Index: head/stand/libsa/arp.c
===================================================================
--- head/stand/libsa/arp.c
+++ head/stand/libsa/arp.c
@@ -65,7 +65,7 @@
 
 /* Local forwards */
 static	ssize_t arpsend(struct iodesc *, void *, size_t);
-static	ssize_t arprecv(struct iodesc *, void **, void **, time_t);
+static	ssize_t arprecv(struct iodesc *, void **, void **, time_t, void *);
 
 /* Broadcast an ARP packet, asking who has addr on interface d */
 u_char *
@@ -118,7 +118,7 @@
 	ah = NULL;
 	i = sendrecv(d,
 	    arpsend, &wbuf.data, sizeof(wbuf.data),
-	    arprecv, &pkt, (void **)&ah);
+	    arprecv, &pkt, (void **)&ah, NULL);
 	if (i == -1) {
 		panic("arp: no response for %s\n",
 			  inet_ntoa(addr));
@@ -160,7 +160,7 @@
  * else -1 (and errno == 0)
  */
 static ssize_t
-arprecv(struct iodesc *d, void **pkt, void **payload, time_t tleft)
+arprecv(struct iodesc *d, void **pkt, void **payload, time_t tleft, void *extra)
 {
 	ssize_t n;
 	struct ether_arp *ah;
Index: head/stand/libsa/bootp.c
===================================================================
--- head/stand/libsa/bootp.c
+++ head/stand/libsa/bootp.c
@@ -73,7 +73,7 @@
 
 /* Local forwards */
 static	ssize_t bootpsend(struct iodesc *, void *, size_t);
-static	ssize_t bootprecv(struct iodesc *, void **, void **, time_t);
+static	ssize_t bootprecv(struct iodesc *, void **, void **, time_t, void *);
 static	int vend_rfc1048(u_char *, u_int);
 #ifdef BOOTP_VEND_CMU
 static	void vend_cmu(u_char *);
@@ -183,7 +183,7 @@
 
 	if(sendrecv(d,
 		    bootpsend, bp, sizeof(*bp),
-		    bootprecv, &pkt, (void **)&rbootp) == -1) {
+		    bootprecv, &pkt, (void **)&rbootp, NULL) == -1) {
 	    printf("bootp: no reply\n");
 	    return;
 	}
@@ -209,7 +209,7 @@
 		free(pkt);
 		if(sendrecv(d,
 			    bootpsend, bp, sizeof(*bp),
-			    bootprecv, &pkt, (void **)&rbootp) == -1) {
+			    bootprecv, &pkt, (void **)&rbootp, NULL) == -1) {
 			printf("DHCPREQUEST failed\n");
 			return;
 		}
@@ -286,7 +286,8 @@
 }
 
 static ssize_t
-bootprecv(struct iodesc *d, void **pkt, void **payload, time_t tleft)
+bootprecv(struct iodesc *d, void **pkt, void **payload, time_t tleft,
+    void *extra)
 {
 	ssize_t n;
 	struct bootp *bp;
Index: head/stand/libsa/net.h
===================================================================
--- head/stand/libsa/net.h
+++ head/stand/libsa/net.h
@@ -115,8 +115,9 @@
 ssize_t	sendrecv(struct iodesc *,
 			ssize_t (*)(struct iodesc *, void *, size_t),
 			void *, size_t,
-			ssize_t (*)(struct iodesc *, void **, void **, time_t),
-			void **, void **);
+			ssize_t (*)(struct iodesc *, void **, void **, time_t,
+			    void *),
+			void **, void **, void *);
 
 /* bootp/DHCP */
 void	bootp(int);
Index: head/stand/libsa/net.c
===================================================================
--- head/stand/libsa/net.c
+++ head/stand/libsa/net.c
@@ -72,8 +72,8 @@
 sendrecv(struct iodesc *d,
     ssize_t (*sproc)(struct iodesc *, void *, size_t),
     void *sbuf, size_t ssize,
-    ssize_t (*rproc)(struct iodesc *, void **, void **, time_t),
-    void **pkt, void **payload)
+    ssize_t (*rproc)(struct iodesc *, void **, void **, time_t, void *),
+    void **pkt, void **payload, void *recv_extra)
 {
 	ssize_t cc;
 	time_t t, tmo, tlast;
@@ -116,7 +116,7 @@
 		}
 
 		/* Try to get a packet and process it. */
-		cc = (*rproc)(d, pkt, payload, tleft);
+		cc = (*rproc)(d, pkt, payload, tleft, recv_extra);
 		/* Return on data, EOF or real error. */
 		if (cc != -1 || (errno != 0 && errno != ETIMEDOUT))
 			return (cc);
Index: head/stand/libsa/rarp.c
===================================================================
--- head/stand/libsa/rarp.c
+++ head/stand/libsa/rarp.c
@@ -54,7 +54,7 @@
 
 
 static ssize_t rarpsend(struct iodesc *, void *, size_t);
-static ssize_t rarprecv(struct iodesc *, void **, void **, time_t);
+static ssize_t rarprecv(struct iodesc *, void **, void **, time_t, void *);
 
