From: Roy Marples <roy@marples.name>
Date: Fri, 13 May 2016 15:41:58 +0000 (+0000)
Subject: Rework the raw packet API so we work directly with a fd.
X-Git-Tag: v6.11.1~51
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=76c1b6856370f8659f789018b89f86279aeccf20;p=thirdparty%2Fdhcpcd.git

Rework the raw packet API so we work directly with a fd.
It's possible the underlying mechanism might not use the fd as a primary
resource, so add the if_closeraw() function.
---

diff --git a/arp.c b/arp.c
index 20fcd7ae..30cc3aea 100644
--- a/arp.c
+++ b/arp.c
@@ -62,6 +62,7 @@ arp_request(const struct interface *ifp, in_addr_t sip, in_addr_t tip)
 	struct arphdr ar;
 	size_t len;
 	uint8_t *p;
+	const struct iarp_state *state;
 
 	ar.ar_hrd = htons(ifp->family);
 	ar.ar_pro = htons(ETHERTYPE_IP);
@@ -88,7 +89,9 @@ arp_request(const struct interface *ifp, in_addr_t sip, in_addr_t tip)
 	APPEND(&sip, sizeof(sip));
 	ZERO(ifp->hwlen);
 	APPEND(&tip, sizeof(tip));
-	return if_sendrawpacket(ifp, ETHERTYPE_ARP, arp_buffer, len);
+
+	state = ARP_CSTATE(ifp);
+	return if_sendraw(ifp, state->fd, ETHERTYPE_ARP, arp_buffer, len);
 
 eexit:
 	errno = ENOBUFS;
@@ -132,7 +135,7 @@ arp_packet(void *arg)
 	state = ARP_STATE(ifp);
 	flags = 0;
 	while (!(flags & RAW_EOF)) {
-		bytes = if_readrawpacket(ifp, ETHERTYPE_ARP,
+		bytes = if_readraw(ifp, state->fd,
 		    arp_buffer, sizeof(arp_buffer), &flags);
 		if (bytes == -1) {
 			logger(ifp->ctx, LOG_ERR,
@@ -200,7 +203,7 @@ arp_open(struct interface *ifp)
 
 	state = ARP_STATE(ifp);
 	if (state->fd == -1) {
-		state->fd = if_openrawsocket(ifp, ETHERTYPE_ARP);
+		state->fd = if_openraw(ifp, ETHERTYPE_ARP);
 		if (state->fd == -1) {
 			logger(ifp->ctx, LOG_ERR, "%s: %s: %m",
 			    __func__, ifp->name);
@@ -388,7 +391,7 @@ arp_free(struct arp_state *astate)
 		    TAILQ_FIRST(&state->arp_states) == NULL)
 		{
 			eloop_event_delete(ifp->ctx->eloop, state->fd);
-			close(state->fd);
+			if_closeraw(state->fd);
 			free(state);
 			ifp->if_data[IF_DATA_ARP] = NULL;
 		}
diff --git a/dhcp.c b/dhcp.c
index 2a87cfba..1ee273e3 100644
--- a/dhcp.c
+++ b/dhcp.c
@@ -1499,7 +1499,7 @@ dhcp_close(struct interface *ifp)
 
 	if (state->raw_fd != -1) {
 		eloop_event_delete(ifp->ctx->eloop, state->raw_fd);
-		close(state->raw_fd);
+		if_closeraw(state->raw_fd);
 		state->raw_fd = -1;
 	}
 
@@ -1727,12 +1727,12 @@ send_message(struct interface *ifp, uint8_t type,
 		size_t ulen;
 
 		r = 0;
-		udp = dhcp_makeudppacket(&ulen, (uint8_t *)bootp, len, from, to);
+		udp = dhcp_makeudppacket(&ulen, (uint8_t *)bootp, len, from,to);
 		if (udp == NULL) {
 			logger(ifp->ctx, LOG_ERR, "dhcp_makeudppacket: %m");
 		} else {
-			r = if_sendrawpacket(ifp, ETHERTYPE_IP,
-			    (uint8_t *)udp, ulen);
+			r = if_sendraw(ifp, state->raw_fd,
+			    ETHERTYPE_IP, (uint8_t *)udp, ulen);
 			free(udp);
 		}
 		/* If we failed to send a raw packet this normally means
@@ -1742,7 +1742,7 @@ send_message(struct interface *ifp, uint8_t type,
 		 * stopping the interface. */
 		if (r == -1) {
 			logger(ifp->ctx, LOG_ERR,
-			    "%s: if_sendrawpacket: %m", ifp->name);
+			    "%s: if_sendraw: %m", ifp->name);
 			switch(errno) {
 			case ENETDOWN:
 			case ENETRESET:
@@ -3101,7 +3101,7 @@ dhcp_handlepacket(void *arg)
 	flags = 0;
 	bootp = NULL;
 	while (!(flags & RAW_EOF)) {
-		bytes = (size_t)if_readrawpacket(ifp, ETHERTYPE_IP,
+		bytes = (size_t)if_readraw(ifp, state->raw_fd,
 		    buf, sizeof(buf), &flags);
 		if ((ssize_t)bytes == -1) {
 			logger(ifp->ctx, LOG_ERR,
@@ -3190,7 +3190,7 @@ dhcp_open(struct interface *ifp)
 
