shithub: rtmp

ref: 489f4a7962adf0243e6a1f81a97b564823970b80
dir: /rtmp.c/

#include <u.h>
#include <libc.h>
#include <thread.h>
#include <bio.h>
#include <libsec.h>
#include "amf0.h"
#include "ivf.h"
#include "rtmp.h"
#include "util.h"

#define min(a,b) ((a)<(b)?(a):(b))

enum {
	Port = 1935,
	CSsz = 1536,
	ChunkDefault = 128,
	ChunkDesired = 65536,

	FlKey = 1<<0,
	FlHdr = 1<<1,

	Type0 = 0,
	Type1,
	Type2,
	Type3,

	CSUserCtl = 2,
	CSCtl = 3,
	CSData = 4,

	CbCommand = 0,
	CbTransID,
	CbObject,
	CbResponse,
	NumCb,

	/* UserControl */
	CtlStreamBegin = 0,
	CtlStreamEOF,
	CtlStreamDry,
	CtlSetBufferLen,
	CtlStreamIsRecorded,
	CtlPingRequest = 6,
	CtlPingResponse,

	/* Message.type */
	SetChunkSize = 1,
	Abort,
	Ack,
	UserControl,
	WindowAckSize,
	SetBandwidth,
	Audio = 8,
	Video,
	AMF3Metadata = 15,
	AMF3SharedObject,
	AMF3Command,
	AMF0Metadata,
	AMF0SharedObject,
	AMF0Command,
	Aggregate = 22,

	/* RTMP.bwlimit */
	LimitHard = 0,
	LimitSoft,
	LimitDynamic,

	Biobufsz = 64*1024, /* FIXME don't know if it helps with anything */
	Bufsz = 64*1024,
};

typedef struct Buffer Buffer;
typedef struct Command Command;
typedef struct Message Message;

#pragma varargck type "T" int
#pragma varargck type "M" Message*

struct Command {
	void (*cb)(RTMP *r, int ok, A₀ *a[NumCb], void *aux);
	char *code;
	void *aux;
	int tid;
	int cs;

	Command *prev, *next;
};

struct Message {
	int type;
	int fmt;
	int cs;
	int sid;
	u32int ts;
	u8int *data;
	int sz;
	Command cmd;
};

struct Buffer {
	Message msg;
	u8int *b, *p, *e;
	int bsz;
};

struct RTMP {
	Biobufhdr;
	QLock;
	Buffer i;
	Buffer o;
	Channel *c;
	char *tcurl;
	char *app;
	char *inst;
	char *path; /* FIXME no idea what this is for */
	int chunkin;
	int chunkout;
	int mode;
	int fd;
	int winacksz;
	int bw;
	u8int bwlimit;
	struct {
		int tid;
		Command *w;
	}cmds;
	int sps;
	u8int biobuf[Biobufsz];
};

#define putnull() do{ r->o.p = a₀null(r->o.p, r->o.e); }while(0)
#define putbyte(b) do{ r->o.p = a₀byte(r->o.p, r->o.e, b); }while(0)
#define putdata(d, sz) do { r->o.p = a₀data(r->o.p, r->o.e, d, sz); }while(0)
#define puti16(i) do{ r->o.p = a₀i16(r->o.p, r->o.e, i); }while(0)
#define puti24(i) do{ r->o.p = a₀i24(r->o.p, r->o.e, i); }while(0)
#define puti32(i) do{ r->o.p = a₀i32(r->o.p, r->o.e, i); }while(0)
#define putnum(v) do{ r->o.p = a₀num(r->o.p, r->o.e, v); }while(0)
#define putstr(s) do{ r->o.p = a₀str(r->o.p, r->o.e, s); }while(0)
#define putarr() do{ r->o.p = a₀arr(r->o.p, r->o.e); }while(0)
#define putobj() do{ r->o.p = a₀obj(r->o.p, r->o.e); }while(0)
#define putend() do{ r->o.p = a₀end(r->o.p, r->o.e); }while(0)
#define putkvnum(name, v) do{ r->o.p = a₀kvnum(r->o.p, r->o.e, name, v); }while(0)
#define putkvstr(name, s) do{ r->o.p = a₀kvstr(r->o.p, r->o.e, name, s); }while(0)
#define putkvbool(name, s) do{ r->o.p = a₀kvbool(r->o.p, r->o.e, name, s); }while(0)

