LWIP - dhcpd --lwip

A sort of quick hack for dhcpd to work as a client with lwip server.

- The functionality is not changed unless --lwip switch is supplied.
  dhcpd does not use broadcast udp sockets but some sort of raw
  sockets and changes their behavior during their life by ioctls.

- I thought there is no need to polute lwip just to make dhcp client
  work. Instead I decided to twist the client a little bit.

- It is so far the only big collision I found between inet and lwip.

commands/dhcpd/devices.c

@@ -16,6 +16,8 @@
 #include <sys/asynchio.h>
 #include <net/hton.h>
 #include <net/gen/in.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
 #include <net/gen/ether.h>
 #include <net/gen/eth_hdr.h>
 #include <net/gen/eth_io.h>
@@ -166,6 +168,9 @@ int opendev(network_t *np, fdtype_t fdtype, int compete)
     /* Open the proper device in the proper mode. */
     fdp= fdold;
     fdp->n= np->n;
+    if (lwip && (fdtype == FT_ETHERNET || fdtype == FT_ICMP))
+	    sprintf(fdp->device, "/dev/ip");
+    else
 	    sprintf(fdp->device, "/dev/%s%d", devbytype[fdtype], np->n);
     np->fdp= fdp;
 
@@ -176,6 +181,38 @@ int opendev(network_t *np, fdtype_t fdtype, int compete)
 
     switch (fdtype) {
     case FT_ETHERNET:
+	 if (lwip) {
+		 nwio_ipopt_t ipopt;
+		 int result;
+		 char ethdev[64];
+		 int efd;
+		 
+		 sprintf(ethdev, "/dev/eth%d", np->n);
+    
+		 if ((efd = open(fdp->device, O_RDWR)) < 0) {
+			 if (errno == ENOENT || errno == ENODEV ||
+					 errno == ENXIO)
+				 return 0;
+			 fatal(ethdev);
+		 }
+	
+		 if (ioctl(efd, NWIOGETHSTAT, &ethstat) < 0) {
+			 /* Not an Ethernet. */
+			 close(efd);
+			 return 0;
+		 }
+		 close(efd);
+
+		 np->eth= ethstat.nwes_addr;
+
+		 ipopt.nwio_flags= NWIO_COPY | NWIO_PROTOSPEC;
+		 ipopt.nwio_proto= 17; /* UDP */
+		 result= ioctl (fdp->fd, NWIOSIPOPT, &ipopt);
+		 if (result<0)
+			 perror("ioctl (NWIOSIPOPT)"), exit(1);
+
+		 break;
+	 }
 	/* Cannot use NWIOGETHSTAT in non-blocking mode due to a race between 
          * the reply from the ethernet driver and the cancel message from VFS
 	 * for reaching inet. Hence, a signal is used to interrupt NWIOGETHSTAT
@@ -218,6 +255,26 @@ int opendev(network_t *np, fdtype_t fdtype, int compete)
 	break;
 
     case FT_BOOTPC:
+	if (lwip) {
+		struct sockaddr_in si_me;
+
+		close(fdp->fd);
+		fdp->fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
+		if (fdp->fd < 0)
+			return 0;
+		memset((char *) &si_me, 0, sizeof(si_me));
+		si_me.sin_family = AF_INET;
+		si_me.sin_addr.s_addr = htonl(INADDR_ANY);
+		si_me.sin_port = htons(port_client);
+		if (bind(fdp->fd, (struct sockaddr *) &si_me,
+					sizeof(si_me)) == -1) {
+			close(fdp->fd);
+			printf("DHCP : cannot bind client socket to port %d\n",
+								port_client);
+			return 0;
+		}
+		break;
+	}
 	udpopt.nwuo_flags= NWUO_COPY | NWUO_EN_LOC | NWUO_EN_BROAD
 			| NWUO_RP_ANY | NWUO_RA_ANY | NWUO_RWDATALL
 			| NWUO_DI_IPOPT | NWUO_LP_SET;

commands/dhcpd/dhcpd.c

@@ -45,6 +45,8 @@ static int aflag, rflag;	/* True if adding or deleting pool addresses. */
 #define N_NETS		32
 static unsigned n_nets;		/* Actual number of networks. */
 
+int lwip;
+
 void report(const char *label)
 {
     static FILE *logfp;
@@ -686,6 +688,11 @@ main:
 
 	if (opt[0] == '-' && opt[1] == 0) break;	/* -- */
 	
+	if (strcmp(opt, "-lwip") == 0) {
+		lwip = 1;
+		continue;
+	}
+
 	while (*opt != 0) switch (*opt++) {
 	case 'f':
 	    if (*opt == 0) {
@@ -776,7 +783,9 @@ main:
 	np->n= i;
 
 	/* Ethernet? */
-	if (opendev(np, FT_ETHERNET, 1)) {
+	if (lwip) {
+		np->type = NT_ETHERNET;
+	} else if (opendev(np, FT_ETHERNET, 1)) {
 	    np->type= B(&np->eth)[0] != 'Z' ? NT_ETHERNET : NT_SINK;
 	    if (debug >= 1) {
 		printf("%s: Ethernet address is %s%s\n",
@@ -956,8 +965,8 @@ main:
 		if (!(np->flags & NF_BOUND)) {
 		    /* Rebind over Ethernet. */
 		    udp2ether(bp, np);
-		    if (sendpacket(np, bp->eth, 
-		    			sizeof(eth_hdr_t) + sizeof(ip_hdr_t)
+		    if (sendpacket(np, (lwip ? bp->ip : bp->eth), 
+		    			(lwip ? 0 : sizeof(eth_hdr_t)) + sizeof(ip_hdr_t)
 					+ sizeof(udp_hdr_t) + sizeof(dhcp_t))) {
 			if (debug >= 1) {
 			    printf("%s: Broadcast DHCP %s\n",
@@ -1007,8 +1016,9 @@ main:
 	    if (!(np->flags & NF_BOUND)) {
 		if (!opendev(np, FT_ETHERNET, 0)) continue;
 		get_buf(&np->fdp->bp);
-		r= asyn_read(&asyn, np->fdp->fd, np->fdp->bp->eth,
-							BUF_ETH_SIZE);
+		r= asyn_read(&asyn, np->fdp->fd,
+				lwip ? np->fdp->bp->ip : np->fdp->bp->eth,
+				lwip ? BUF_IP_SIZE : BUF_ETH_SIZE);
 	    } else {
 		if (!opendev(np, FT_BOOTPC, 0)) continue;
 		get_buf(&np->fdp->bp);
@@ -1026,7 +1036,7 @@ main:
 	if (i < n_nets) {
 	    give_buf(&bp, &np->fdp->bp);
 	    if (((!(np->flags & NF_BOUND)
-		    && r >= (sizeof(eth_hdr_t) + sizeof(ip_hdr_t)
+		    && r >= (lwip ? 0 : (sizeof(eth_hdr_t)) + sizeof(ip_hdr_t)
 				+ sizeof(udp_hdr_t) + offsetof(dhcp_t, options))
 		    && ether2udp(bp)
 		    && bp->udpio->uih_dst_port == port_client)

commands/dhcpd/dhcpd.h

@@ -19,6 +19,8 @@
 #define EXTERN	extern
 #endif
 
+extern int lwip;
+
 EXTERN char *program;		/* This program's name. */
 extern char *configfile;	/* Configuration file. */
 extern char *poolfile;		/* Dynamic address pool. */