 	state = D_STATE(ifp);
 	if (state->raw_fd == -1) {
-		state->raw_fd = if_openrawsocket(ifp, ETHERTYPE_IP);
+		state->raw_fd = if_openraw(ifp, ETHERTYPE_IP);
 		if (state->raw_fd == -1) {
 			if (errno == ENOENT) {
 				logger(ifp->ctx, LOG_ERR,
diff --git a/if-bsd.c b/if-bsd.c
index dd033f67..57e315ff 100644
--- a/if-bsd.c
+++ b/if-bsd.c
@@ -359,8 +359,15 @@ if_findsa(struct dhcpcd_ctx *ctx, const struct sockaddr *sa)
 #ifdef INET
 const char *if_pfname = "Berkley Packet Filter";
 
+void
+if_closeraw(int fd)
+{
+
+	close(fd);
+}
+
 int
-if_openrawsocket(struct interface *ifp, uint16_t protocol)
+if_openraw(struct interface *ifp, uint16_t protocol)
 {
 	struct ipv4_state *state;
 	int fd = -1;
@@ -462,12 +469,11 @@ eexit:
 }
 
 ssize_t
-if_sendrawpacket(const struct interface *ifp, uint16_t protocol,
+if_sendraw(__unused const struct interface *ifp, int fd, uint16_t protocol,
     const void *data, size_t len)
 {
 	struct iovec iov[2];
 	struct ether_header hw;
-	int fd;
 
 	memset(&hw, 0, ETHER_HDR_LEN);
 	memset(&hw.ether_dhost, 0xff, ETHER_ADDR_LEN);
@@ -476,25 +482,20 @@ if_sendrawpacket(const struct interface *ifp, uint16_t protocol,
 	iov[0].iov_len = ETHER_HDR_LEN;
 	iov[1].iov_base = UNCONST(data);
 	iov[1].iov_len = len;
-	fd = ipv4_protocol_fd(ifp, protocol);
 	return writev(fd, iov, 2);
 }
 
 /* BPF requires that we read the entire buffer.
  * So we pass the buffer in the API so we can loop on >1 packet. */
 ssize_t
-if_readrawpacket(struct interface *ifp, uint16_t protocol,
-    void *data, size_t len, int *flags)
+if_readraw(struct interface *ifp, int fd, void *data, size_t len, int *flags)
 {
-	int fd;
 	struct bpf_hdr packet;
 	ssize_t bytes;
 	const unsigned char *payload;
 	struct ipv4_state *state;
 
 	state = IPV4_STATE(ifp);
-	fd = ipv4_protocol_fd(ifp, protocol);
-
 	*flags = 0;
 	for (;;) {
 		if (state->buffer_len == 0) {
diff --git a/if-linux.c b/if-linux.c
index 3cadbe88..2b094a32 100644
--- a/if-linux.c
+++ b/if-linux.c
@@ -1218,8 +1218,15 @@ struct nlmr
 #ifdef INET
 const char *if_pfname = "Packet Socket";
 
+void
+if_closeraw(int fd)
+{
+
+	close(fd);
+}
+
 int
-if_openrawsocket(struct interface *ifp, uint16_t protocol)
+if_openraw(struct interface *ifp, uint16_t protocol)
 {
 	int s;
 	union sockunion {
@@ -1270,7 +1277,7 @@ eexit:
 }
 
 ssize_t
-if_sendrawpacket(const struct interface *ifp, uint16_t protocol,
+if_sendraw(const struct interface *ifp, int fd, uint16_t protocol,
     const void *data, size_t len)
 {
 	union sockunion {
@@ -1278,7 +1285,6 @@ if_sendrawpacket(const struct interface *ifp, uint16_t protocol,
 		struct sockaddr_ll sll;
 		struct sockaddr_storage ss;
 	} su;
-	int fd;
 
 	memset(&su, 0, sizeof(su));
 	su.sll.sll_family = AF_PACKET;
@@ -1296,13 +1302,12 @@ if_sendrawpacket(const struct interface *ifp, uint16_t protocol,
 		    &ipv4_bcast_addr, sizeof(ipv4_bcast_addr));
 	} else
 		memset(&su.sll.sll_addr, 0xff, ifp->hwlen);
-	fd = ipv4_protocol_fd(ifp, protocol);
 
 	return sendto(fd, data, len, 0, &su.sa, sizeof(su.sll));
 }
 
 ssize_t
-if_readrawpacket(struct interface *ifp, uint16_t protocol,
+if_readraw(__unused struct interface *ifp, int fd,
     void *data, size_t len, int *flags)
 {
 	struct iovec iov = {
@@ -1320,14 +1325,12 @@ if_readrawpacket(struct interface *ifp, uint16_t protocol,
 #endif
 
 	ssize_t bytes;
-	int fd = -1;
 
