ref: 733c5d6645b133b60d304c38fcb1398f94d0618c
dir: /sys/src/cmd/git/proto.c/
#include <u.h>
#include <libc.h>
#include <ctype.h>
#include "git.h"
#define Useragent "useragent git/2.24.1"
#define Contenthdr "headers Content-Type: application/x-git-%s-pack-request"
#define Accepthdr "headers Accept: application/x-git-%s-pack-result"
enum {
Nproto = 16,
Nport = 16,
Nhost = 256,
Npath = 128,
Nrepo = 64,
Nbranch = 32,
};
void
tracepkt(int v, char *pfx, char *b, int n)
{
char *f;
int o, i;
if(chattygit < v)
return;
o = 0;
f = emalloc(n*4 + 1);
for(i = 0; i < n; i++){
if(isprint(b[i])){
f[o++] = b[i];
continue;
}
f[o++] = '\\';
switch(b[i]){
case '\\': f[o++] = '\\'; break;
case '\n': f[o++] = 'n'; break;
case '\r': f[o++] = 'r'; break;
case '\v': f[o++] = 'v'; break;
case '\0': f[o++] = '0'; break;
default:
f[o++] = 'x';
f[o++] = "0123456789abcdef"[(b[i]>>4)&0xf];
f[o++] = "0123456789abcdef"[(b[i]>>0)&0xf];
break;
}
}
f[o] = '\0';
fprint(2, "%s %04x:\t%s\n", pfx, n, f);
free(f);
}
int
readpkt(Conn *c, char *buf, int nbuf)
{
char len[5];
char *e;
int n;
if(readn(c->rfd, len, 4) != 4){
werrstr("pktline: short read from transport");
return -1;
}
len[4] = 0;
n = strtol(len, &e, 16);
if(n == 0){
dprint(1, "=r=> 0000\n");
return 0;
}
if(e != len + 4 || n <= 4)
sysfatal("pktline: bad length '%s'", len);
n -= 4;
if(n >= nbuf)
sysfatal("pktline: undersize buffer");
if(readn(c->rfd, buf, n) != n)
return -1;
if(n > 4 && strncmp(buf, "ERR ", 4) == 0){
if((e = strrchr(buf, '\n')) != nil)
*e = '\0';
werrstr("%s", buf + 4);
return -1;
}
buf[n] = 0;
tracepkt(1, "=r=>", buf, n);
return n;
}
int
writepkt(Conn *c, char *buf, int nbuf)
{
char len[5];
snprint(len, sizeof(len), "%04x", nbuf + 4);
if(write(c->wfd, len, 4) != 4)
return -1;
if(write(c->wfd, buf, nbuf) != nbuf)
return -1;
tracepkt(1, "<=w=", buf, nbuf);
return 0;
}
int
fmtpkt(Conn *c, char *fmt, ...)
{
char pkt[Pktmax];
va_list ap;
int n;
va_start(ap, fmt);
n = vsnprint(pkt, sizeof(pkt), fmt, ap);
n = writepkt(c, pkt, n);
va_end(ap);
return n;
}
int
flushpkt(Conn *c)
{
dprint(1, "<=w= 0000\n");
return write(c->wfd, "0000", 4);
}
static void
grab(char *dst, int n, char *p, char *e)
{
int l;
l = e - p;
if(l >= n)
sysfatal("overlong component");
memcpy(dst, p, l);
dst[l] = 0;
}
static int
parseuri(char *uri, char *proto, char *host, char *port, char *path, char *repo)
{
char *s, *p, *q;
int n, hasport;
print("uri: \"%s\"\n", uri);
p = strstr(uri, "://");
if(p == nil)
snprint(proto, Nproto, "ssh");
else if(strncmp(uri, "git+", 4) == 0)
grab(proto, Nproto, uri + 4, p);
else
grab(proto, Nproto, uri, p);
*port = 0;
hasport = 1;
if(strcmp(proto, "git") == 0)
snprint(port, Nport, "9418");
else if(strncmp(proto, "https", 5) == 0)
snprint(port, Nport, "443");
else if(strncmp(proto, "http", 4) == 0)
snprint(port, Nport, "80");
else if(strncmp(proto, "hjgit", 5) == 0)
snprint(port, Nport, "17021");
else if(strncmp(proto, "gits", 5) == 0)
snprint(port, Nport, "9419");
else
hasport = 0;
s = (p != nil) ? p + 3 : uri;
p = nil;
if(!hasport){
p = strstr(s, ":");
if(p != nil)
p++;
}
if(p == nil)
p = strstr(s, "/");
if(p == nil || strlen(p) == 1){
werrstr("missing path");
return -1;
}
q = memchr(s, ':', p - s);
if(q){
grab(host, Nhost, s, q);
grab(port, Nport, q + 1, p);
}else{
grab(host, Nhost, s, p);
}
snprint(path, Npath, "%s", p);
if((q = strrchr(p, '/')) != nil)
p = q + 1;
if(strlen(p) == 0){
werrstr("missing repository in uri");