#define putcommand(name, cb_) do { \
	putstr(name); \
	putnum(r->o.msg.cmd.tid); \
	putobj(); \
	r->o.msg.cmd.cb = cb_; \
}while(0)

#define putcall(name) do { \
	putstr(name); \
	putnum(r->o.msg.cmd.tid); \
}while(0)

static int szs[] = {
	[Type3] = 0,
	[Type2] = 3,
	[Type1] = 7,
	[Type0] = 11,
};

static char *msgtype2s[] = {
	[SetChunkSize] = "SetChunkSize",
	[Abort] = "Abort",
	[Ack] = "Ack",
	[UserControl] = "UserControl",
	[WindowAckSize] = "WindowAckSize",
	[SetBandwidth] = "SetBandwidth",
	[Audio] = "Audio",
	[Video] = "Video",
	[AMF3Metadata] = "AMF3Metadata",
	[AMF3SharedObject] = "AMF3SharedObject",
	[AMF3Command] = "AMF3Command",
	[AMF0Metadata] = "AMF0Metadata",
	[AMF0SharedObject] = "AMF0SharedObject",
	[AMF0Command] = "AMF0Command",
	[Aggregate] = "Aggregate",
};

static char *ctl2s[] = {
	[CtlStreamBegin] = "StreamBegin",
	[CtlStreamEOF] = "StreamEOF",
	[CtlStreamDry] = "StreamDry",
	[CtlSetBufferLen] = "SetBufferLen",
	[CtlStreamIsRecorded] = "StreamIsRecorded",
	[CtlPingRequest] = "PingRequest",
	[CtlPingResponse] = "PingResponse",
};

static char *bwlimit2s[] = {
	[LimitHard] = "hard",
	[LimitSoft] = "soft",
	[LimitDynamic] = "dynamic",
};

static char *pubtype2s[] = {
	[PubLive] = "live",
	[PubAppend] = "append",
	[PubRecord] = "record",
};

extern int debug;

static void
newmsg(RTMP *r, int type, int fmt, int cs)
{
	memset(&r->o.msg, 0, sizeof(r->o.msg));

	r->o.msg.type = type;
	r->o.msg.fmt = fmt;
	r->o.msg.cs = cs;
	r->o.p = r->o.b;
	if(type == AMF0Command)
		r->o.msg.cmd.tid = ++r->cmds.tid;
	else
		r->o.msg.cmd.tid = 0;
	r->o.msg.cmd.cs = cs;
}

static void
notransaction(RTMP *r)
{
	r->o.msg.cmd.tid = 0;
}

static void
bextend(Buffer *b, int bsz)
{
	u8int *ob;

	if(b->bsz >= bsz)
		return;
	ob = b->b;
	b->b = erealloc(ob, bsz*2);
	if(ob != nil)
		b->p = b->b + (intptr)(ob - b->p);
	b->bsz = bsz*2;
	b->e = b->b + b->bsz;
}

static int
rtmprecv(RTMP *r)
{
	int hsz, len, n, msid;
	u8int *h, *e, byte;
	u32int ts;

	memset(&r->i.msg, 0, sizeof(r->i.msg));

	r->i.p = r->i.b;
	if((n = readn(r->fd, &byte, 1)) != 1){
		if(n == 0)
			werrstr("eof");
		goto err;
	}

	r->i.msg.fmt = (byte & 0xc0)>>6;
	r->i.msg.cs = byte & 0x3f;
	n = r->i.msg.cs + 1;
	if(n <= 2){
		if(readn(r->fd, r->i.p, n) != n)
			goto err;
		r->i.msg.cs = 64 + r->i.p[0];
		if(n == 2)
			r->i.msg.cs += 256 * r->i.p[1];
	}

	hsz = szs[r->i.msg.fmt];
	if(readn(r->fd, r->i.p, hsz) != hsz)
		goto err;

	h = r->i.p;
	e = r->i.p + hsz;

	r->i.msg.type = -1;
	msid = 0;
	ts = 0;
	len = 0;
	if(hsz >= szs[Type2]){
		h = a₀i24get(h, e, (s32int*)&ts); /* FIXME proper timestamps? */
		if(hsz >= szs[Type1]){
			h = a₀i24get(h, e, &len);
			h = a₀byteget(h, e, &byte);
			r->i.msg.type = byte;
			if(hsz >= szs[Type0])
				h = a₀i32leget(h, e, &msid);
		}
	}

	if(ts == 0xffffff){ /* exntended timestamp */
		if(readn(r->fd, h, 4) != 4)
			goto err;
		h = a₀i32get(h, h+4, (s32int*)&ts);
	}

