleanup (WIP)
- code style, trailing whitespace and use tabs
- add some notes for further cleanup
- remove dbgprintf() code in sdhcp.c
- make exit(n), EXIT_SUCCESS or EXIT_FAILURE
Signed-off-by: Hiltjo Posthuma <hiltjo@codemadness.org>
Diffstat:
M sdhcp.c | 412 +++++++++++++++++--------------
1 file changed, 220 insertions(+), 192 deletions(-)
---
(DIR) diff --git a/sdhcp.c b/sdhcp.c
@@ -1,97 +1,99 @@
-#include<sys/socket.h>
-#include<sys/ioctl.h>
-#include<netinet/in.h>
-#include<net/if.h>
-#include<net/route.h>
-#include<signal.h>
-#include<poll.h>
-#include<errno.h>
-#include<fcntl.h>
-#include<stdio.h>
-#include<stdlib.h>
-#include<string.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+#include <netinet/in.h>
+#include <net/if.h>
+#include <net/route.h>
+#include <signal.h>
+#include <poll.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
#define MIN(a,b) (((a)<(b))?(a):(b))
-typedef unsigned char uchar;
-typedef struct Bootp Bootp;
-struct Bootp {
- uchar op [1];
- uchar htype [1];
- uchar hlen [1];
- uchar hops [1];
- uchar xid [4];
- uchar secs [2];
- uchar flags [2];
- uchar ciaddr [4];
- uchar yiaddr [4];
- uchar siaddr [4];
- uchar giaddr [4];
- uchar chaddr [16];
- uchar sname [64];
- uchar file [128];
- uchar magic [4];
- uchar optdata [312-4];
-};
-void bpdump(uchar *p, int n);
-enum {
- DHCPdiscover = 1, DHCPoffer, DHCPrequest,
- DHCPdecline, DHCPack, DHCPnak, DHCPrelease,
- DHCPinform, Timeout=200,
+typedef struct bootp {
+ unsigned char op [1];
+ unsigned char htype [1];
+ unsigned char hlen [1];
+ unsigned char hops [1];
+ unsigned char xid [4];
+ unsigned char secs [2];
+ unsigned char flags [2];
+ unsigned char ciaddr [4];
+ unsigned char yiaddr [4];
+ unsigned char siaddr [4];
+ unsigned char giaddr [4];
+ unsigned char chaddr [16];
+ unsigned char sname [64];
+ unsigned char file [128];
+ unsigned char magic [4];
+ unsigned char optdata [312-4];
+} Bootp;
+
+enum {
+ DHCPdiscover = 1,
+ DHCPoffer,
+ DHCPrequest,
+ DHCPdecline,
+ DHCPack,
+ DHCPnak,
+ DHCPrelease,
+ DHCPinform,
+ Timeout = 200,
- Bootrequest= 1,
- Bootreply= 2,
+ Bootrequest = 1,
+ Bootreply = 2,
/* bootp flags */
- Fbroadcast= 1<<15,
-
- OBpad= 0,
- OBmask= 1,
- OBrouter= 3,
- OBnameserver= 5,
- OBdnsserver= 6,
- OBbaddr= 28,
- ODipaddr= 50, /* 0x32 */
- ODlease= 51,
- ODoverload= 52,
- ODtype= 53, /* 0x35 */
- ODserverid= 54, /* 0x36 */
- ODparams= 55, /* 0x37 */
- ODmessage= 56,
- ODmaxmsg= 57,
- ODrenewaltime= 58,
- ODrebindingtime= 59,
- ODvendorclass= 60,
- ODclientid= 61, /* 0x3d */
- ODtftpserver= 66,
- ODbootfile= 67,
- OBend= 255,
+ Fbroadcast = 1<<15,
+
+ OBpad = 0,
+ OBmask = 1,
+ OBrouter = 3,
+ OBnameserver = 5,
+ OBdnsserver = 6,
+ OBbaddr = 28,
+ ODipaddr = 50, /* 0x32 */
+ ODlease = 51,
+ ODoverload = 52,
+ ODtype = 53, /* 0x35 */
+ ODserverid = 54, /* 0x36 */
+ ODparams = 55, /* 0x37 */
+ ODmessage = 56,
+ ODmaxmsg = 57,
+ ODrenewaltime = 58,
+ ODrebindingtime = 59,
+ ODvendorclass = 60,
+ ODclientid = 61, /* 0x3d */
+ ODtftpserver = 66,
+ ODbootfile = 67,
+ OBend = 255,