return -1;
}
n = strlen(p);
if(hassuffix(p, ".git"))
n -= 4;
grab(repo, Nrepo, p, p + n);
return 0;
}
static int
webclone(Conn *c, char *url)
{
char buf[16];
int n, conn;
if((c->cfd = open("/mnt/web/clone", ORDWR)) < 0)
goto err;
if((n = read(c->cfd, buf, sizeof(buf)-1)) == -1)
goto err;
buf[n] = 0;
conn = atoi(buf);
/* github will behave differently based on useragent */
if(write(c->cfd, Useragent, sizeof(Useragent)) == -1)
return -1;
dprint(1, "open url %s\n", url);
if(fprint(c->cfd, "url %s", url) == -1)
goto err;
free(c->dir);
c->dir = smprint("/mnt/web/%d", conn);
return 0;
err:
if(c->cfd != -1)
close(c->cfd);
return -1;
}
static int
webopen(Conn *c, char *file, int mode)
{
char path[128];
int fd;
snprint(path, sizeof(path), "%s/%s", c->dir, file);
if((fd = open(path, mode)) == -1)
return -1;
return fd;
}
static int
issmarthttp(Conn *c, char *direction)
{
char buf[Pktmax+1], svc[128];
int fd, n;
if((fd = webopen(c, "contenttype", OREAD)) == -1)
return -1;
n = readn(fd, buf, sizeof(buf) - 1);
close(fd);
if(n == -1)
return -1;
buf[n] = '\0';
snprint(svc, sizeof(svc), "application/x-git-%s-pack-advertisement", direction);
if(strcmp(svc, buf) != 0){
werrstr("dumb http protocol not supported");
return -1;
}
if((n = readpkt(c, buf, sizeof(buf))) == -1)
sysfatal("http read: %r");
buf[n] = 0;
snprint(svc, sizeof(svc), "# service=git-%s-pack\n", direction);
if(strncmp(svc, buf, n) != 0){
werrstr("invalid initial packet line");
return -1;
}
if(readpkt(c, buf, sizeof(buf)) != 0){
werrstr("protocol garble: expected flushpkt");
return -1;
}
return 0;
}
static int
dialhttp(Conn *c, char *host, char *port, char *path, char *direction)
{
char *geturl, *suff, *hsep, *psep;
suff = "";
hsep = "";
psep = "";
if(port && strlen(port) != 0)
hsep = ":";
if(path && path[0] != '/')
psep = "/";
memset(c, 0, sizeof(*c));
geturl = smprint("https://%s%s%s%s%s%s/info/refs?service=git-%s-pack", host, hsep, port, psep, path, suff, direction);
c->type = ConnHttp;
c->url = smprint("https://%s%s%s%s%s%s/git-%s-pack", host, hsep, port, psep, path, suff, direction);
c->cfd = webclone(c, geturl);
free(geturl);
if(c->cfd == -1)
return -1;
c->rfd = webopen(c, "body", OREAD);
c->wfd = -1;
if(c->rfd == -1)
return -1;
if(issmarthttp(c, direction) == -1)
return -1;
c->direction = estrdup(direction);
return 0;
}
static int
dialssh(Conn *c, char *host, char *, char *path, char *direction)
{
int pid, pfd[2];
char cmd[64];
if(pipe(pfd) == -1)
sysfatal("unable to open pipe: %r");
pid = fork();
if(pid == -1)
sysfatal("unable to fork");
if(pid == 0){
close(pfd[1]);
dup(pfd[0], 0);
dup(pfd[0], 1);
snprint(cmd, sizeof(cmd), "git-%s-pack", direction);
dprint(1, "exec ssh '%s' '%s' %s\n", host, cmd, path);
execl("/bin/ssh", "ssh", host, cmd, path, nil);
sysfatal("exec: %r");
}
close(pfd[0]);
c->type = ConnSsh;
c->rfd = pfd[1];
c->wfd = dup(pfd[1], -1);
return 0;
}
static int
githandshake(Conn *c, char *host, char *path, char *direction)
{
char *p, *e, cmd[512];
p = cmd;
e = cmd + sizeof(cmd);
p = seprint(p, e - 1, "git-%s-pack %s", direction, path);
if(host != nil)
p = seprint(p + 1, e, "host=%s", host);
if(writepkt(c, cmd, p - cmd + 1) == -1){
fprint(2, "failed to write message\n");
closeconn(c);
return -1;
}
return 0;
}
static int
dialhjgit(Conn *c, char *host, char *port, char *path, char *direction, int auth)
{
char *ds;
int pid, pfd[2];
if((ds = netmkaddr(host, "tcp", port)) == nil)
return -1;