	/* FIXME do all consecutive chunks use Type3? */
	bextend(&r->i, len);
	r->i.msg.data = h;
	r->i.msg.sz = len;
	for(;;){
		n = min(len, r->chunkin);
		if(readn(r->fd, h, n) != n)
			goto err;
		len -= n;
		h += n;
		if(len < 1)
			break;
		if(readn(r->fd, h, 1) != 1)
			goto err;
		if((r->i.msg.cs | Type3<<6) != *h){
			werrstr("cs/fmt does not match: %02x", *h);
			goto err;
		}
	}

	return 0;
err:
	werrstr("rtmprecv: %r");
	return -1;
}

static int
rtmpsend(RTMP *r)
{
	u8int *p, *h, *e, hdata[24];
	int len, n, hsz;
	Command *c;
	Message *m;

	if(r->o.p == nil)
		goto err;

	m = &r->o.msg;
	m->data = r->o.b;
	m->sz = r->o.p - r->o.b;

	h = hdata;
	*h++ = m->fmt<<6 | m->cs;
	hsz = szs[m->fmt];
	e = h + hsz;
	if(hsz >= szs[Type2]){
		h = a₀i24(h, e, m->ts);
		if(hsz >= szs[Type1]){
			h = a₀i24(h, e, m->sz);
			h = a₀byte(h, e, m->type);
			if(hsz >= szs[Type0])
				h = a₀i32le(h, e, m->sid);
		}
	}
	assert(h != nil);
	memset(h, 0, e-h);
	if(Bwrite(r, hdata, h-hdata) < 0)
		goto err;

	for(p = m->data, len = m->sz; len > 0;){
		n = min(len, r->chunkout);
		if(Bwrite(r, p, n) < 0)
			goto err;
		p += n;
		len -= n;
		if(len > 0){
			*h = m->cs | Type3<<6;
			Bputc(r, *h);
		}
	}

	if(Bflush(r) < 0)
		goto err;

	if(debug){
		fprint(2, "← %M", m);
		if(m->type == AMF0Command){
			A₀ *a;
			u8int *s, *e;
			fprint(2, ":");
			s = m->data;
			e = s + m->sz;
			for(; s != nil && s != e;){
				if((s = a₀parse(&a, s, e)) != nil)
					fprint(2, " %A", a);
				else
					fprint(2, " %r");
				a₀free(a);
			}
		}
		fprint(2, "\n");
	}

	if(m->type == AMF0Command){
		c = emalloc(sizeof(*c));
		*c = m->cmd;
		assert(c->cb != nil);
		if((c->next = r->cmds.w) != nil)
			c->next->prev = c;
		r->cmds.w = c;
	}

	return 0;
err:
	werrstr("rtmpsend: %r");
	return -1;
}

static void
rtmpfree(RTMP *r)
{
	free(r->i.b);
	free(r->o.b);
	free(r->tcurl);
	free(r->app);
	free(r->inst);
	free(r->path);
	if(r->c != nil){
		sendp(r->c, "done");
		chanfree(r->c);
	}
	Bterm(r);
	free(r);
}

static int
pong(RTMP *r, s32int n)
{
	newmsg(r, UserControl, Type0, CSUserCtl);
	puti16(CtlPingResponse);
	puti32(n);

	return rtmpsend(r);
}

static int
setchunksz(RTMP *r, int sz)
{
	int n;

	newmsg(r, SetChunkSize, Type0, CSUserCtl);
	puti32(sz);
	n = rtmpsend(r);
	r->chunkout = sz;

	return n;
}

static void
loop(void *aux)
{
	int res, n, ok, i;
	A₀ *a[NumCb], *v;
	u8int *s, *e;
	s16int s16;
	Message *m;
	Command *c;
	char *k;
	RTMP *r;

	r = aux;
	m = &r->i.msg;
	res = 0;
	memset(a, 0, sizeof(a));
	for(;;){
		for(n = 0; n < nelem(a); n++)
			a₀free(a[n]);
		memset(a, 0, sizeof(a));