};
-enum{ Broadcast, Unicast};
+enum { Broadcast, Unicast};
Bootp bp;
-uchar magic[] = {99, 130, 83, 99};
-
-//struct conf{
- uchar xid[sizeof bp.xid];
- uchar hwaddr[16];
- time_t starttime;
- char *ifname = "eth0";
- char *cid = "vaio.12340";
- int sock;
-//} var;
-//struct sav{
- uchar server[4];
- uchar client[4];
- uchar mask[4];
- uchar router[4];
- uchar dns[4];
- unsigned long t1;
- unsigned long t2;
-//} sav;
-
-#define IP(...) (uchar[4]){__VA_ARGS__}
+unsigned char magic[] = {99, 130, 83, 99};
+
+/* conf */
+unsigned char xid[sizeof bp.xid];
+unsigned char hwaddr[16];
+time_t starttime;
+char *ifname = "eth0";
+char *cid = "vaio.12340";
+int sock;
+/* sav */
+unsigned char server[4];
+unsigned char client[4];
+unsigned char mask[4];
+unsigned char router[4];
+unsigned char dns[4];
+unsigned long t1;
+unsigned long t2;
+
+#define IP(...) (unsigned char[4]){__VA_ARGS__}
static void
die(char *str)
@@ -101,25 +103,27 @@ die(char *str)
}
static void
-hnput(uchar *dst, unsigned long long src, int n)
+hnput(unsigned char *dst, unsigned long long src, int n)
{
- int x;
- for(x=0; n--; x++)
- dst[x] = (src>>(n*8))&0xff;
+ int i;
+
+ for(i = 0; n--; i++) /* TODO: --n ? */
+ dst[i] = (src >> (n * 8)) & 0xff;
}
static struct sockaddr
-iptoaddr(uchar ip[4], int port)
+iptoaddr(unsigned char ip[4], int port)
{
struct sockaddr_in ifaddr;
- ifaddr.sin_family=AF_INET;
+
+ ifaddr.sin_family = AF_INET;
ifaddr.sin_port = htons(port);
memcpy(&ifaddr.sin_addr, ip, sizeof ifaddr.sin_addr);
return *(struct sockaddr*)&ifaddr;
}
#define UDPWRAPPER(name, func, port, hack) \
-static int name(uchar ip[4], int fd, void *data, size_t n){\
+static int name(unsigned char ip[4], int fd, void *data, size_t n){\
struct sockaddr addr = iptoaddr(ip, port);\
int x, y = sizeof addr;\
if((x=func(fd, data, n, 0, &addr, hack y))==-1)\
@@ -130,19 +134,19 @@ UDPWRAPPER(udpsend, sendto, 67, )
UDPWRAPPER(udprecv, recvfrom, 68, &)
static void
-setip(uchar ip[4], uchar mask[4], uchar gateway[4])
+setip(unsigned char ip[4], unsigned char mask[4], unsigned char gateway[4])
{
int fd, x;
struct ifreq ifreq = {0,};
struct rtentry rtreq = {0,};
fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
- strcpy(ifreq.ifr_name, ifname);
+ strcpy(ifreq.ifr_name, ifname); /*TODO: strlcpy */
ifreq.ifr_addr = iptoaddr(ip, 0);
ioctl(fd, SIOCSIFADDR , &ifreq);
ifreq.ifr_netmask = iptoaddr(mask, 0);
ioctl(fd, SIOCSIFNETMASK , &ifreq);
- ifreq.ifr_flags=IFF_UP|IFF_RUNNING|IFF_BROADCAST|IFF_MULTICAST;
+ ifreq.ifr_flags = IFF_UP|IFF_RUNNING|IFF_BROADCAST|IFF_MULTICAST;
ioctl(fd, SIOCSIFFLAGS , &ifreq);
rtreq.rt_flags = (RTF_UP | RTF_GATEWAY);
@@ -153,93 +157,106 @@ setip(uchar ip[4], uchar mask[4], uchar gateway[4])
close(fd);
}
-static void
+
+static void
cat(int dfd, char *src)
{
- char buf[4096];
+ char buf[4096]; /* TODO: use BUFSIZ ? */
int n, sfd = open(src, O_RDONLY);
- while((n=read(sfd, buf, sizeof buf))>0)
+
+ while((n = read(sfd, buf, sizeof buf))>0)
write(dfd, buf, n);
close(sfd);
}
-//use itoa not sprintf to make dietlibc happy.
