shithub: catphone

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got referential REGISTER procedure working.

--- /dev/null

+++ b/catphone.man

@@ -1,0 +1,33 @@

+.TH MUSW 1

+.SH NAME

+catphone \- VoIP softphone worth a cat

+.SH SYNOPSIS

+.B catphone

+[

+.B -d

+]

+.I dialstring

+.I user

+.I password

+.SH DESCRIPTION

+.I Catphone

+is a VoIP softphone operated by a cat.

+.SH EXAMPLE

+.IP

+.EX

+% catphone udp!pbx.only9fans.com!sip bob secretodebob

+.EE

+.SH SOURCE

+.B /sys/src/cmd/catphone

+.SH SEE ALSO

+.IR catclock (1)

+.br

+/lib/rfc/rfc3261

+.br

+/lib/rfc/rfc8760

+.br

+Gonzalo Camarillo, “SIP Demystified”, McGraw-Hill, 2001.

+.SH BUGS

+.SH HISTORY

+.I Catphone

+first appeared in 9front (August, 2023).

--- a/dat.h

+++ b/dat.h

@@ -13,6 +13,10 @@

 	REFER

 } SipMethod;

+typedef enum {

+	AMD5,

+} SipAuthAlgo;

+

 /* rfc3261 § 21 - Response Codes */

 typedef enum {

 	/* 1xx Provisional */

@@ -99,8 +103,25 @@

 struct Sipmsg

 {

 	Hdrtab;

-	char *version;

+

+	struct {

+		char *algo;

+		char *realm;

+		char *nonce;

+		char *response;

+	} auth;

+

+	/* request */

 	SipMethod method;

+	char *uri;

+

+	/* response */

+	int code;

+	char *reason;

+

+	char *version;

+	ulong len;

+	char body[];

 };

 /* SIP UAC (see rfc3261 § 8.1, 12.1.2) */

@@ -113,5 +134,7 @@

 	int (*reg)(Sip*, char*, char*);

 };

+

+#pragma varargck type "S" Sipmsg*

 extern int debug;

--- a/fns.h

+++ b/fns.h

@@ -2,9 +2,16 @@

 void *erealloc(void*, ulong);

 Image *eallocimage(Display*, Rectangle, ulong, int, ulong);

+int Sfmt(Fmt*);

+void SIPfmtinstall(void);

+

 void addheader(Hdrtab*, char*, char*);

 Hdr *getheader(Hdrtab*, char*);

 void delheader(Hdrtab*, char*);

+void delheaders(Hdrtab*);

+

+Sipmsg *newsipmsg(void);

+void delsipmsg(Sipmsg*);

 Sip *mksip(int);

 void rmsip(Sip*);

--- a/main.c

+++ b/main.c

@@ -22,6 +22,7 @@

 	char *addr;

 	int fd;

+	SIPfmtinstall();

 	ARGBEGIN{

 	default: usage();

 	case 'd':

--- a/sip.c

+++ b/sip.c

@@ -1,11 +1,14 @@

 #include <u.h>

 #include <libc.h>

 #include <bio.h>

+#include <mp.h>

+#include <libsec.h>

 #include <draw.h>

 #include "dat.h"

 #include "fns.h"

 static char sipversion[] = "SIP/2.0";

+static char useragent[] = "catphone (plan9front)";

 static char *methodstrtab[] = {

  [REGISTER]	"REGISTER",

  [INVITE]	"INVITE",

@@ -21,18 +24,6 @@

  [REFER]	"REFER",

 };

-static char registerhdr0[] = "REGISTER sip:%s %s\r\n"

-	"Via: %s/UDP %s:%s;branch=z9hG4bK703d971c0c737b8e;rport\r\n"

-	"Contact: <sip:%s-0x82a66a010@%s:%s>;expires=3849\r\n"

-	"Max-Forwards: 70\r\n"

-	"To: <sip:%s@%s>\r\n"

-	"From: <sip:%s@%s>;tag=4a5a693256d38cbc\r\n"

-	"Call-ID: 2cee372fc4be4e45\r\n"

-	"CSeq: 16021 REGISTER\r\n"

-	"User-Agent: catphone (plan9front)\r\n"

-	"Allow: INVITE,ACK,BYE,CANCEL,OPTIONS,NOTIFY,SUBSCRIBE,INFO,MESSAGE,UPDATE,REFER\r\n"

-	"Content-Length: 0\r\n"