		if(res != 0 || (res = rtmprecv(r)) != 0){
			if(debug)
				fprint(2, "rtmp loop: %r\n");
			for(n = 0; n < nelem(a); n++)
				a₀free(a[n]);
			break;
		}

		s = m->data;
		e = s + m->sz;

		qlock(r);

		if(debug)
			fprint(2, "→ %M", m);

		switch(m->type){
		case AMF0Command:
			c = nil;
			ok = 1;
			for(n = 0; n < NumCb; n++){
				if((s = a₀parse(&a[n], s, e)) == nil)
					goto err;
				switch(n){
				case CbCommand:
					if(a[n]->type != Tstr){
						werrstr("command name is not a string: %A", a[n]);
						goto err;
					}
					if(strcmp(a[n]->str, "_error") == 0)
						ok = 0;
					/* other values: "_result", etc */
					break;
				case CbTransID:
					if(a[n]->type != Tnum){
						werrstr("transaction ID is not a number");
						goto err;
					}
					if(a[n]->num == 0) /* no transaction, will try matching with response */
						break;
					for(c = r->cmds.w; c != nil; c = c->next){
						/* transaction id match */
						if(c->tid == a[n]->num)
							break;
					}
					break;
				case CbResponse:
					if(a[CbTransID]->num != 0) /* should have matches with the transaction */
						break;
					if(a[n]->type != Tobj)
						break;
					for(i = 0; i < a[n]->obj.n; i++){
						k = a[n]->obj.k[i];
						v = a[n]->obj.v[i];
						if(strcmp(k, "code") == 0 && v->type == Tstr){
							for(c = r->cmds.w; c != nil; c = c->next){
								if(c->code != nil && strcmp(c->code, v->str) == 0)
									break;
							}
							break;
						}
					}
					break;
				}
			}
			if(debug)
				fprint(2, " tid=%A: %A %A %A\n", a[CbTransID], a[CbCommand], a[CbObject], a[CbResponse]);
			if(c != nil){
				if(c->prev != nil)
					c->prev->next = c->next;
				if(c->next != nil)
					c->next->prev = c->prev;
				if(r->cmds.w == c)
					r->cmds.w = c->next;
				c->cb(r, ok, a, c->aux);
				free(c);
			}else if(a[CbTransID] != nil){
				fprint(2, "response/command with no handler (transaction %d)\n", (int)a[CbTransID]->num);
			}
			break;

		case SetChunkSize:
			if(a₀i32get(s, e, &r->chunkin) == nil)
				goto err;
			if(r->chunkin < 2){
				werrstr("invalid chunk size: %d", r->chunkin);
				goto err;
			}
			if(debug)
				fprint(2, ": %d\n", r->chunkin);
			break;

		case UserControl:
			if((s = a₀i16get(s, e, &s16)) == nil)
				goto err;
			if(a₀i32get(s, e, &n) == nil)
				n = -1;
			switch(s16){
			case CtlStreamBegin:
			case CtlStreamEOF:
			case CtlStreamDry:
			case CtlSetBufferLen:
			case CtlStreamIsRecorded:
				if(0){
			case CtlPingRequest:
					if(pong(r, n) != 0)
						goto err;
				}
				if(debug)
					fprint(2, ": %s %d\n", ctl2s[s16], n);
				break;
			default:
				if(debug)
					fprint(2, ": ?%d? %d\n", s16, n);
				break;
			}
			break;

		case WindowAckSize: /* FIXME send acks too */
			if(a₀i32get(s, e, &r->winacksz) == nil)
				goto err;
			if(debug)
				fprint(2, ": %d\n", r->winacksz);
			break;

		case SetBandwidth:
			if((s = a₀i32get(s, e, &r->bw)) == nil || a₀byteget(s, e, &r->bwlimit) == nil)
				goto err;
			if(debug)
				fprint(2, ": %d (%s)\n", r->bw, r->bwlimit < nelem(bwlimit2s) ? bwlimit2s[r->bwlimit] : "???");
			break;

