git/connect.c
Junio C Hamano 9907d1359c Merge branch 'jc/upload-pack-send-symref'
One long-standing flaw in the pack transfer protocol used by "git
clone" was that there was no way to tell the other end which branch
"HEAD" points at, and the receiving end needed to guess.  A new
capability has been defined in the pack protocol to convey this
information so that cloning from a repository with more than one
branches pointing at the same commit where the HEAD is at now
reliably sets the initial branch in the resulting repository.

* jc/upload-pack-send-symref:
  t5570: Update for clone-progress-to-stderr branch
  t5570: Update for symref capability
  clone: test the new HEAD detection logic
  connect: annotate refs with their symref information in get_remote_head()
  connect.c: make parse_feature_value() static
  upload-pack: send non-HEAD symbolic refs
  upload-pack: send symbolic ref information as capability
  upload-pack.c: do not pass confusing cb_data to mark_our_ref()
  t5505: fix "set-head --auto with ambiguous HEAD" test
2013-10-30 12:10:06 -07:00

739 lines
16 KiB
C

#include "git-compat-util.h"
#include "cache.h"
#include "pkt-line.h"
#include "quote.h"
#include "refs.h"
#include "run-command.h"
#include "remote.h"
#include "connect.h"
#include "url.h"
#include "string-list.h"
static char *server_capabilities;
static const char *parse_feature_value(const char *, const char *, int *);
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_refname_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);
}
int check_ref_type(const struct ref *ref, int flags)
{
return check_ref(ref->name, strlen(ref->name), flags);
}
static void add_extra_have(struct extra_have_objects *extra, unsigned char *sha1)
{
ALLOC_GROW(extra->array, extra->nr + 1, extra->alloc);
hashcpy(&(extra->array[extra->nr][0]), sha1);
extra->nr++;
}
static void die_initial_contact(int got_at_least_one_head)
{
if (got_at_least_one_head)
die("The remote end hung up upon initial contact");
else
die("Could not read from remote repository.\n\n"
"Please make sure you have the correct access rights\n"
"and the repository exists.");
}
static void parse_one_symref_info(struct string_list *symref, const char *val, int len)
{
char *sym, *target;
struct string_list_item *item;
if (!len)
return; /* just "symref" */
/* e.g. "symref=HEAD:refs/heads/master" */
sym = xmalloc(len + 1);
memcpy(sym, val, len);
sym[len] = '\0';
target = strchr(sym, ':');
if (!target)
/* just "symref=something" */
goto reject;
*(target++) = '\0';
if (check_refname_format(sym, REFNAME_ALLOW_ONELEVEL) ||
check_refname_format(target, REFNAME_ALLOW_ONELEVEL))
/* "symref=bogus:pair */
goto reject;
item = string_list_append(symref, sym);
item->util = target;
return;
reject:
free(sym);
return;
}
static void annotate_refs_with_symref_info(struct ref *ref)
{
struct string_list symref = STRING_LIST_INIT_DUP;
const char *feature_list = server_capabilities;
while (feature_list) {
int len;
const char *val;
val = parse_feature_value(feature_list, "symref", &len);
if (!val)
break;
parse_one_symref_info(&symref, val, len);
feature_list = val + 1;
}
sort_string_list(&symref);
for (; ref; ref = ref->next) {
struct string_list_item *item;
item = string_list_lookup(&symref, ref->name);
if (!item)
continue;
ref->symref = xstrdup((char *)item->util);
}
string_list_clear(&symref, 0);
}
/*
* Read all the refs from the other end
*/
struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
struct ref **list, unsigned int flags,
struct extra_have_objects *extra_have)
{
struct ref **orig_list = list;
int got_at_least_one_head = 0;
*list = NULL;
for (;;) {
struct ref *ref;
unsigned char old_sha1[20];
char *name;
int len, name_len;
char *buffer = packet_buffer;
len = packet_read(in, &src_buf, &src_len,
packet_buffer, sizeof(packet_buffer),
PACKET_READ_GENTLE_ON_EOF |
