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git/connect.c
Junio C Hamano ec587fde0a Make sure git_connect() always give two file descriptors. 
Earlier, git_connect() returned the same fd twice or two
separate fds, depending on the way the connection was made (when
we are talking to the other end over a single socket, we used
the same fd twice, and when our end is connected to a pipepair
we used two).

This forced callers who do close() and dup() to really care
which was which, and most of the existing callers got this
wrong, although without much visible ill effect.  Many were
closing the same fd twice when we are talking over a single
socket, and one was leaking a fd.

This fixes it to uniformly use two separate fds, so if somebody
wants to close only reader side can just do close() on it
without worrying about it accidentally also closing the writer
side or vice versa.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-01-21 21:51:01 -08:00

806 lines
17 KiB
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#include "git-compat-util.h"
#include "cache.h"
#include "pkt-line.h"
#include "quote.h"
#include "refs.h"
static char *server_capabilities;
static int check_ref(const char *name, int len, unsigned int flags)
{
if (!flags)
return 1;
if (len < 5 || memcmp(name, "refs/", 5))
return 0;
/* Skip the "refs/" part */
name += 5;
len -= 5;
/* REF_NORMAL means that we don't want the magic fake tag refs */
if ((flags & REF_NORMAL) && check_ref_format(name) < 0)
return 0;
/* REF_HEADS means that we want regular branch heads */
if ((flags & REF_HEADS) && !memcmp(name, "heads/", 6))
return 1;
/* REF_TAGS means that we want tags */
if ((flags & REF_TAGS) && !memcmp(name, "tags/", 5))
return 1;
/* All type bits clear means that we are ok with anything */
return !(flags & ~REF_NORMAL);
}
/*
* Read all the refs from the other end
*/
struct ref **get_remote_heads(int in, struct ref **list,
int nr_match, char **match,
unsigned int flags)
{
*list = NULL;
for (;;) {
struct ref *ref;
unsigned char old_sha1[20];
static char buffer[1000];
char *name;
int len, name_len;
len = packet_read_line(in, buffer, sizeof(buffer));
if (!len)
break;
if (buffer[len-1] == '\n')
buffer[--len] = 0;
if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
die("protocol error: expected sha/ref, got '%s'", buffer);
name = buffer + 41;
name_len = strlen(name);
if (len != name_len + 41) {
if (server_capabilities)
free(server_capabilities);
server_capabilities = xstrdup(name + name_len + 1);
}
if (!check_ref(name, name_len, flags))
continue;
if (nr_match && !path_match(name, nr_match, match))
continue;
ref = xcalloc(1, sizeof(*ref) + len - 40);
hashcpy(ref->old_sha1, old_sha1);
memcpy(ref->name, buffer + 41, len - 40);
*list = ref;
list = &ref->next;
}
return list;
}
int server_supports(const char *feature)
{
return server_capabilities &&
strstr(server_capabilities, feature) != NULL;
}
int get_ack(int fd, unsigned char *result_sha1)
{
static char line[1000];
int len = packet_read_line(fd, line, sizeof(line));
if (!len)
die("git-fetch-pack: expected ACK/NAK, got EOF");
if (line[len-1] == '\n')
line[--len] = 0;
if (!strcmp(line, "NAK"))
return 0;
if (!strncmp(line, "ACK ", 4)) {
if (!get_sha1_hex(line+4, result_sha1)) {
if (strstr(line+45, "continue"))
return 2;
return 1;
}
}
die("git-fetch_pack: expected ACK/NAK, got '%s'", line);
}
int path_match(const char *path, int nr, char **match)
{
int i;
int pathlen = strlen(path);
for (i = 0; i < nr; i++) {
char *s = match[i];
int len = strlen(s);
if (!len || len > pathlen)
continue;
if (memcmp(path + pathlen - len, s, len))
continue;
if (pathlen > len && path[pathlen - len - 1] != '/')
continue;
*s = 0;
return (i + 1);
}
return 0;
}
struct refspec {
char *src;
char *dst;
char force;
};
/*
* A:B means fast forward remote B with local A.
* +A:B means overwrite remote B with local A.