		/* FIXME */
		case Aggregate:
		case Abort:
		case Ack:
		case Audio:
		case Video:
		case AMF0Metadata:
		case AMF0SharedObject:
			break;

		case AMF3Metadata:
		case AMF3SharedObject:
		case AMF3Command:
			if(debug)
				fprint(2, ": ignored\n");
			break;
err:
			res = -1;
			break;
		}

		qunlock(r);
	}

	rtmpfree(r);

	threadexitsall(res == 0 ? nil : "error");
}

static int
handshake(int f)
{
	u8int c[1+CSsz], s[1+CSsz];

	c[0] = 3; /* rtmp v3 */
	memset(c+1, 0, 4+4); /* timestamp + zero */
	prng(c+1+8, CSsz-4-4);
	if(write(f, c, sizeof(c)) != sizeof(c))
		goto err;
	if(readn(f, s, sizeof(s)) != sizeof(s))
		goto err;
	if(c[0] != s[0]){
		werrstr("expected version %d, got %d", c[0], s[0]);
		goto err;
	}
	if(write(f, s+1, CSsz) != CSsz)
		goto err;
	if(readn(f, s+1, CSsz) != CSsz)
		goto err;
	if(memcmp(c, s, sizeof(c)) != 0){
		werrstr("C1 != S2");
		goto err;
	}

	return 0;

err:
	werrstr("handshake: %r");
	return -1;
}

static void
streamcreated(RTMP *, int ok, A₀ *a[NumCb], void *aux)
{
	Channel *sid;

	sid = aux;
	if(strcmp(a[CbCommand]->str, "_result") != 0)
		fprint(2, "createStream: expected '_result', got %#q\n", a[CbCommand]->str);
	else if(a[CbResponse]->type != Tnum)
		fprint(2, "createStream: expected stream ID, got NaN\n");
	else if(!ok)
		fprint(2, "createStream: %A\n", a[CbResponse]);
	else
		sendul(sid, (ulong)a[CbResponse]->num);

	chanclose(sid);
}

int
rtmpstream(RTMP *r, ulong *sid)
{
	Channel *c;
	int n;

	c = chancreate(sizeof(ulong), 0);

	qlock(r);

	newmsg(r, AMF0Command, Type0, CSCtl);
	putcall("createStream");
	putnull();

	r->o.msg.cmd.cb = streamcreated;
	r->o.msg.cmd.aux = c;
	n = rtmpsend(r);

	qunlock(r);

	n = (n == 0 && recv(c, sid) == 1) ? 0 : -1;
	chanfree(c);

	return n;
}

static void
streampublished(RTMP *, int ok, A₀ *a[NumCb], void *aux)
{
	Channel *err;

	err = aux;
	if(strcmp(a[CbCommand]->str, "onStatus") != 0)
		fprint(2, "streampublished: expected 'onStatus', got %#q\n", a[CbCommand]->str);
	else if(a[CbResponse]->type != Tobj)
		fprint(2, "streampublished: expected object, got something else\n");
	else if(ok)
		sendp(err, nil);

	chanclose(err);
}

int
rtmppublish(RTMP *r, ulong sid, int type, char *name)
{
	Channel *c;
	char *e;
	int n;

	if(type < 0 || type >= nelem(pubtype2s)){
		werrstr("invalid publish type %d", type);
		return -1;
	}
	if(name == nil && (name = r->inst) == nil){
		werrstr("no name to publish to");
		return -1;
	}

	c = chancreate(sizeof(char*), 0);

	qlock(r);

	newmsg(r, AMF0Command, Type0, CSData);
	putcall("publish");
	putnull();
	putstr(name);
	putstr(pubtype2s[type]);

	r->o.msg.cmd.cb = streampublished;
	r->o.msg.cmd.aux = c;
	r->o.msg.cmd.code = "NetStream.Publish.Start";
	r->o.msg.sid = sid;
	n = rtmpsend(r);

	qunlock(r);

	e = nil;
	n = (n == 0 && recv(c, &e) == 1) ? 0 : -1;
	chanfree(c);

	if(e != nil){
		werrstr("%s", e);
		free(c);
	}

	return (n == 0 && e == nil) ? 0 : -1;
}

int
rtmpmeta(RTMP *r, ulong sid, int vcodec, int w, int h, int acodec)
{
	int res;

	assert(vcodec < 0 || vcodec == VcodecH264);
	assert(acodec < 0 || acodec == AcodecAAC);

	qlock(r);

	newmsg(r, AMF0Metadata, Type0, CSData);

	putstr("@setDataFrame");

	putstr("onMetaData");
	putarr();
	puti32(2 + (vcodec < 0 ? 0 : 3) + (acodec < 0 ? 0 : 1));
	putkvnum("duration", 0);
	putkvnum("filesize", 0);
	if(vcodec >= 0){
		putkvnum("videocodecid", vcodec);
		putkvnum("width", w);
		putkvnum("height", h);
	}
	if(acodec >= 0)
		putkvnum("audiocodecid", acodec);
	putend();
	r->o.msg.sid = sid;

	res = rtmpsend(r);

	qunlock(r);

	return res;
}

static int
nalsz(u8int *p, int sz, int *csz)
{
	int n;