-char* itoa(char * str, int x)
+
+/* use itoa not sprintf to make dietlibc happy. */
+/* TODO: use snprintf(), fuck dietlibc */
+char *
+itoa(char * str, int x)
{
- if(x==0){
+ int k = 1;
+ char *ep = str;
+
+ if(x == 0) {
*str='0';
return str+1;
}
- int k = 1;
- char *ep = str;
- while(x/k > 0)
- k*=10;
- while((k/=10)>=1)
- *ep++ = '0'+((x/k)%10);
- *ep = '\0';
- return str+strlen(str);
+ while(x / k > 0)
+ k *= 10;
+ while((k /= 10) >= 1)
+ *ep++ = '0' + ((x / k) % 10);
+ *ep = '\0';
+ return str + strlen(str);
}
+
static void
-setdns(uchar dns[4])
+setdns(unsigned char dns[4])
{
char buf[128], *bp = buf;
int fd = creat("/etc/resolv.conf", 0644);
+
cat(fd, "/etc/resolv.conf.head");
memcpy(buf, "\nnameserver ", 12), bp+=11;
- *(bp=itoa(bp+1, dns[0])) = '.';
- *(bp=itoa(bp+1, dns[1])) = '.';
- *(bp=itoa(bp+1, dns[2])) = '.';
- *(bp=itoa(bp+1, dns[3])) = '\n';
+ *(bp = itoa(bp+1, dns[0])) = '.';
+ *(bp = itoa(bp+1, dns[1])) = '.';
+ *(bp = itoa(bp+1, dns[2])) = '.';
+ *(bp = itoa(bp+1, dns[3])) = '\n';
*++bp = '\0';
write(fd, buf, strlen(buf));
cat(fd, "/etc/resolv.conf.tail");
close(fd);
}
-static uchar *
+static unsigned char *
optget(Bootp *bp, void *data, int opt, int n)
{
- uchar *p = bp->optdata;
- uchar *top = ((uchar*)bp)+sizeof *bp;
- while(p<top){
- int code = *p++;
- if(code==OBpad)
+ unsigned char *p = bp->optdata;
+ unsigned char *top = ((unsigned char *)bp) + sizeof *bp;
+ int code;
+ int len;
+
+ while(p < top) {
+ code = *p++;
+ if(code == OBpad)
continue;
- if(code==OBend || p==top)
+ if(code == OBend || p == top)
break;
- int len = *p++;
+ len = *p++;
if(len > top-p)
break;
- if(code==opt){
+ if(code == opt) {
memcpy(data, p, MIN(len, n));
return p;
}
- p+=len;
+ p += len;
}
}
-static uchar *
-optput(uchar *p, int opt, uchar *data, int len)
+static unsigned char *
+optput(unsigned char *p, int opt, unsigned char *data, int len)
{
*p++ = opt;
- *p++ = (uchar)len;
+ *p++ = (unsigned char)len;
memcpy(p, data, len);
- return p+len;
+ return p + len;
}
-static uchar*
-hnoptput(uchar *p, int opt, long long data, int len)
+
+static unsigned char *
+hnoptput(unsigned char *p, int opt, long long data, int len)
{
- *p++=opt;
- *p++ = (uchar)len;
+ *p++ = opt;
+ *p++ = (unsigned char)len;
hnput(p, data, len);
return p+len;
}
-#include "debug.c"
static void
dhcpsend(int type, int how)
{
- dbgprintf("\nSending ");
+ unsigned char *ip;
+ unsigned char *p;
+
memset(&bp, 0, sizeof bp);
hnput(bp.op, Bootrequest, 1);
hnput(bp.htype, 1, 1);
@@ -249,15 +266,15 @@ dhcpsend(int type, int how)
hnput(bp.secs, time(NULL)-starttime, sizeof bp.secs);
memcpy(bp.magic, magic, sizeof bp.magic);
memcpy(bp.chaddr, hwaddr, sizeof bp.chaddr);
- uchar *p = bp.optdata;
+ p = bp.optdata;
p = hnoptput(p, ODtype, type, 1);