-	"\r\n";

 static char registerhdr[] = "REGISTER sip:10.0.0.104 SIP/2.0\r\n"

 	"Via: SIP/2.0/UDP 10.0.1.9:54022;branch=z9hG4bKdf800c31b9a88ffb;rport\r\n"

 	"Contact: <sip:sam-0x82a66a010@10.0.1.9:54022>;expires=3849\r\n"

@@ -47,6 +38,13 @@

 	"Content-Length: 0\r\n"

 	"\r\n";

+static void

+strtolower(char *s)

+{

+	while(*s)

+		*s++ = tolower(*s);

+}

+

 static char *

 getmethodstr(SipMethod m)

 {

@@ -53,6 +51,52 @@

 	return methodstrtab[m];

 }

+static char *

+md5authfn(char *user, char *pass, char *uri, Sipmsg* m)

+{

+	uchar h1d[MD5dlen], h2d[MD5dlen], rd[MD5dlen];

+	char h1ds[2*MD5dlen+1], h2ds[2*MD5dlen+1];

+	static char rds[2*MD5dlen+1];

+	char buf[4096];

+

+	snprint(buf, sizeof buf, "%s:%s:%s", user, m->auth.realm, pass);

+	if(debug)

+		fprint(2, "h1: %s\n", buf);

+	md5((uchar*)buf, strlen(buf), h1d, nil);

+	snprint(buf, sizeof buf, "%s:%s", getmethodstr(m->method), uri);

+	if(debug)

+		fprint(2, "h2: %s\n", buf);

+	md5((uchar*)buf, strlen(buf), h2d, nil);

+	

+	enc16(h1ds, sizeof h1ds, h1d, sizeof h1d);

+	enc16(h2ds, sizeof h2ds, h2d, sizeof h2d);

+	h1ds[nelem(h1ds)-1] = 0;

+	h2ds[nelem(h2ds)-1] = 0;

+	strtolower(h1ds);

+	strtolower(h2ds);

+	if(debug)

+		fprint(2, "h1ds: %s\nh2ds: %s\n", h1ds, h2ds);

+

+	snprint(buf, sizeof buf, "%s:%s:%s", h1ds, m->auth.nonce, h2ds);

+	if(debug)

+		fprint(2, "r: %s\n", buf);

+	md5((uchar*)buf, strlen(buf), rd, nil);

+	enc16(rds, sizeof rds, rd, sizeof rd);

+	rds[nelem(rds)-1] = 0;

+	strtolower(rds);

+	if(debug)

+		fprint(2, "rds: %s\n", rds);

+

+	return rds;

+}

+

+static struct {

+	char *name;

+	char *(*fn)(char*, char*, char*, Sipmsg*);

+} algos[] = {

+ [AMD5]	{ .name = "MD5", .fn = md5authfn },

+};

+

 static uint

 hash(char *s)

 {

@@ -64,7 +108,215 @@

 	return h % 13;

 }

+/* rfc3261 § 10 - Registrations */

+static int

+sip_register(Sip *s, char *user, char *pass)

+{

+	Sipmsg *req, *res;

+	Hdr *h;

+	Biobuf *bin, *bout;

+	char *line, *p, *kv[8], *kv2[2], buf[1024];

+	int n;

+

+	if((bin = Bfdopen(s->fd, OREAD)) == nil)

+		sysfatal("Bfdopen: %r");

+	if((bout = Bfdopen(s->fd, OWRITE)) == nil)

+		sysfatal("Bfdopen: %r");

+

+	/* present yourself */

+	req = newsipmsg();

+	req->method = REGISTER;

+	req->uri = smprint("sip:%s", s->nci->rsys);

+	req->version = sipversion;

+	snprint(buf, sizeof buf, "%s/UDP %s:%s;branch=z9hG4bK703d971c0c737b8e;rport",

+		sipversion, s->nci->lsys, s->nci->lserv);

+	addheader(req, "Via", buf);

+	snprint(buf, sizeof buf, "<sip:%s-0x82a66a010@%s:%s>;expires=3849",

+		user, s->nci->lsys, s->nci->lserv);

+	addheader(req, "Contact", buf);

+	addheader(req, "Max-Forwards", "70");

+	snprint(buf, sizeof buf, "<sip:%s@%s>",

+		user, s->nci->rsys);

+	addheader(req, "To", buf);

+	snprint(buf, sizeof buf, "<sip:%s@%s>;tag=4a5a693256d38cbc",

+		user, s->nci->rsys);

