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Date:      Tue, 13 Jan 2009 22:46:24 +0000 (UTC)
From:      Luigi Rizzo <luigi@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-7@freebsd.org
Subject:   svn commit: r187200 - stable/7/lib/libstand
Message-ID:  <200901132246.n0DMkOUw018605@svn.freebsd.org>

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Author: luigi
Date: Tue Jan 13 22:46:24 2009
New Revision: 187200
URL: http://svn.freebsd.org/changeset/base/187200

Log:
  MFC from rev.185643 and 186799
  
  Some libstand/bootp.c extension (written by Danny Braniss, slightly
  revised/modified by me) to store dhcp options into kenv variables,
  so the information is available to the boot loader and can be used
  to customize the boot process.

Modified:
  stable/7/lib/libstand/bootp.c

Modified: stable/7/lib/libstand/bootp.c
==============================================================================
--- stable/7/lib/libstand/bootp.c	Tue Jan 13 22:35:26 2009	(r187199)
+++ stable/7/lib/libstand/bootp.c	Tue Jan 13 22:46:24 2009	(r187200)
@@ -47,6 +47,12 @@ __FBSDID("$FreeBSD$");
 #define BOOTP_DEBUGxx
 #define SUPPORT_DHCP
 
+#define	DHCP_ENV_NOVENDOR	1	/* do not parse vendor options */
+#define	DHCP_ENV_PXE		10	/* assume pxe vendor options */
+#define	DHCP_ENV_FREEBSD	11	/* assume freebsd vendor options
+/* set DHCP_ENV to one of the values above to export dhcp options to kenv */
+#define DHCP_ENV		DHCP_ENV_NO_VENDOR
+
 #include "stand.h"
 #include "net.h"
 #include "netif.h"
@@ -72,6 +78,13 @@ static	int vend_rfc1048(u_char *, u_int)
 static	void vend_cmu(u_char *);
 #endif
 
+#ifdef DHCP_ENV		/* export the dhcp response to kenv */
+struct dhcp_opt;
+static void setenv_(u_char *cp,  u_char *ep, struct dhcp_opt *opts);
+#else
+#define setenv_(a, b, c)
+#endif
+
 #ifdef SUPPORT_DHCP
 static char expected_dhcpmsgtype = -1, dhcp_ok;
 struct in_addr dhcp_serverip;
@@ -351,6 +364,8 @@ vend_rfc1048(cp, len)
 	/* Step over magic cookie */
 	cp += sizeof(int);
 