* +A is a shorthand for +A:A.
* A is a shorthand for A:A.
* :B means delete remote B.
*/
static struct refspec *parse_ref_spec(int nr_refspec, char **refspec)
{
int i;
struct refspec *rs = xcalloc(sizeof(*rs), (nr_refspec + 1));
for (i = 0; i < nr_refspec; i++) {
char *sp, *dp, *ep;
sp = refspec[i];
if (*sp == '+') {
rs[i].force = 1;
sp++;
}
ep = strchr(sp, ':');
if (ep) {
dp = ep + 1;
*ep = 0;
}
else
dp = sp;
rs[i].src = sp;
rs[i].dst = dp;
}
rs[nr_refspec].src = rs[nr_refspec].dst = NULL;
return rs;
}
static int count_refspec_match(const char *pattern,
struct ref *refs,
struct ref **matched_ref)
{
int patlen = strlen(pattern);
struct ref *matched_weak = NULL;
struct ref *matched = NULL;
int weak_match = 0;
int match = 0;
for (weak_match = match = 0; refs; refs = refs->next) {
char *name = refs->name;
int namelen = strlen(name);
int weak_match;
if (namelen < patlen ||
memcmp(name + namelen - patlen, pattern, patlen))
continue;
if (namelen != patlen && name[namelen - patlen - 1] != '/')
continue;
/* A match is "weak" if it is with refs outside
* heads or tags, and did not specify the pattern
* in full (e.g. "refs/remotes/origin/master") or at
* least from the toplevel (e.g. "remotes/origin/master");
* otherwise "git push $URL master" would result in
* ambiguity between remotes/origin/master and heads/master
* at the remote site.
*/
if (namelen != patlen &&
patlen != namelen - 5 &&
strncmp(name, "refs/heads/", 11) &&
strncmp(name, "refs/tags/", 10)) {
/* We want to catch the case where only weak
* matches are found and there are multiple
* matches, and where more than one strong
* matches are found, as ambiguous. One
* strong match with zero or more weak matches
* are acceptable as a unique match.
*/
matched_weak = refs;
weak_match++;
}
else {
matched = refs;
match++;
}
}
if (!matched) {
*matched_ref = matched_weak;
return weak_match;
}
else {
*matched_ref = matched;
return match;
}
}
static void link_dst_tail(struct ref *ref, struct ref ***tail)
{
**tail = ref;
*tail = &ref->next;
**tail = NULL;
}
static struct ref *try_explicit_object_name(const char *name)
{
unsigned char sha1[20];
struct ref *ref;
int len;
if (!*name) {
ref = xcalloc(1, sizeof(*ref) + 20);
strcpy(ref->name, "(delete)");
hashclr(ref->new_sha1);
return ref;
}
if (get_sha1(name, sha1))
return NULL;
len = strlen(name) + 1;
ref = xcalloc(1, sizeof(*ref) + len);
memcpy(ref->name, name, len);
hashcpy(ref->new_sha1, sha1);
return ref;
}
static int match_explicit_refs(struct ref *src, struct ref *dst,
struct ref ***dst_tail, struct refspec *rs)
{
int i, errs;
for (i = errs = 0; rs[i].src; i++) {
struct ref *matched_src, *matched_dst;
matched_src = matched_dst = NULL;
switch (count_refspec_match(rs[i].src, src, &matched_src)) {
case 1:
break;
case 0:
/* The source could be in the get_sha1() format
* not a reference name. :refs/other is a
* way to delete 'other' ref at the remote end.
*/
matched_src = try_explicit_object_name(rs[i].src);
if (matched_src)
break;
errs = 1;
error("src refspec %s does not match any.",
rs[i].src);
break;
default:
errs = 1;
error("src refspec %s matches more than one.",
rs[i].src);
break;
}
switch (count_refspec_match(rs[i].dst, dst, &matched_dst)) {
case 1:
break;
case 0:
if (!memcmp(rs[i].dst, "refs/", 5)) {
int len = strlen(rs[i].dst) + 1;
matched_dst = xcalloc(1, sizeof(*dst) + len);
memcpy(matched_dst->name, rs[i].dst, len);
link_dst_tail(matched_dst, dst_tail);
}
else if (!strcmp(rs[i].src, rs[i].dst) &&
matched_src) {
/* pushing "master:master" when
* remote does not have master yet.