PACKET_READ_CHOMP_NEWLINE);
if (len < 0)
die_initial_contact(got_at_least_one_head);
if (!len)
break;
if (len > 4 && !prefixcmp(buffer, "ERR "))
die("remote error: %s", buffer + 4);
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) {
free(server_capabilities);
server_capabilities = xstrdup(name + name_len + 1);
}
if (extra_have &&
name_len == 5 && !memcmp(".have", name, 5)) {
add_extra_have(extra_have, old_sha1);
continue;
}
if (!check_ref(name, name_len, flags))
continue;
ref = alloc_ref(buffer + 41);
hashcpy(ref->old_sha1, old_sha1);
*list = ref;
list = &ref->next;
got_at_least_one_head = 1;
}
annotate_refs_with_symref_info(*orig_list);
return list;
}
static const char *parse_feature_value(const char *feature_list, const char *feature, int *lenp)
{
int len;
if (!feature_list)
return NULL;
len = strlen(feature);
while (*feature_list) {
const char *found = strstr(feature_list, feature);
if (!found)
return NULL;
if (feature_list == found || isspace(found[-1])) {
const char *value = found + len;
/* feature with no value (e.g., "thin-pack") */
if (!*value || isspace(*value)) {
if (lenp)
*lenp = 0;
return value;
}
/* feature with a value (e.g., "agent=git/1.2.3") */
else if (*value == '=') {
value++;
if (lenp)
*lenp = strcspn(value, " \t\n");
return value;
}
/*
* otherwise we matched a substring of another feature;
* keep looking
*/
}
feature_list = found + 1;
}
return NULL;
}
int parse_feature_request(const char *feature_list, const char *feature)
{
return !!parse_feature_value(feature_list, feature, NULL);
}
const char *server_feature_value(const char *feature, int *len)
{
return parse_feature_value(server_capabilities, feature, len);
}
int server_supports(const char *feature)
{
return !!server_feature_value(feature, NULL);
}
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;
if (!strcmp(name, "file"))
return PROTO_LOCAL;
die("I don't handle protocol '%s'", name);
}
#define STR_(s) # s
#define STR(s) STR_(s)
static void get_host_and_port(char **host, const char **port)
{
char *colon, *end;
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;
}
}
static void enable_keepalive(int sockfd)
{
int ka = 1;
if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
fprintf(stderr, "unable to set SO_KEEPALIVE on socket: %s\n",
strerror(errno));
}
#ifndef NO_IPV6
static const char *ai_name(const struct addrinfo *ai)
{
static char addr[NI_MAXHOST];
if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
NI_NUMERICHOST) != 0)
strcpy(addr, "(unknown)");
return addr;
}
/*
* Returns a connected socket() fd, or else die()s.
*/
static int git_tcp_connect_sock(char *host, int flags)
{
struct strbuf error_message = STRBUF_INIT;
int sockfd = -1;
const char *port = STR(DEFAULT_GIT_PORT);
struct addrinfo hints, *ai0, *ai;
int gai;
int cnt = 0;
get_host_and_port(&host, &port);
if (!*port)
port = "<none>";
memset(&hints, 0, sizeof(hints));
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = IPPROTO_TCP;
if (flags & CONNECT_VERBOSE)
fprintf(stderr, "Looking up %s ... ", host);
gai = getaddrinfo(host, port, &hints, &ai);
if (gai)
die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
if (flags & CONNECT_VERBOSE)
fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
sockfd = socket(ai->ai_family,
ai->ai_socktype, ai->ai_protocol);
if ((sockfd < 0) ||
(connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
host, cnt, ai_name(ai), strerror(errno));
if (0 <= sockfd)
close(sockfd);
sockfd = -1;
continue;
}
if (flags & CONNECT_VERBOSE)
fprintf(stderr, "%s ", ai_name(ai));
break;
}
freeaddrinfo(ai0);
if (sockfd < 0)
die("unable to connect to %s:\n%s", host, error_message.buf);
enable_keepalive(sockfd);
if (flags & CONNECT_VERBOSE)
fprintf(stderr, "done.\n");
strbuf_release(&error_message);
return sockfd;
}
#else /* NO_IPV6 */
/*
* Returns a connected socket() fd, or else die()s.