	*csz = 0;
	for(n = 0; n < sz-3;){
		if(p[n] == 0 && p[n+1] == 0){
			if(p[n+2] == 1){
				*csz += 3;
				n += 3;
			}else if(p[n+2] == 0 && p[n+3] == 1){
				*csz += 4;
				n += 4;
			}else
				break;
		}else
			break;
	}

	for(; n < sz-3; n++){
		if(p[n] == 0 && p[n+1] == 0){
			if(p[n+2] == 1)
				return n;
			else if(p[n+2] == 0 && p[n+3] == 1)
				return n;
		}
	}

	return sz;
}

static int
h264data(RTMP *r, ulong sid, u32int dt, u8int *p, int sz)
{
	u8int *p₀, sps[128], pps[128], ps[16+sizeof(sps)+sizeof(pps)];
	int sz₀, csz, nsz, ntype, spssz, ppssz, key, total;

	sz₀ = sz;
	p₀ = p;
	spssz = 0;
	ppssz = 0;
	key = 0;
	for(total = 0; sz > 0; total += 4+nsz, p += nsz, sz -= nsz){
		nsz = nalsz(p, sz, &csz);
		p += csz;
		sz -= csz;
		nsz -= csz;

		ntype = *p & 0x1f;
		if(ntype == 7){
			memmove(sps, p, nsz);
			spssz = nsz;
		}
		if(ntype == 8){
			memmove(pps, p, nsz);
			ppssz = nsz;
		}
		if(ntype == 5)
			key = 1;
	}

	if(spssz > 0 && ppssz > 0 && !r->sps){
		newmsg(r, Video, Type0, CSData);
		r->o.msg.ts = dt;
		r->o.msg.sid = sid;

		putbyte(0x10 | VcodecH264);
		putbyte(0);
		puti24(0);

		p = ps;
		*p++ = 1; /* version */
		*p++ = sps[1]; /* profile */
		*p++ = sps[2]; /* compatibility */
		*p++ = sps[3]; /* level */
		*p++ = 0xfc | 3; /* reserved (6 bits), NULA length size - 1 (2 bits) */
		*p++ = 0xe0 | 1; /* reserved (3 bits), num of SPS (5 bits) */
		*p++ = spssz >> 8;
		*p++ = spssz;
		p = (u8int*)memmove(p, sps, spssz) + spssz;
		*p++ = 1;
		*p++ = ppssz >> 8;
		*p++ = ppssz;
		p = (u8int*)memmove(p, pps, ppssz) + ppssz;

		putdata(ps, p-ps);

		if(rtmpsend(r) < 0)
			return -1;

		r->sps = 1;
	}

	bextend(&r->o, 64+total);

	newmsg(r, Video, Type0, CSData);
	r->o.msg.ts = dt;
	r->o.msg.sid = sid;

	putbyte((key ? 0x10 : 0x20) | VcodecH264);
	putbyte(1);
	puti24(0);

	for(p = p₀, sz = sz₀; sz > 0; p += nsz, sz -= nsz){
		nsz = nalsz(p, sz, &csz);
		p += csz;
		sz -= csz;
		nsz -= csz;

		puti32(nsz);
		putdata(p, nsz);
	}

	return rtmpsend(r);
}

int
rtmpdata(RTMP *r, ulong sid, u32int dt, int type, void *p, int sz)
{
	int res;

	assert(type == Taudio || type == Tvideo);

	qlock(r);
	res = 0;
	if(type == Tvideo)
		res = h264data(r, sid, dt, p, sz);
	qunlock(r);

	return res;
}

static void
connected(RTMP *r, int ok, A₀ *a[NumCb], void *)
{
	char *s;