+	addheader(req, "From", buf);

+	addheader(req, "Call-ID", "2cee372fc4be4e45");

+	addheader(req, "CSeq", "16021 REGISTER");

+	addheader(req, "User-Agent", useragent);

+	addheader(req, "Allow", "INVITE,ACK,BYE,CANCEL,OPTIONS,NOTIFY,SUBSCRIBE,INFO,MESSAGE,UPDATE,REFER");

+	snprint(buf, sizeof buf, "%lud", req->len);

+	addheader(req, "Content-Length", buf);

+

+	Bprint(bout, "%S", req);

+	Bflush(bout);

+

+	if(debug)

+		fprint(2, "sent:\n%S\n", req);

+

+	delsipmsg(req);

+

+	/* wait for the challenge */

+	res = newsipmsg();

+	while((line = Brdline(bin, '\n')) != nil){

+		if(strncmp(line, "\r\n", 2) == 0)

+			break;

+

+		p = strchr(line, '\r');

+		*p++ = 0, *p = 0;

+

+		if(strstr(line, ":") == nil && req->code == 0){

+			if(gettokens(line, kv, 3, " ") == 3){

+				res->version = strdup(kv[0]);

+				res->code = strtoul(kv[1], nil, 10);

+				res->reason = strdup(kv[2]);

+			}

+			continue;

+		}

+

+		if(gettokens(line, kv, 2, ": ") == 2)

+			addheader(res, kv[0], kv[1]);

+	}

+

+	if(debug)

+		fprint(2, "rcvd:\n%S\n", res);

+

+	/* respond to the challenge */

+	if((h = getheader(res, "WWW-Authenticate")) == nil)

+		return -1;

+

+	if((n = gettokens(h->value, kv, nelem(kv), ", ")) == 0)

+		return -1;

+

+	while(n-- > 0){

+		if(gettokens(kv[n], kv2, 2, "=\"") != 2)

+			continue;

+

+		/* XXX: this hack should be replaced by a better method */

+		p = strchr(kv2[1], '"');

+		if(p != nil)

+			*p = 0;

+

+		if(strcmp(kv2[0], "algorithm") == 0)

+			req->auth.algo = strdup(kv2[1]);

+		else if(strcmp(kv2[0], "realm") == 0)

+			req->auth.realm = strdup(kv2[1]);

+		else if(strcmp(kv2[0], "nonce") == 0)

+			req->auth.nonce = strdup(kv2[1]);

+	}

+	if(strcmp(res->auth.algo, "MD5") == 0){

+		snprint(buf, sizeof buf, "sip:%s", s->nci->rsys);

+		res->auth.response = algos[AMD5].fn(user, pass, buf, res);

+		if(res->auth.response == nil)

+			return -1;

+	}else

+		return -1;

+

+	req = newsipmsg();

+	req->method = REGISTER;

+	req->uri = strdup(buf);

+	req->version = sipversion;

+	snprint(buf, sizeof buf, "%s/UDP %s:%s;branch=z9hG4bK703d971c0c737b8e;rport",

+		sipversion, s->nci->lsys, s->nci->lserv);

+	addheader(req, "Via", buf);

+	snprint(buf, sizeof buf, "<sip:%s-0x82a66a010@%s:%s>;expires=3849",

+		user, s->nci->lsys, s->nci->lserv);

+	addheader(req, "Contact", buf);

+	snprint(buf, sizeof buf, "Digest username=\"%s\", realm=\"%s\", nonce=\"%s\", uri=\"%s\", response=\"%s\", algorithm=\"%s\"",

+		user, res->auth.realm, res->auth.nonce, req->uri, res->auth.response, res->auth.algo);

+	addheader(req, "Authorization", buf);

+	addheader(req, "Max-Forwards", "70");

+	snprint(buf, sizeof buf, "<sip:%s@%s>",

+		user, s->nci->rsys);

+	addheader(req, "To", buf);

+	snprint(buf, sizeof buf, "<sip:%s@%s>;tag=4a5a693256d38cbc",

+		user, s->nci->rsys);

+	addheader(req, "From", buf);

+	addheader(req, "Call-ID", "2cee372fc4be4e45");

+	addheader(req, "CSeq", "16022 REGISTER");

+	addheader(req, "User-Agent", useragent);

+	addheader(req, "Allow", "INVITE,ACK,BYE,CANCEL,OPTIONS,NOTIFY,SUBSCRIBE,INFO,MESSAGE,UPDATE,REFER");

