ref: 53a45f053e40abb04d4d72eff89a3cc79e287b2c
dir: /proto.c/
#include <u.h>
#include <libc.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"
int chattygit;
int
readpkt(Conn *c, char *buf, int nbuf)
{
char len[5];
char *e;
int n;
if(readn(c->rfd, len, 4) == -1)
return -1;
len[4] = 0;
n = strtol(len, &e, 16);
if(n == 0){
if(chattygit)
fprint(2, "readpkt: 0000\n");
return 0;
}
if(e != len + 4 || n <= 4)
sysfatal("invalid packet line length");
n -= 4;
if(n >= nbuf)
sysfatal("buffer too small");
if(readn(c->rfd, buf, n) != n)
return -1;
buf[n] = 0;
if(chattygit)
fprint(2, "readpkt: %s:\t%.*s\n", len, nbuf, buf);
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;
if(chattygit){
fprint(2, "writepkt: %s:\t", len);
write(2, buf, nbuf);
write(2, "\n", 1);
}
return 0;
}
int
flushpkt(Conn *c)
{
if(chattygit)
fprint(2, "writepkt: 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 + 1] = 0;
}
int
parseuri(char *uri, char *proto, char *host, char *port, char *path, char *repo)
{
char *s, *p, *q;
int n, hasport;
p = strstr(uri, "://");
if(!p){
werrstr("missing protocol");
return -1;
}
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
hasport = 0;
s = p + 3;
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);
p = strrchr(p, '/') + 1;
if(!p || 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;
}
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;
if(chattygit)
fprint(2, "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;
}
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;
}
int
issmarthttp(Conn *c, char *direction)
{
char buf[Pktmax+1], svc[128];
int n;
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("dumb http protocol not supported");
return -1;
}
if(readpkt(c, buf, sizeof(buf)) != 0){
werrstr("protocol garble: expected flushpkt");
return -1;
}
return 0;
}
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;
}
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);
if(chattygit)
fprint(2, "exec ssh %s %s %s\n", host, cmd, path);
execl("/bin/ssh", "ssh", host, cmd, path, nil);
}else{
close(pfd[0]);
c->type = ConnSsh;
c->rfd = pfd[1];
c->wfd = dup(pfd[1], -1);
return 0;
}
return -1;
}
int
dialgit(Conn *c, char *host, char *port, char *path, char *direction)
{
char *ds, *p, *e, cmd[512];
int fd;
ds = netmkaddr(host, "tcp", port);
if(chattygit)
fprint(2, "dial %s git-%s-pack %s\n", ds, direction, path);
fd = dial(ds, nil, nil, nil);
if(fd == -1)
return -1;
p = cmd;
e = cmd + sizeof(cmd);
p = seprint(p, e - 1, "git-%s-pack %s", direction, path);
p = seprint(p + 1, e, "host=%s", host);
c->type = ConnRaw;
c->rfd = fd;
c->wfd = dup(fd, -1);
if(writepkt(c, cmd, p - cmd + 1) == -1){
fprint(2, "failed to write message\n");
close(fd);
return -1;
}
return 0;
}
int
writephase(Conn *c)
{
char hdr[128];
int n;
if(chattygit)
fprint(2, "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)
{
if(chattygit)
fprint(2, "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 ConnRaw:
break;
case ConnSsh:
free(wait());
break;
case ConnHttp:
close(c->cfd);
break;
}
}