*/
int len = strlen(matched_src->name) + 1;
matched_dst = xcalloc(1, sizeof(*dst) + len);
memcpy(matched_dst->name, matched_src->name,
len);
link_dst_tail(matched_dst, dst_tail);
}
else {
errs = 1;
error("dst refspec %s does not match any "
"existing ref on the remote and does "
"not start with refs/.", rs[i].dst);
}
break;
default:
errs = 1;
error("dst refspec %s matches more than one.",
rs[i].dst);
break;
}
if (errs)
continue;
if (matched_dst->peer_ref) {
errs = 1;
error("dst ref %s receives from more than one src.",
matched_dst->name);
}
else {
matched_dst->peer_ref = matched_src;
matched_dst->force = rs[i].force;
}
}
return -errs;
}
static struct ref *find_ref_by_name(struct ref *list, const char *name)
{
for ( ; list; list = list->next)
if (!strcmp(list->name, name))
return list;
return NULL;
}
int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
int nr_refspec, char **refspec, int all)
{
struct refspec *rs = parse_ref_spec(nr_refspec, refspec);
if (nr_refspec)
return match_explicit_refs(src, dst, dst_tail, rs);
/* pick the remainder */
for ( ; src; src = src->next) {
struct ref *dst_peer;
if (src->peer_ref)
continue;
dst_peer = find_ref_by_name(dst, src->name);
if ((dst_peer && dst_peer->peer_ref) || (!dst_peer && !all))
continue;
if (!dst_peer) {
/* Create a new one and link it */
int len = strlen(src->name) + 1;
dst_peer = xcalloc(1, sizeof(*dst_peer) + len);
memcpy(dst_peer->name, src->name, len);
hashcpy(dst_peer->new_sha1, src->new_sha1);
link_dst_tail(dst_peer, dst_tail);
}
dst_peer->peer_ref = src;
}
return 0;
}
enum protocol {
PROTO_LOCAL = 1,
PROTO_SSH,
PROTO_GIT,
};
static enum protocol get_protocol(const char *name)
{
if (!strcmp(name, "ssh"))
return PROTO_SSH;
if (!strcmp(name, "git"))
return PROTO_GIT;
if (!strcmp(name, "git+ssh"))
return PROTO_SSH;
if (!strcmp(name, "ssh+git"))
return PROTO_SSH;
die("I don't handle protocol '%s'", name);
}
#define STR_(s) # s
#define STR(s) STR_(s)
#ifndef NO_IPV6
/*
* Returns a connected socket() fd, or else die()s.
*/
static int git_tcp_connect_sock(char *host)
{
int sockfd = -1, saved_errno = 0;
char *colon, *end;
const char *port = STR(DEFAULT_GIT_PORT);
struct addrinfo hints, *ai0, *ai;
int gai;
if (host[0] == '[') {
end = strchr(host + 1, ']');
if (end) {
*end = 0;
end++;
host++;
} else
end = host;
} else
end = host;
colon = strchr(end, ':');
if (colon) {
*colon = 0;
port = colon + 1;
}
memset(&hints, 0, sizeof(hints));
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = IPPROTO_TCP;
gai = getaddrinfo(host, port, &hints, &ai);
if (gai)
die("Unable to look up %s (%s)", host, gai_strerror(gai));
for (ai0 = ai; ai; ai = ai->ai_next) {
sockfd = socket(ai->ai_family,
ai->ai_socktype, ai->ai_protocol);
if (sockfd < 0) {
saved_errno = errno;
continue;
}
if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
saved_errno = errno;
close(sockfd);
sockfd = -1;
continue;
}
break;
}
freeaddrinfo(ai0);
if (sockfd < 0)
die("unable to connect a socket (%s)", strerror(saved_errno));
return sockfd;
}
#else /* NO_IPV6 */
/*
* Returns a connected socket() fd, or else die()s.