p = optput(p, ODclientid, cid, strlen(cid));
- switch(type){
+ switch(type) {
case DHCPdiscover:
break;
case DHCPrequest:
-// memcpy(bp.ciaddr, client, sizeof bp.ciaddr);
+ /* memcpy(bp.ciaddr, client, sizeof bp.ciaddr); */
p = hnoptput(p, ODlease, t1, sizeof t1);
p = optput(p, ODipaddr, client, sizeof client);
p = optput(p, ODserverid, server, sizeof server);
@@ -268,33 +285,37 @@ dhcpsend(int type, int how)
p = optput(p, ODserverid, server, sizeof server);
break;
}
- *p++=OBend;
- bpdump((void*)&bp, p-(uchar*)&bp);
- uchar *ip = (how==Broadcast)?IP(255,255,255,255):server;
- udpsend(ip, sock, &bp, p-(uchar*)&bp);
+ *p++ = OBend;
+ /* debug */
+ /*bpdump((void*)&bp, p - (unsigned char *)&bp);*/
+
+ ip = (how == Broadcast) ? IP(255,255,255,255) : server;
+ udpsend(ip, sock, &bp, p - (unsigned char *)&bp);
}
static int
-dhcprecv()
+dhcprecv(void)
{
- dbgprintf("\nReceiving ");
+ unsigned char type;
+ int x;
+
memset(&bp, 0, sizeof bp);
- struct pollfd pfd = {sock, POLLIN};
- if(poll(&pfd, 1, -1)==-1){
- if(errno!=EINTR)
+ struct pollfd pfd = {sock, POLLIN}; /* TODO: not inline */
+ if(poll(&pfd, 1, -1) == -1) {
+ if(errno != EINTR)
die("poll");
else
return Timeout;
}
- int x = udprecv(IP(255,255,255,255), sock, &bp, sizeof bp);
- bpdump((void*)&bp, x);
- uchar type;
+ x = udprecv(IP(255,255,255,255), sock, &bp, sizeof bp);
+ /* debug */
+ /* bpdump((void*)&bp, x);*/
optget(&bp, &type, ODtype, sizeof type);
return type;
}
static void
-acceptlease()
+acceptlease(void)
{
setip(client, mask, router);
setdns(dns);
@@ -302,37 +323,35 @@ acceptlease()
}
static void
-run()
+run(void)
{
#if 0
InitReboot:
- //send DHCPrequest to old server
+ /* send DHCPrequest to old server */
dhcpsend(DHCPrequest, Broadcasr);
goto Rebooting;
Rebooting:
- switch (dhcprecv()){
+ switch (dhcprecv()) {
case DHCPnak:
goto Init;
case DHCPack:
acceptoffer();
- goto Bound;
+ goto Bound;
}
#endif
Init:
- dbgprintf("\n\n------- Init ------\n");
dhcpsend(DHCPdiscover, Broadcast);
alarm(1);
goto Selecting;
Selecting:
- dbgprintf("\n\n------- Selecting ------\n");
- switch(dhcprecv()){
+ switch(dhcprecv()) {
case DHCPoffer:
alarm(0);
memcpy(client, bp.yiaddr, sizeof client);
optget(&bp, server, ODserverid, sizeof server);
- optget(&bp, mask, OBmask, sizeof mask);
- optget(&bp, router, OBrouter, sizeof router);
- optget(&bp, dns, OBdnsserver, sizeof dns);
+ optget(&bp, mask, OBmask, sizeof mask);
+ optget(&bp, router, OBrouter, sizeof router);
+ optget(&bp, dns, OBdnsserver, sizeof dns);
optget(&bp, &t1, ODlease, sizeof t1);
t1 = ntohl(t1);
dhcpsend(DHCPrequest, Broadcast);
@@ -343,49 +362,47 @@ Selecting:
goto Selecting;
}
Requesting:
- dbgprintf("\n\n------- Requesting ------\n");
- switch(dhcprecv()){
+ switch(dhcprecv()) {
case DHCPoffer:
- goto Requesting; //ignore other offers.