 #ifdef PACKET_AUXDATA
 	msg.msg_control = cmsgbuf;
 	msg.msg_controllen = sizeof(cmsgbuf);
 #endif
 
-	fd = ipv4_protocol_fd(ifp, protocol);
 	bytes = recvmsg(fd, &msg, 0);
 	if (bytes == -1)
 		return -1;
diff --git a/if-sun.c b/if-sun.c
index 152fe284..f66d8479 100644
--- a/if-sun.c
+++ b/if-sun.c
@@ -351,8 +351,15 @@ out:
 #ifdef INET
 const char *if_pfname = "SunOS";
 
+void
+if_closeraw(int fd)
+{
+
+	UNUSED(fd);
+}
+
 int
-if_openrawsocket(struct interface *ifp, uint16_t protocol)
+if_openraw(struct interface *ifp, uint16_t protocol)
 {
 
 	UNUSED(ifp);
@@ -362,11 +369,12 @@ if_openrawsocket(struct interface *ifp, uint16_t protocol)
 }
 
 ssize_t
-if_sendrawpacket(const struct interface *ifp, uint16_t protocol,
+if_sendraw(const struct interface *ifp, int fd, uint16_t protocol,
     const void *data, size_t len)
 {
 
 	UNUSED(ifp);
+	UNUSED(fd);
 	UNUSED(protocol);
 	UNUSED(data);
 	UNUSED(len);
@@ -375,12 +383,12 @@ if_sendrawpacket(const struct interface *ifp, uint16_t protocol,
 }
 
 ssize_t
-if_readrawpacket(struct interface *ifp, uint16_t protocol,
+if_readraw(struct interface *ifp, int fd,
     void *data, size_t len, int *flags)
 {
 
 	UNUSED(ifp);
-	UNUSED(protocol);
+	UNUSED(fd);
 	UNUSED(data);
 	UNUSED(len);
 	UNUSED(flags);
diff --git a/if.h b/if.h
index de9b2d9f..3d997291 100644
--- a/if.h
+++ b/if.h
@@ -139,10 +139,11 @@ int if_managelink(struct dhcpcd_ctx *);
 
 #ifdef INET
 extern const char *if_pfname;
-int if_openrawsocket(struct interface *, uint16_t);
-ssize_t if_sendrawpacket(const struct interface *,
-    uint16_t, const void *, size_t);
-ssize_t if_readrawpacket(struct interface *, uint16_t, void *, size_t, int *);
+int if_openraw(struct interface *, uint16_t);
+ssize_t if_sendraw(const struct interface *, int, uint16_t,
+    const void *, size_t);
+ssize_t if_readraw(struct interface *, int, void *, size_t, int *);
+void if_closeraw(int);
 
 int if_address(const struct interface *,
     const struct in_addr *, const struct in_addr *,
diff --git a/ipv4.c b/ipv4.c
index 8bce2123..09e94c99 100644
--- a/ipv4.c
+++ b/ipv4.c
@@ -278,25 +278,6 @@ ipv4_init(struct dhcpcd_ctx *ctx)
 	return 0;
 }
 
-int
-ipv4_protocol_fd(const struct interface *ifp, uint16_t protocol)
-{
-
-	if (protocol == ETHERTYPE_ARP) {
-		const struct iarp_state *istate;
-
-		istate = ARP_CSTATE(ifp);
-		assert(istate != NULL);
-		return istate->fd;
-	} else {
-		const struct dhcp_state *dstate;
-
-		dstate = D_CSTATE(ifp);
-		assert(dstate != NULL);
-		return dstate->raw_fd;
-	}
-}
-
 /* Interface comparer for working out ordering. */
 int
 ipv4_ifcmp(const struct interface *si, const struct interface *ti)
diff --git a/ipv4.h b/ipv4.h
index 036b5bfc..cf8941da 100644
--- a/ipv4.h
+++ b/ipv4.h
@@ -97,7 +97,6 @@ struct ipv4_state {
 #ifdef INET
 struct ipv4_state *ipv4_getstate(struct interface *);
 int ipv4_init(struct dhcpcd_ctx *);
-int ipv4_protocol_fd(const struct interface *, uint16_t);
 int ipv4_ifcmp(const struct interface *, const struct interface *);
 uint8_t inet_ntocidr(struct in_addr);
 int inet_cidrtoaddr(int, struct in_addr *);