+	snprint(buf, sizeof buf, "%lud", req->len);

+	addheader(req, "Content-Length", buf);

+

+	Bprint(bout, "%S", req);

+	Bflush(bout);

+

+	if(debug)

+		fprint(2, "sent:\n%S\n", req);

+

+	delsipmsg(res);

+	delsipmsg(req);

+

+	/* get the OK */

+	res = newsipmsg();

+	while((line = Brdline(bin, '\n')) != nil){

+		if(strncmp(line, "\r\n", 2) == 0)

+			break;

+

+		p = strchr(line, '\r');

+		*p++ = 0, *p = 0;

+

+		if(strstr(line, ":") == nil && req->code == 0){

+			if(gettokens(line, kv, 3, " ") == 3){

+				res->version = strdup(kv[0]);

+				res->code = strtoul(kv[1], nil, 10);

+				res->reason = strdup(kv[2]);

+			}

+			continue;

+		}

+

+		if(gettokens(line, kv, 2, ": ") == 2)

+			addheader(res, kv[0], kv[1]);

+	}

+

+	if(debug)

+		fprint(2, "rcvd:\n%S\n", res);

+

+	Bterm(bin);

+	Bterm(bout);

+

+	return 0;

+}

+

+int

+Sfmt(Fmt *f)

+{

+	Sipmsg *m;

+	Hdr *h;

+	int i, n;

+

+	m = va_arg(f->args, Sipmsg*);

+	n = 0;

+

+	if(m->code == 0){ /* request */

+		n += fmtprint(f, "%s %s %s\r\n",

+			getmethodstr(m->method), m->uri, m->version);

+	}else{ /* response */

+		n += fmtprint(f, "%s %d %s\r\n",

+			m->version, m->code, m->reason);

+	}

+

+	for(i = 0; i < nelem(m->headers); i++)

+		for(h = m->headers[i]; h != nil; h = h->next)

+			n += fmtprint(f, "%s: %s\r\n", h->name, h->value);

+	n += fmtprint(f, "\r\n");

+

+	if(m->len > 0){

+		fmtprint(f, "%.*s", (int)m->len, m->body);

+		n += m->len;

+	}

+

+	return n;

+}

+

 void

+SIPfmtinstall(void)

+{

+	fmtinstall('S', Sfmt);

+}

+

+void

 addheader(Hdrtab *ht, char *name, char *value)

 {

 	Hdr *h, *newh;

@@ -133,53 +385,26 @@

 		}

 }

-/* rfc3261 § 10 - Registrations */

-static int

-sip_register(Sip *s, char *user, char *pass)

+Sipmsg *

+newsipmsg(void)

 {

-	Biobuf *bin, *bout;

-	char *line, *p, *kv[2];

-	int n;

+	Sipmsg *m;

-	if((bin = Bfdopen(s->fd, OREAD)) == nil)

-		sysfatal("Bfdopen: %r");

-	if((bout = Bfdopen(s->fd, OWRITE)) == nil)

-		sysfatal("Bfdopen: %r");

+	m = emalloc(sizeof(Sipmsg));

+	memset(m, 0, sizeof *m);

-	/* present yourself */

-	Bprint(bout, registerhdr0, s->nci->rsys, sipversion,

-		sipversion, s->nci->lsys, s->nci->lserv,

-		user, s->nci->lsys, s->nci->lserv,

-		user, s->nci->rsys,

-		user, s->nci->rsys);

-	Bflush(bout);

+	return m;

+}

-	/* wait for the challenge */

-	while((line = Brdline(bin, '\n')) != nil){

-		if(strncmp(line, "\r\n", 2) == 0)

-			break;

-

-		p = strchr(line, '\r');

-		*p++ = 0, *p = 0;

-		if(debug)

-			fprint(2, "%s\n", line);

-

-		if(strstr(line, ":") == nil)

-			continue;

-

-		gettokens(line, kv, nelem(kv), ": ");

-		if(debug)

-			fprint(2, "got key=%s value=%s\n", kv[0], kv[1]);

-	}

-

-	/* respond to the challenge */

-

-	/* get the OK */

-

-	Bterm(bin);

-	Bterm(bout);

-

-	return 0;

+void

+delsipmsg(Sipmsg *m)

+{

+	if(m->uri != nil)

+		free(m->uri);

+	if(m->reason != nil)

+		free(m->reason);

+	delheaders(m);

+	free(m);

 }

 Sip *