-// case DHCPack: //(and you don't want it)?
-// dhcpsend(DHCPdecline, Unicast);
-// goto Init;
+ goto Requesting; /* ignore other offers. */
+#if 0
+ case DHCPack: /* (and you don't want it) ? */
+ dhcpsend(DHCPdecline, Unicast);
+ goto Init;
+#endif
case DHCPack:
acceptlease();
goto Bound;
}
Bound:
- dbgprintf("\n\n------- Bound ------\n");
- write(1, "Congrats! You should be on the 'net.\n", 37);
+ fputs("Congrats! You should be on the 'net.\n", stdout);
if(fork())
- exit(0);
- switch (dhcprecv()){
+ exit(EXIT_SUCCESS);
+ switch (dhcprecv()) {
case DHCPoffer:
case DHCPack:
case DHCPnak:
- goto Bound; //discard offer, ack, or nak
+ goto Bound; /* discard offer, ack, or nak */
case Timeout:
dhcpsend(DHCPrequest, Unicast);
- goto Renewing;
+ goto Renewing;
}
Renewing:
- dbgprintf("\n\n------- Renewing ------\n");
- switch(dhcprecv()){
+ switch(dhcprecv()) {
case DHCPack:
acceptlease();
goto Bound;
case DHCPnak:
- //halt network;
+ /* halt network; */
goto Init;
- case Timeout: //t2 expires:
+ case Timeout: /* t2 expires: */
dhcpsend(DHCPrequest, Broadcast);
goto Rebinding;
}
Rebinding:
- dbgprintf("\n\n------- Rebinding ------\n");
- switch(dhcprecv()){
- case DHCPnak: //lease expired
- //halt network;
+ switch(dhcprecv()) {
+ case DHCPnak: /* lease expired */
+ /* halt network; */
goto Init;
case DHCPack:
acceptlease();
@@ -393,19 +410,31 @@ Rebinding:
}
}
-static void nop(int unused){ }
-static void cleanexit(int unused){
+static void nop(int unused) {
+}
+
+static void cleanexit(int unused) {
dhcpsend(DHCPrelease, Unicast);
- exit(0);
+ exit(EXIT_SUCCESS);
+}
+
+static void
+usage(void) {
fputs("usage: sdhcp [interface]\n", stderr);
+ exit(EXIT_FAILURE);
}
int
main(int argc, char *argv[])
{
- if(argc>2){
- exit(EXIT_FAILURE);
- }if(argc==2)
+ int bcast = 1;
+ struct ifreq ifreq = {0,};
+ struct sockaddr addr;
+ int rnd;
+
+ if(argc > 2)
+ usage();
+ else if(argc == 2)
ifname = argv[1];
signal(SIGALRM, nop);
@@ -413,24 +442,23 @@ main(int argc, char *argv[])
if((sock = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
die("socket");
- int bcast = 1;
if(setsockopt(sock, SOL_SOCKET, SO_BROADCAST, &bcast, sizeof bcast)==-1)
die("setsockopt");
- struct ifreq ifreq = {0,};
- strcpy(ifreq.ifr_name, ifname);
+
+ strcpy(ifreq.ifr_name, ifname); /* TODO: strlcpy */
ioctl(sock, SIOCGIFINDEX, &ifreq);
if(setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, &ifreq, sizeof ifreq)==-1)
die("setsockopt");
- struct sockaddr addr = iptoaddr(IP(255,255,255,255), 68);
+ addr = iptoaddr(IP(255,255,255,255), 68);
if(bind(sock, (void*)&addr, sizeof addr)!=0)
die("bind");
ioctl(sock, SIOCGIFHWADDR, &ifreq);
memcpy(hwaddr, ifreq.ifr_hwaddr.sa_data, sizeof ifreq.ifr_hwaddr.sa_data);
- int rnd = open("/dev/urandom", O_RDONLY);
+ rnd = open("/dev/urandom", O_RDONLY);
read(rnd, xid, sizeof xid);
close(rnd);
- starttime = time(NULL);
+ starttime = time(NULL);
run();
- return 0;
+ return EXIT_SUCCESS;
}