*/
static int git_tcp_connect_sock(char *host, int flags)
{
struct strbuf error_message = STRBUF_INIT;
int sockfd = -1;
const char *port = STR(DEFAULT_GIT_PORT);
char *ep;
struct hostent *he;
struct sockaddr_in sa;
char **ap;
unsigned int nport;
int cnt;
get_host_and_port(&host, &port);
if (flags & CONNECT_VERBOSE)
fprintf(stderr, "Looking up %s ... ", host);
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", port);
nport = se->s_port;
}
if (flags & CONNECT_VERBOSE)
fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
memset(&sa, 0, sizeof sa);
sa.sin_family = he->h_addrtype;
sa.sin_port = htons(nport);
memcpy(&sa.sin_addr, *ap, he->h_length);
sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
if ((sockfd < 0) ||
connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
host,
cnt,
inet_ntoa(*(struct in_addr *)&sa.sin_addr),
strerror(errno));
if (0 <= sockfd)
close(sockfd);
sockfd = -1;
continue;
}
if (flags & CONNECT_VERBOSE)
fprintf(stderr, "%s ",
inet_ntoa(*(struct in_addr *)&sa.sin_addr));
break;
}
if (sockfd < 0)
die("unable to connect to %s:\n%s", host, error_message.buf);
enable_keepalive(sockfd);
if (flags & CONNECT_VERBOSE)
fprintf(stderr, "done.\n");
return sockfd;
}
#endif /* NO_IPV6 */
static void git_tcp_connect(int fd[2], char *host, int flags)
{
int sockfd = git_tcp_connect_sock(host, flags);
fd[0] = sockfd;
fd[1] = dup(sockfd);
}
static char *git_proxy_command;
static int git_proxy_command_options(const char *var, const char *value,
void *cb)
{
if (!strcmp(var, "core.gitproxy")) {
const char *for_pos;
int matchlen = -1;
int hostlen;
const char *rhost_name = cb;
int rhost_len = strlen(rhost_name);
if (git_proxy_command)
return 0;
if (!value)
return config_error_nonbool(var);
/* [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 = xmemdupz(value, matchlen);
}
return 0;
}
return git_default_config(var, value, cb);
}
static int git_use_proxy(const char *host)
{
git_proxy_command = getenv("GIT_PROXY_COMMAND");
git_config(git_proxy_command_options, (void*)host);
return (git_proxy_command && *git_proxy_command);
}
static struct child_process *git_proxy_connect(int fd[2], char *host)
{
const char *port = STR(DEFAULT_GIT_PORT);
const char **argv;
struct child_process *proxy;
get_host_and_port(&host, &port);
argv = xmalloc(sizeof(*argv) * 4);
argv[0] = git_proxy_command;
argv[1] = host;
argv[2] = port;
argv[3] = NULL;
proxy = xcalloc(1, sizeof(*proxy));
proxy->argv = argv;
proxy->in = -1;
proxy->out = -1;
if (start_command(proxy))
die("cannot start proxy %s", argv[0]);
fd[0] = proxy->out; /* read from proxy stdout */
fd[1] = proxy->in; /* write to proxy stdin */
return proxy;
}
#define MAX_CMD_LEN 1024
static char *get_port(char *host)
{
char *end;
char *p = strchr(host, ':');
if (p) {
long port = strtol(p + 1, &end, 10);
if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
*p = '\0';
return p+1;
}
}
return NULL;
}
static struct child_process no_fork;
/*
* This returns a dummy child_process if the transport protocol does not
* need fork(2), or a struct child_process object 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 NULL to support
* the former case).