+	setenv_(cp, ep, NULL);
+
 	while (cp < ep) {
 		tag = *cp++;
 		size = *cp++;
@@ -412,3 +427,316 @@ vend_cmu(cp)
 	}
 }
 #endif
+
+#ifdef DHCP_ENV
+/*
+ * Parse DHCP options and store them into kenv variables.
+ * Original code from Danny Braniss, modifications by Luigi Rizzo.
+ *
+ * The parser is driven by tables which specify the type and name of
+ * each dhcp option and how it appears in kenv.
+ * The first entry in the list contains the prefix used to set the kenv
+ * name (including the . if needed), the last entry must have a 0 tag.
+ * Entries do not need to be sorted though it helps for readability.
+ *
+ * Certain vendor-specific tables can be enabled according to DHCP_ENV.
+ * Set it to 0 if you don't want any.
+ */
+enum opt_fmt { __NONE = 0,
+	__8 = 1, __16 = 2, __32 = 4,	/* Unsigned fields, value=size	*/
+	__IP,				/* IPv4 address			*/
+	__TXT,				/* C string			*/
+	__BYTES,			/* byte sequence, printed %02x	*/
+	__INDIR,			/* name=value			*/
+	__ILIST,			/* name=value;name=value ... */
+	__VE,				/* vendor specific, recurse	*/
+};
+
+struct dhcp_opt {
+	uint8_t	tag;
+	uint8_t	fmt;
+	const char	*desc;
+};
+
+static struct dhcp_opt vndr_opt[] = { /* Vendor Specific Options */
+#if DHCP_ENV == DHCP_ENV_FREEBSD /* FreeBSD table in the original code */
+	{0,	0,	"FreeBSD"},		/* prefix */
+	{1,	__TXT,	"kernel"},
+	{2,	__TXT,	"kernelname"},
+	{3,	__TXT,	"kernel_options"},
+	{4,	__IP,	"usr-ip"},
+	{5,	__TXT,	"conf-path"},
+	{6,	__TXT,	"rc.conf0"},
+	{7,	__TXT,	"rc.conf1"},
+	{8,	__TXT,	"rc.conf2"},
+	{9,	__TXT,	"rc.conf3"},
+	{10,	__TXT,	"rc.conf4"},
+	{11,	__TXT,	"rc.conf5"},
+	{12,	__TXT,	"rc.conf6"},
+	{13,	__TXT,	"rc.conf7"},
+	{14,	__TXT,	"rc.conf8"},
+	{15,	__TXT,	"rc.conf9"},
+
+	{20,	__TXT,  "boot.nfsroot.options"},
+
+	{245,	__INDIR, ""},
+	{246,	__INDIR, ""},
+	{247,	__INDIR, ""},
+	{248,	__INDIR, ""},
+	{249,	__INDIR, ""},
+	{250,	__INDIR, ""},
+	{251,	__INDIR, ""},
+	{252,	__INDIR, ""},
+	{253,	__INDIR, ""},
+	{254,	__INDIR, ""},
+
+#elif DHCP_ENV == DHCP_ENV_PXE		/* some pxe options, RFC4578 */
+	{0,	0,	"pxe"},		/* prefix */
+	{93,	__16,	"system-architecture"},
+	{94,	__BYTES,	"network-interface"},
+	{97,	__BYTES,	"machine-identifier"},
+#else					/* default (empty) table */
+	{0,	0,	"dhcp.vendor."},		/* prefix */
+#endif
+	{0,	__TXT,	"%soption-%d"}
+};
+
+static struct dhcp_opt dhcp_opt[] = {
+	/* DHCP Option names, formats and codes, from RFC2132. */
+	{0,	0,	"dhcp."},	// prefix
+	{1,	__IP,	"subnet-mask"},
+	{2,	__32,	"time-offset"}, /* this is signed */
+	{3,	__IP,	"routers"},
+	{4,	__IP,	"time-servers"},
+	{5,	__IP,	"ien116-name-servers"},
+	{6,	__IP,	"domain-name-servers"},
+	{7,	__IP,	"log-servers"},
+	{8,	__IP,	"cookie-servers"},
+	{9,	__IP,	"lpr-servers"},
+	{10,	__IP,	"impress-servers"},
+	{11,	__IP,	"resource-location-servers"},
+	{12,	__TXT,	"host-name"},
+	{13,	__16,	"boot-size"},
+	{14,	__TXT,	"merit-dump"},
+	{15,	__TXT,	"domain-name"},
+	{16,	__IP,	"swap-server"},
+	{17,	__TXT,	"root-path"},
+	{18,	__TXT,	"extensions-path"},
+	{19,	__8,	"ip-forwarding"},
+	{20,	__8,	"non-local-source-routing"},
+	{21,	__IP,	"policy-filter"},