 /*
  * Ethernet (Reverse) Address Resolution Protocol (see RFC 903, and 826).
@@ -99,7 +99,7 @@
 
 	if (sendrecv(d,
 	    rarpsend, &wbuf.data, sizeof(wbuf.data),
-	    rarprecv, &pkt, (void *)&ap) < 0) {
+	    rarprecv, &pkt, (void *)&ap, NULL) < 0) {
 		printf("No response for RARP request\n");
 		return (-1);
 	}
@@ -143,7 +143,8 @@
  * else -1 (and errno == 0)
  */
 static ssize_t
-rarprecv(struct iodesc *d, void **pkt, void **payload, time_t tleft)
+rarprecv(struct iodesc *d, void **pkt, void **payload, time_t tleft,
+    void *extra)
 {
 	ssize_t n;
 	struct ether_arp *ap;
Index: head/stand/libsa/rpc.c
===================================================================
--- head/stand/libsa/rpc.c
+++ head/stand/libsa/rpc.c
@@ -97,7 +97,7 @@
 };
 
 /* Local forwards */
-static	ssize_t recvrpc(struct iodesc *, void **, void **, time_t);
+static	ssize_t recvrpc(struct iodesc *, void **, void **, time_t, void *);
 static	int rpc_getport(struct iodesc *, n_long, n_long);
 
 int rpc_xid;
@@ -167,7 +167,7 @@
 	ptr = NULL;
 	cc = sendrecv(d,
 	    sendudp, send_head, send_tail - send_head,
-	    recvrpc, &ptr, (void **)&reply);
+	    recvrpc, &ptr, (void **)&reply, NULL);
 
 #ifdef RPC_DEBUG
 	if (debug)
@@ -217,7 +217,7 @@
  * Remaining checks are done by callrpc
  */
 static ssize_t
-recvrpc(struct iodesc *d, void **pkt, void **payload, time_t tleft)
+recvrpc(struct iodesc *d, void **pkt, void **payload, time_t tleft, void *extra)
 {
 	void *ptr;
 	struct rpc_reply *reply;
Index: head/stand/libsa/tftp.c
===================================================================
--- head/stand/libsa/tftp.c
+++ head/stand/libsa/tftp.c
@@ -61,7 +61,10 @@
 #include "tftp.h"
 
 struct tftp_handle;
+struct tftprecv_extra;
 
+static ssize_t recvtftp(struct iodesc *d, void **pkt, void **payload,
+    time_t tleft, void *recv_extra);
 static int	tftp_open(const char *path, struct open_file *f);
 static int	tftp_close(struct open_file *f);
 static int	tftp_parse_oack(struct tftp_handle *h, char *buf, size_t len);
@@ -70,11 +73,6 @@
 static off_t	tftp_seek(struct open_file *f, off_t offset, int where);
 static int	tftp_set_blksize(struct tftp_handle *h, const char *str);
 static int	tftp_stat(struct open_file *f, struct stat *sb);
-static ssize_t sendrecv_tftp(struct tftp_handle *h,
-    ssize_t (*sproc)(struct iodesc *, void *, size_t),
-    void *sbuf, size_t ssize,
-    ssize_t (*rproc)(struct tftp_handle *h, void **, void **, time_t, unsigned short *),
-    void **, void **, unsigned short *rtype);
 
 struct fs_ops tftp_fsops = {
 	"tftp",
@@ -118,6 +116,11 @@
 	struct tftphdr	*tftp_hdr;
 };
 
+struct tftprecv_extra {
+	struct tftp_handle	*tftp_handle;
+	unsigned short		 rtype;		/* Received type */
+};
+
 #define	TFTP_MAX_ERRCODE EOPTNEG
 static const int tftperrors[TFTP_MAX_ERRCODE + 1] = {
 	0,			/* ??? */
@@ -178,15 +181,19 @@
 }
 
 static ssize_t
-recvtftp(struct tftp_handle *h, void **pkt, void **payload, time_t tleft,
-    unsigned short *rtype)
+recvtftp(struct iodesc *d, void **pkt, void **payload, time_t tleft,
+    void *recv_extra)
 {
-	struct iodesc *d = h->iodesc;
+	struct tftprecv_extra *extra;
+	struct tftp_handle *h;
 	struct tftphdr *t;
+	unsigned short *rtype;
 	void *ptr = NULL;
 	ssize_t len;
 
 	errno = 0;
+	extra = (struct tftprecv_extra *)recv_extra;
+	h = extra->tftp_handle;
 
 	len = readudp(d, &ptr, (void **)&t, tleft);
 