*
* If it returns, the connect is successful; it just dies on errors (this
* will hopefully be changed in a libification effort, to return NULL when
* the connection failed).
*/
struct child_process *git_connect(int fd[2], const char *url_orig,
const char *prog, int flags)
{
char *url;
char *host, *path;
char *end;
int c;
struct child_process *conn = &no_fork;
enum protocol protocol = PROTO_LOCAL;
int free_path = 0;
char *port = NULL;
const char **arg;
struct strbuf cmd;
/* Without this we cannot rely on waitpid() to tell
* what happened to our children.
*/
signal(SIGCHLD, SIG_DFL);
if (is_url(url_orig))
url = url_decode(url_orig);
else
url = xstrdup(url_orig);
host = strstr(url, "://");
if (host) {
*host = '\0';
protocol = get_protocol(url);
host += 3;
c = '/';
} else {
host = url;
c = ':';
}
/*
* Don't do destructive transforms with git:// as that
* protocol code does '[]' unwrapping of its own.
*/
if (host[0] == '[') {
end = strchr(host + 1, ']');
if (end) {
if (protocol != PROTO_GIT) {
*end = 0;
host++;
}
end++;
} else
end = host;
} else
end = host;
path = strchr(end, c);
if (path && !has_dos_drive_prefix(end)) {
if (c == ':') {
if (host != url || path < strchrnul(host, '/')) {
protocol = PROTO_SSH;
*path++ = '\0';
} else /* '/' in the host part, assume local path */
path = end;
}
} else
path = end;
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';
}
/*
* Add support for ssh port: ssh://host.xy:<port>/...
*/
if (protocol == PROTO_SSH && host != url)
port = get_port(end);
if (protocol == PROTO_GIT) {
/* These underlying connection commands die() if they
* cannot connect.
*/
char *target_host = xstrdup(host);
if (git_use_proxy(host))
conn = git_proxy_connect(fd, host);
else
git_tcp_connect(fd, host, flags);
/*
* Separate original protocol components prog and path
* from extended host header with a NUL byte.
*
* Note: Do not add any other headers here! Doing so
* will cause older git-daemon servers to crash.
*/
packet_write(fd[1],
"%s %s%chost=%s%c",
prog, path, 0,
target_host, 0);
free(target_host);
free(url);
if (free_path)
free(path);
return conn;
}
conn = xcalloc(1, sizeof(*conn));
strbuf_init(&cmd, MAX_CMD_LEN);
strbuf_addstr(&cmd, prog);
strbuf_addch(&cmd, ' ');
sq_quote_buf(&cmd, path);
if (cmd.len >= MAX_CMD_LEN)
die("command line too long");
conn->in = conn->out = -1;
conn->argv = arg = xcalloc(7, sizeof(*arg));
if (protocol == PROTO_SSH) {
const char *ssh = getenv("GIT_SSH");
int putty = ssh && strcasestr(ssh, "plink");
if (!ssh) ssh = "ssh";
*arg++ = ssh;
if (putty && !strcasestr(ssh, "tortoiseplink"))
*arg++ = "-batch";
if (port) {
/* P is for PuTTY, p is for OpenSSH */
*arg++ = putty ? "-P" : "-p";
*arg++ = port;
}
*arg++ = host;
}
else {
/* remove repo-local variables from the environment */
conn->env = local_repo_env;
conn->use_shell = 1;
}
*arg++ = cmd.buf;
*arg = NULL;
if (start_command(conn))
die("unable to fork");
fd[0] = conn->out; /* read from child's stdout */
fd[1] = conn->in; /* write to child's stdin */
strbuf_release(&cmd);
free(url);
if (free_path)
free(path);
return conn;
}
int git_connection_is_socket(struct child_process *conn)
{
return conn == &no_fork;
}
int finish_connect(struct child_process *conn)
{
int code;
if (!conn || git_connection_is_socket(conn))
return 0;
code = finish_command(conn);
free(conn->argv);
free(conn);
return code;
}