+	{22,	__16,	"max-dgram-reassembly"},
+	{23,	__8,	"default-ip-ttl"},
+	{24,	__32,	"path-mtu-aging-timeout"},
+	{25,	__16,	"path-mtu-plateau-table"},
+	{26,	__16,	"interface-mtu"},
+	{27,	__8,	"all-subnets-local"},
+	{28,	__IP,	"broadcast-address"},
+	{29,	__8,	"perform-mask-discovery"},
+	{30,	__8,	"mask-supplier"},
+	{31,	__8,	"perform-router-discovery"},
+	{32,	__IP,	"router-solicitation-address"},
+	{33,	__IP,	"static-routes"},
+	{34,	__8,	"trailer-encapsulation"},
+	{35,	__32,	"arp-cache-timeout"},
+	{36,	__8,	"ieee802-3-encapsulation"},
+	{37,	__8,	"default-tcp-ttl"},
+	{38,	__32,	"tcp-keepalive-interval"},
+	{39,	__8,	"tcp-keepalive-garbage"},
+	{40,	__TXT,	"nis-domain"},
+	{41,	__IP,	"nis-servers"},
+	{42,	__IP,	"ntp-servers"},
+	{43,	__VE,	"vendor-encapsulated-options"},
+	{44,	__IP,	"netbios-name-servers"},
+	{45,	__IP,	"netbios-dd-server"},
+	{46,	__8,	"netbios-node-type"},
+	{47,	__TXT,	"netbios-scope"},
+	{48,	__IP,	"x-font-servers"},
+	{49,	__IP,	"x-display-managers"},
+	{50,	__IP,	"dhcp-requested-address"},
+	{51,	__32,	"dhcp-lease-time"},
+	{52,	__8,	"dhcp-option-overload"},
+	{53,	__8,	"dhcp-message-type"},
+	{54,	__IP,	"dhcp-server-identifier"},
+	{55,	__8,	"dhcp-parameter-request-list"},
+	{56,	__TXT,	"dhcp-message"},
+	{57,	__16,	"dhcp-max-message-size"},
+	{58,	__32,	"dhcp-renewal-time"},
+	{59,	__32,	"dhcp-rebinding-time"},
+	{60,	__TXT,	"vendor-class-identifier"},
+	{61,	__TXT,	"dhcp-client-identifier"},
+	{64,	__TXT,	"nisplus-domain"},
+	{65,	__IP,	"nisplus-servers"},
+	{66,	__TXT,	"tftp-server-name"},
+	{67,	__TXT,	"bootfile-name"},
+	{68,	__IP,	"mobile-ip-home-agent"},
+	{69,	__IP,	"smtp-server"},
+	{70,	__IP,	"pop-server"},
+	{71,	__IP,	"nntp-server"},
+	{72,	__IP,	"www-server"},
+	{73,	__IP,	"finger-server"},
+	{74,	__IP,	"irc-server"},
+	{75,	__IP,	"streettalk-server"},
+	{76,	__IP,	"streettalk-directory-assistance-server"},
+	{77,	__TXT,	"user-class"},
+	{85,	__IP,	"nds-servers"},
+	{86,	__TXT,	"nds-tree-name"},
+	{87,	__TXT,	"nds-context"},
+	{210,	__TXT,	"authenticate"},
+
+	/* use the following entries for arbitrary variables */
+	{246,	__ILIST, ""},
+	{247,	__ILIST, ""},
+	{248,	__ILIST, ""},
+	{249,	__ILIST, ""},
+	{250,	__INDIR, ""},
+	{251,	__INDIR, ""},
+	{252,	__INDIR, ""},
+	{253,	__INDIR, ""},
+	{254,	__INDIR, ""},
+	{0,	__TXT,	"%soption-%d"}
+};
+
+/*
+ * parse a dhcp response, set environment variables translating options
+ * names and values according to the tables above. Also set dhcp.tags
+ * to the list of selected tags.
+ */
+static void
+setenv_(u_char *cp,  u_char *ep, struct dhcp_opt *opts)
+{
+    u_char	*ncp;
+    u_char	tag;
+    char	tags[512], *tp;	/* the list of tags */
+
+#define FLD_SEP	','	/* separator in list of elements */
+    ncp = cp;
+    tp = tags;
+    if (opts == NULL)
+	opts = dhcp_opt;
+
+    while (ncp < ep) {
+	unsigned int	size;		/* option size */
+	char *vp, *endv, buf[256];	/* the value buffer */
+	struct dhcp_opt *op;
+
+	tag = *ncp++;			/* extract tag and size */
+	size = *ncp++;
+	cp = ncp;			/* current payload */
+	ncp += size;			/* point to the next option */