@@ -195,7 +202,7 @@
 		return (-1);
 	}
 
-	*rtype = ntohs(t->th_opcode);
+	extra->rtype = ntohs(t->th_opcode);
 	switch (ntohs(t->th_opcode)) {
 	case DATA: {
 		int got;
@@ -282,6 +289,7 @@
 		struct tftphdr  t;
 		u_char space[FNAME_SIZE + 6];
 	} __packed __aligned(4) wbuf;
+	struct tftprecv_extra recv_extra;
 	char           *wtail;
 	int             l;
 	ssize_t         res;
@@ -289,7 +297,6 @@
 	struct tftphdr *t;
 	char *tftp_blksize = NULL;
 	int blksize_l;
-	unsigned short rtype = 0;
 
 	/*
 	 * Allow overriding default TFTP block size by setting
@@ -334,8 +341,9 @@
 	h->validsize = 0;
 
 	pkt = NULL;
-	res = sendrecv_tftp(h, &sendudp, &wbuf.t, wtail - (char *) &wbuf.t,
-		       &recvtftp, &pkt, (void **)&t, &rtype);
+	recv_extra.tftp_handle = h;
+	res = sendrecv(h->iodesc, &sendudp, &wbuf.t, wtail - (char *) &wbuf.t,
+		       (void *)&recvtftp, &pkt, (void **)&t, &recv_extra);
 	if (res == -1) {
 		free(pkt);
 		return (errno);
@@ -345,13 +353,13 @@
 	h->pkt = pkt;
 	h->tftp_hdr = t;
 
-	if (rtype == OACK)
+	if (recv_extra.rtype == OACK)
 		return (tftp_getnextblock(h));
 
 	/* Server ignored our blksize request, revert to TFTP default. */
 	h->tftp_blksize = SEGSIZE;
 
-	switch (rtype) {
+	switch (recv_extra.rtype) {
 		case DATA: {
 			h->currblock = 1;
 			h->validsize = res;
@@ -377,11 +385,11 @@
 		u_char header[HEADER_SIZE];
 		struct tftphdr t;
 	} __packed __aligned(4) wbuf;
+	struct tftprecv_extra recv_extra;
 	char           *wtail;
 	int             res;
 	void *pkt;
 	struct tftphdr *t;
-	unsigned short rtype = 0;
 	wbuf.t.th_opcode = htons((u_short) ACK);
 	wtail = (char *) &wbuf.t.th_block;
 	wbuf.t.th_block = htons((u_short) h->currblock);
@@ -390,8 +398,9 @@
 	h->iodesc->xid = h->currblock + 1;	/* expected block */
 
 	pkt = NULL;
-	res = sendrecv_tftp(h, &sendudp, &wbuf.t, wtail - (char *) &wbuf.t,
-		       &recvtftp, &pkt, (void **)&t, &rtype);
+	recv_extra.tftp_handle = h;
+	res = sendrecv(h->iodesc, &sendudp, &wbuf.t, wtail - (char *) &wbuf.t,
+		       (void *)&recvtftp, &pkt, (void **)&t, &recv_extra);
 
 	if (res == -1) {		/* 0 is OK! */
 		free(pkt);
@@ -603,67 +612,6 @@
 		return (-1);
 	}
 	return (tftpfile->off);
-}
-
-static ssize_t
-sendrecv_tftp(struct tftp_handle *h,
-    ssize_t (*sproc)(struct iodesc *, void *, size_t),
-    void *sbuf, size_t ssize,
-    ssize_t (*rproc)(struct tftp_handle *, void **, void **, time_t,
-    unsigned short *),
-    void **pkt, void **payload, unsigned short *rtype)
-{
-	struct iodesc *d = h->iodesc;
-	ssize_t cc;
-	time_t t, t1, tleft;
-
-#ifdef TFTP_DEBUG
-	if (debug)
-		printf("sendrecv: called\n");
-#endif
-
-	tleft = MINTMO;
-	t = t1 = getsecs();
-	for (;;) {
-		if ((getsecs() - t) > MAXTMO) {
-			errno = ETIMEDOUT;
-			return -1;
-		}
-
-		cc = (*sproc)(d, sbuf, ssize);
-		if (cc != -1 && cc < ssize)
-			panic("sendrecv: short write! (%zd < %zu)",
-			    cc, ssize);
-
-		if (cc == -1) {
-			/* Error on transmit; wait before retrying */
-			while ((getsecs() - t1) < tleft);
-			t1 = getsecs();
-			continue;
-		}
-
-		t = t1 = getsecs();
-recvnext:
-		if ((getsecs() - t) > MAXTMO) {
-			errno = ETIMEDOUT;
-			return -1;
-		}
-		/* Try to get a packet and process it. */
-		cc = (*rproc)(h, pkt, payload, tleft, rtype);
-		/* Return on data, EOF or real error. */
-		if (cc != -1 || (errno != 0 && errno != ETIMEDOUT))
-			return (cc);
-		if ((getsecs() - t1) < tleft) {
-		    goto recvnext;
-		}
-
-		/* Timed out or didn't get the packet we're waiting for */
-		tleft += MINTMO;
-		if (tleft > (2 * MINTMO)) {
-			tleft = (2 * MINTMO);
-		}
-		t1 = getsecs();
-	}
 }
 
 static int