if(pipe(pfd) == -1)
sysfatal("unable to open pipe: %r");
pid = fork();
if(pid == -1)
sysfatal("unable to fork");
if(pid == 0){
close(pfd[1]);
dup(pfd[0], 0);
dup(pfd[0], 1);
dprint(1, "exec tlsclient -a %s\n", ds);
if(auth)
execl("/bin/tlsclient", "tlsclient", "-a", ds, nil);
else
execl("/bin/tlsclient", "tlsclient", ds, nil);
sysfatal("exec: %r");
}
close(pfd[0]);
c->type = ConnGit9;
c->rfd = pfd[1];
c->wfd = dup(pfd[1], -1);
return githandshake(c, host, path, direction);
}
void
initconn(Conn *c, int rd, int wr)
{
c->type = ConnGit;
c->rfd = rd;
c->wfd = wr;
}
static int
dialgit(Conn *c, char *host, char *port, char *path, char *direction)
{
char *ds;
int fd;
if((ds = netmkaddr(host, "tcp", port)) == nil)
return -1;
dprint(1, "dial %s git-%s-pack %s\n", ds, direction, path);
fd = dial(ds, nil, nil, nil);
if(fd == -1)
return -1;
c->type = ConnGit;
c->rfd = fd;
c->wfd = dup(fd, -1);
return githandshake(c, host, path, direction);
}
static int
servelocal(Conn *c, char *path, char *direction)
{
int pid, pfd[2];
if(pipe(pfd) == -1)
sysfatal("unable to open pipe: %r");
pid = fork();
if(pid == -1)
sysfatal("unable to fork");
if(pid == 0){
close(pfd[1]);
dup(pfd[0], 0);
dup(pfd[0], 1);
execl("/bin/git/serve", "serve", "-w", nil);
sysfatal("exec: %r");
}
close(pfd[0]);
c->type = ConnGit;
c->rfd = pfd[1];
c->wfd = dup(pfd[1], -1);
return githandshake(c, nil, path, direction);
}
static int
localrepo(char *uri, char *path, int npath)
{
int fd;
snprint(path, npath, "%s/.git/../", uri);
fd = open(path, OREAD);
if(fd < 0)
return -1;
if(fd2path(fd, path, npath) != 0){
close(fd);
return -1;
}
close(fd);
return 0;
}
int
gitconnect(Conn *c, char *uri, char *direction)
{
char proto[Nproto], host[Nhost], port[Nport];
char repo[Nrepo], path[Npath];
memset(c, 0, sizeof(Conn));
c->rfd = c->wfd = c->cfd = -1;
if(localrepo(uri, path, sizeof(path)) == 0)
return servelocal(c, path, direction);
if(parseuri(uri, proto, host, port, path, repo) == -1){
werrstr("bad uri %s", uri);
return -1;
}
if(strcmp(proto, "ssh") == 0)
return dialssh(c, host, port, path, direction);
else if(strcmp(proto, "git") == 0)
return dialgit(c, host, port, path, direction);
else if(strcmp(proto, "hjgit") == 0)
return dialhjgit(c, host, port, path, direction, 1);
else if(strcmp(proto, "gits") == 0)
return dialhjgit(c, host, port, path, direction, 0);
else if(strcmp(proto, "http") == 0 || strcmp(proto, "https") == 0)
return dialhttp(c, host, port, path, direction);
werrstr("unknown protocol %s", proto);
return -1;
}
int
writephase(Conn *c)
{
char hdr[128];
int n;
dprint(1, "start write phase\n");
if(c->type != ConnHttp)
return 0;
if(c->wfd != -1)
close(c->wfd);
if(c->cfd != -1)
close(c->cfd);
if((c->cfd = webclone(c, c->url)) == -1)
return -1;
n = snprint(hdr, sizeof(hdr), Contenthdr, c->direction);
if(write(c->cfd, hdr, n) == -1)
return -1;
n = snprint(hdr, sizeof(hdr), Accepthdr, c->direction);
if(write(c->cfd, hdr, n) == -1)
return -1;
if((c->wfd = webopen(c, "postbody", OWRITE)) == -1)
return -1;
c->rfd = -1;
return 0;
}
int
readphase(Conn *c)
{
dprint(1, "start read phase\n");
if(c->type != ConnHttp)
return 0;
if(close(c->wfd) == -1)
return -1;
if((c->rfd = webopen(c, "body", OREAD)) == -1)
return -1;
c->wfd = -1;
return 0;
}
void
closeconn(Conn *c)
{
close(c->rfd);
close(c->wfd);
switch(c->type){
case ConnGit:
break;
case ConnGit9:
case ConnSsh:
free(wait());
break;
case ConnHttp:
close(c->cfd);
break;
}
}