+
+	if (tag == TAG_END)
+	    break;
+	if (tag == 0)
+	    continue;
+
+	for (op = opts+1; op->tag && op->tag != tag; op++)
+		;
+	/* if not found we end up on the default entry */
+
+	/*
+	 * Copy data into the buffer. libstand does not have snprintf so we
+	 * need to be careful with sprintf(). With strings, the source is
+	 * always <256 char so shorter than the buffer so we are safe; with
+	 * other arguments, the longest string is inet_ntoa which is 16 bytes
+	 * so we make sure to have always enough room in the string before
+	 * trying an sprint.
+	 */
+	vp = buf;
+	*vp = '\0';
+	endv = buf + sizeof(buf) - 1 - 16;	/* last valid write position */
+
+	switch(op->fmt) {
+	case __NONE:
+	    break;	/* should not happen */
+
+	case __VE: /* recurse, vendor specific */
+	    setenv_(cp, cp+size, vndr_opt);
+	    break;
+
+	case __IP:	/* ip address */
+	    for (; size > 0 && vp < endv; size -= 4, cp += 4) {
+		struct	in_addr in_ip;		/* ip addresses */
+		if (vp != buf)
+		    *vp++ = FLD_SEP;
+		bcopy(cp, &in_ip.s_addr, sizeof(in_ip.s_addr));
+		sprintf(vp, "%s", inet_ntoa(in_ip));
+		vp += strlen(vp);
+	    }
+	    break;
+
+	case __BYTES:	/* opaque byte string */
+	    for (; size > 0 && vp < endv; size -= 1, cp += 1) {
+		sprintf(vp, "%02x", *cp);
+		vp += strlen(vp);
+	    }
+	    break;
+
+	case __TXT:
+	    bcopy(cp, buf, size);	/* cannot overflow */
+	    buf[size] = 0;
+	    break;
+
+	case __32:
+	case __16:
+	case __8:	/* op->fmt is also the length of each field */
+	    for (; size > 0 && vp < endv; size -= op->fmt, cp += op->fmt) {
+		uint32_t v;
+		if (op->fmt == __32)
+			v = (cp[0]<<24) + (cp[1]<<16) + (cp[2]<<8) + cp[3];
+		else if (op->fmt == __16)
+			v = (cp[0]<<8) + cp[1];
+		else
+			v = cp[0];
+		if (vp != buf)
+		    *vp++ = FLD_SEP;
+		sprintf(vp, "%u", v);
+		vp += strlen(vp);
+	    }
+	    break;
+
+	case __INDIR:	/* name=value */
+	case __ILIST:	/* name=value;name=value... */
+	    bcopy(cp, buf, size);	/* cannot overflow */
+	    buf[size] = '\0';
+	    for (endv = buf; endv; endv = vp) {
+		u_char *s = NULL;	/* semicolon ? */
+
+		/* skip leading whitespace */
+		while (*endv && index(" \t\n\r", *endv))
+		    endv++;
+		vp = index(endv, '=');	/* find name=value separator */
+		if (!vp)
+		    break;
+		*vp++ = 0;
+		if (op->fmt == __ILIST && (s = index(vp, ';')))
+		    *s++ = '\0';
+		setenv(endv, vp, 1);
+		vp = s;	/* prepare for next round */
+	    }
+	    buf[0] = '\0';	/* option already done */
+	}
+
+	if (tp - tags < sizeof(tags) - 5) {	/* add tag to the list */
+	    if (tp != tags)
+		*tp++ = FLD_SEP;
+	    sprintf(tp, "%d", tag);
+	    tp += strlen(tp);
+	}
+	if (buf[0]) {
+	    char	env[128];	/* the string name */
+
+	    if (op->tag == 0)
+		sprintf(env, op->desc, opts[0].desc, tag);
+	    else
+		sprintf(env, "%s%s", opts[0].desc, op->desc);
+	    setenv(env, buf, 1);
+	}
+    }
+    if (tp != tags) {
+	char	env[128];	/* the string name */
+	sprintf(env, "%stags", opts[0].desc);
+	setenv(env, tags, 1);
+    }
+}
+#endif /* additional dhcp */



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