*/
static int git_tcp_connect_sock(char *host)
{
int sockfd = -1, saved_errno = 0;
char *colon, *end;
char *port = STR(DEFAULT_GIT_PORT), *ep;
struct hostent *he;
struct sockaddr_in sa;
char **ap;
unsigned int nport;
if (host[0] == '[') {
end = strchr(host + 1, ']');
if (end) {
*end = 0;
end++;
host++;
} else
end = host;
} else
end = host;
colon = strchr(end, ':');
if (colon) {
*colon = 0;
port = colon + 1;
}
he = gethostbyname(host);
if (!he)
die("Unable to look up %s (%s)", host, hstrerror(h_errno));
nport = strtoul(port, &ep, 10);
if ( ep == port || *ep ) {
/* Not numeric */
struct servent *se = getservbyname(port,"tcp");
if ( !se )
die("Unknown port %s\n", port);
nport = se->s_port;
}
for (ap = he->h_addr_list; *ap; ap++) {
sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
if (sockfd < 0) {
saved_errno = errno;
continue;
}
memset(&sa, 0, sizeof sa);
sa.sin_family = he->h_addrtype;
sa.sin_port = htons(nport);
memcpy(&sa.sin_addr, *ap, he->h_length);
if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
saved_errno = errno;
close(sockfd);
sockfd = -1;
continue;
}
break;
}
if (sockfd < 0)
die("unable to connect a socket (%s)", strerror(saved_errno));
return sockfd;
}
#endif /* NO_IPV6 */
static void git_tcp_connect(int fd[2], char *host)
{
int sockfd = git_tcp_connect_sock(host);
fd[0] = sockfd;
fd[1] = dup(sockfd);
}
static char *git_proxy_command;
static const char *rhost_name;
static int rhost_len;
static int git_proxy_command_options(const char *var, const char *value)
{
if (!strcmp(var, "core.gitproxy")) {
const char *for_pos;
int matchlen = -1;
int hostlen;
if (git_proxy_command)
return 0;
/* [core]
* ;# matches www.kernel.org as well
* gitproxy = netcatter-1 for kernel.org
* gitproxy = netcatter-2 for sample.xz
* gitproxy = netcatter-default
*/
for_pos = strstr(value, " for ");
if (!for_pos)
/* matches everybody */
matchlen = strlen(value);
else {
hostlen = strlen(for_pos + 5);
if (rhost_len < hostlen)
matchlen = -1;
else if (!strncmp(for_pos + 5,
rhost_name + rhost_len - hostlen,
hostlen) &&
((rhost_len == hostlen) ||
rhost_name[rhost_len - hostlen -1] == '.'))
matchlen = for_pos - value;
else
matchlen = -1;
}
if (0 <= matchlen) {
/* core.gitproxy = none for kernel.org */
if (matchlen == 4 &&
!memcmp(value, "none", 4))
matchlen = 0;
git_proxy_command = xmalloc(matchlen + 1);
memcpy(git_proxy_command, value, matchlen);
git_proxy_command[matchlen] = 0;
}
return 0;
}
return git_default_config(var, value);
}
static int git_use_proxy(const char *host)
{
rhost_name = host;
rhost_len = strlen(host);
git_proxy_command = getenv("GIT_PROXY_COMMAND");
git_config(git_proxy_command_options);
rhost_name = NULL;
return (git_proxy_command && *git_proxy_command);
}
static void git_proxy_connect(int fd[2], char *host)
{
const char *port = STR(DEFAULT_GIT_PORT);
char *colon, *end;
int pipefd[2][2];
pid_t pid;
if (host[0] == '[') {
end = strchr(host + 1, ']');
if (end) {
*end = 0;
end++;
host++;
} else
end = host;
} else
end = host;
colon = strchr(end, ':');
if (colon) {
*colon = 0;
port = colon + 1;
}
if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
die("unable to create pipe pair for communication");
pid = fork();
if (!pid) {
dup2(pipefd[1][0], 0);
dup2(pipefd[0][1], 1);
close(pipefd[0][0]);
close(pipefd[0][1]);
close(pipefd[1][0]);
close(pipefd[1][1]);
execlp(git_proxy_command, git_proxy_command, host, port, NULL);
die("exec failed");
}
if (pid < 0)
die("fork failed");
fd[0] = pipefd[0][0];
fd[1] = pipefd[1][1];
close(pipefd[0][1]);
close(pipefd[1][0]);
}
#define MAX_CMD_LEN 1024
/*
* This returns 0 if the transport protocol does not need fork(2),
* or a process id if it does. Once done, finish the connection
* with finish_connect() with the value returned from this function
* (it is safe to call finish_connect() with 0 to support the former
* case).