	s = nil;
	if(ok){
		if(strcmp(a[CbCommand]->str, "_result") != 0)
			s = smprint("expected '_result', got %#q", a[CbCommand]->str);
		else
			setchunksz(r, ChunkDesired);
	}else{
		s = smprint("%A", a[CbResponse]);
	}

	sendp(r->c, s);
}

static int
connect(RTMP *r)
{
	newmsg(r, AMF0Command, Type0, CSCtl);
	putcommand("connect", connected);
		putkvstr("app", r->app);
		putkvstr("tcUrl", r->tcurl);
		putkvstr("type", "nonprivate");
		putkvbool("fpad", 0); /* no proxy */
		putkvnum("audioCodecs", 0x4 | 0x400); /* mp3 + aac */
		putkvnum("videoCodecs", 0x80); /* h.264 */
		putkvnum("videoFunction", 0); /* no frame-accurate seek */
		putkvnum("objectEncoding", 0); /* AMF0 */
	putend();

	return rtmpsend(r);
}

static int
msgtypefmt(Fmt *f)
{
	char *s;
	int t;

	if((t = va_arg(f->args, int)) >= 0 &&
	   t < nelem(msgtype2s) &&
	   (s = msgtype2s[t]) != nil)
		return fmtprint(f, "%s", s);

	return fmtprint(f, "%d", t);
}

static int
msgfmt(Fmt *f)
{
	Message *m;

	m = va_arg(f->args, Message*);
	fmtprint(f, "type=%T cs=%d ts=%ud sz=%d", m->type, m->cs, m->ts, m->sz);

	return 0;
}

RTMP *
rtmpdial(char *url)
{
	char *s, *e, *p, *app, *inst, *path;
	int f, port, ctl;
	RTMP *r;

	fmtinstall('A', a₀fmt);
	fmtinstall('T', msgtypefmt);
	fmtinstall('M', msgfmt);
	quotefmtinstall();

	r = nil;
	f = -1;
	url = estrdup(url); /* since we're changing it in-place */
	if(memcmp(url, "rtmp://", 7) != 0){
		werrstr("invalid url");
		goto err;
	}
	s = url + 7;
	if((e = strpbrk(s, ":/")) == nil){
		werrstr("no path");
		goto err;
	}
	port = 1935;
	if(*e == ':'){
		if((port = strtol(e+1, &p, 10)) < 1 || p == e+1 || *p != '/'){
			werrstr("invalid port");
			goto err;
		}
	}else{
		p = e;
	}
	while(*(++p) == '/');

	s = smprint("tcp!%.*s!%d", (int)(e-s), s, port);
	f = dial(s, nil, nil, &ctl);
	free(s);
	if(f < 0)
		goto err;

	/* rtmp://host:port/app[/inst[/path]] */
	app = p;
	inst = nil;
	path = nil;
	if((s = strchr(p, '/')) != nil){ /* app instance */
		*s = 0;
		inst = s+1;
		if((s = strchr(s+1, '/')) != nil){ /* path */
			*s = 0;
			path = s+1;
		}
	}

	if(handshake(f) != 0)
		goto err;

	r = ecalloc(1, sizeof(*r));
	r->fd = f;
	r->chunkin = ChunkDefault;
	r->chunkout = ChunkDefault;
	r->tcurl = url;
	url = nil;
	r->c = chancreate(sizeof(void*), 0);
	r->app = estrdup(app);
	r->inst = inst == nil ? nil : estrdup(inst);
	r->path = path == nil ? nil : estrdup(path);
	bextend(&r->i, Bufsz);
	bextend(&r->o, Bufsz);
	Binits(r, f, OWRITE, r->biobuf, sizeof(r->biobuf));

	if(connect(r) != 0)
		goto err;
	if(proccreate(loop, r, mainstacksize) < 0)
		goto err;

	/* wait for the connect call to finish */
	if((s = recvp(r->c)) != nil){
		rtmpclose(r);
		werrstr("rtmpdial: %s", s);
		free(s);
		r = nil;
	}

	return r;

err:
	werrstr("rtmpdial: %r");
	if(r != nil)
		rtmpfree(r);
	if(f >= 0)
		close(f);
	free(url);
	return nil;
}

void
rtmpclose(RTMP *r)
{
	if(r == nil)
		return;
	if(r->fd >= 0)
		close(r->fd);
	if(r->c != nil)
		chanclose(r->c);
}