*
* Does not return a negative value on error; it just dies.
*/
pid_t git_connect(int fd[2], char *url, const char *prog)
{
char *host, *path = url;
char *end;
int c;
int pipefd[2][2];
pid_t pid;
enum protocol protocol = PROTO_LOCAL;
int free_path = 0;
/* Without this we cannot rely on waitpid() to tell
* what happened to our children.
*/
signal(SIGCHLD, SIG_DFL);
host = strstr(url, "://");
if(host) {
*host = '\0';
protocol = get_protocol(url);
host += 3;
c = '/';
} else {
host = url;
c = ':';
}
if (host[0] == '[') {
end = strchr(host + 1, ']');
if (end) {
*end = 0;
end++;
host++;
} else
end = host;
} else
end = host;
path = strchr(end, c);
if (c == ':') {
if (path) {
protocol = PROTO_SSH;
*path++ = '\0';
} else
path = host;
}
if (!path || !*path)
die("No path specified. See 'man git-pull' for valid url syntax");
/*
* null-terminate hostname and point path to ~ for URL's like this:
* ssh://host.xz/~user/repo
*/
if (protocol != PROTO_LOCAL && host != url) {
char *ptr = path;
if (path[1] == '~')
path++;
else {
path = xstrdup(ptr);
free_path = 1;
}
*ptr = '\0';
}
if (protocol == PROTO_GIT) {
/* These underlying connection commands die() if they
* cannot connect.
*/
char *target_host = xstrdup(host);
if (git_use_proxy(host))
git_proxy_connect(fd, host);
else
git_tcp_connect(fd, host);
/*
* Separate original protocol components prog and path
* from extended components with a NUL byte.
*/
packet_write(fd[1],
"%s %s%chost=%s%c",
prog, path, 0,
target_host, 0);
free(target_host);
if (free_path)
free(path);
return 0;
}
if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
die("unable to create pipe pair for communication");
pid = fork();
if (pid < 0)
die("unable to fork");
if (!pid) {
char command[MAX_CMD_LEN];
char *posn = command;
int size = MAX_CMD_LEN;
int of = 0;
of |= add_to_string(&posn, &size, prog, 0);
of |= add_to_string(&posn, &size, " ", 0);
of |= add_to_string(&posn, &size, path, 1);
if (of)
die("command line too long");
dup2(pipefd[1][0], 0);
dup2(pipefd[0][1], 1);
close(pipefd[0][0]);
close(pipefd[0][1]);
close(pipefd[1][0]);
close(pipefd[1][1]);
if (protocol == PROTO_SSH) {
const char *ssh, *ssh_basename;
ssh = getenv("GIT_SSH");
if (!ssh) ssh = "ssh";
ssh_basename = strrchr(ssh, '/');
if (!ssh_basename)
ssh_basename = ssh;
else
ssh_basename++;
execlp(ssh, ssh_basename, host, command, NULL);
}
else {
unsetenv(ALTERNATE_DB_ENVIRONMENT);
unsetenv(DB_ENVIRONMENT);
unsetenv(GIT_DIR_ENVIRONMENT);
unsetenv(GRAFT_ENVIRONMENT);
unsetenv(INDEX_ENVIRONMENT);
execlp("sh", "sh", "-c", command, NULL);
}
die("exec failed");
}
fd[0] = pipefd[0][0];
fd[1] = pipefd[1][1];
close(pipefd[0][1]);
close(pipefd[1][0]);
if (free_path)
free(path);
return pid;
}
int finish_connect(pid_t pid)
{
if (pid == 0)
return 0;
while (waitpid(pid, NULL, 0) < 0) {
if (errno != EINTR)
return -1;
}
return 0;
}
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