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connect.c
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connect.c
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#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"
#include "sha1-array.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 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 sha1_array *extra_have,
struct sha1_array *shallow_points)
{
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 && starts_with(buffer, "ERR "))
die("remote error: %s", buffer + 4);
if (len == 48 && starts_with(buffer, "shallow ")) {
if (get_sha1_hex(buffer + 8, old_sha1))
die("protocol error: expected shallow sha-1, got '%s'", buffer + 8);
if (!shallow_points)
die("repository on the other end cannot be shallow");
sha1_array_append(shallow_points, old_sha1);
continue;
}
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)) {
sha1_array_append(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_FILE,
PROTO_SSH,
PROTO_GIT
};
int url_is_local_not_ssh(const char *url)
{
const char *colon = strchr(url, ':');
const char *slash = strchr(url, '/');
return !colon || (slash && slash < colon) ||
has_dos_drive_prefix(url);
}
static const char *prot_name(enum protocol protocol)
{
switch (protocol) {
case PROTO_LOCAL:
case PROTO_FILE:
return "file";
case PROTO_SSH:
return "ssh";
case PROTO_GIT:
return "git";
default:
return "unkown protocol";
}
}
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_FILE;
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;
}
static const char *get_port_numeric(const char *p)
{
char *end;
if (p) {
long port = strtol(p + 1, &end, 10);
if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
return p;
}
}
return NULL;
}
/*
* Extract protocol and relevant parts from the specified connection URL.
* The caller must free() the returned strings.
*/
static enum protocol parse_connect_url(const char *url_orig, char **ret_host,
char **ret_path)
{
char *url;
char *host, *path;
char *end;
int separator = '/';
enum protocol protocol = PROTO_LOCAL;
if (is_url(url_orig))
url = url_decode(url_orig);
else
url = xstrdup(url_orig);
host = strstr(url, ":https://");
if (host) {
*host = '\0';
protocol = get_protocol(url);
host += 3;
} else {
host = url;
if (!url_is_local_not_ssh(url)) {
protocol = PROTO_SSH;
separator = ':';
}
}
/*
* Don't do destructive transforms as protocol code does
* '[]' unwrapping in get_host_and_port()
*/
if (host[0] == '[') {
end = strchr(host + 1, ']');
if (end) {
end++;
} else
end = host;
} else
end = host;
if (protocol == PROTO_LOCAL)
path = end;
else if (protocol == PROTO_FILE && has_dos_drive_prefix(end))
path = end; /* "file:https://$(pwd)" may be "file:https://C:/projects/repo" */
else
path = strchr(end, separator);
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:https://host.xz/~user/repo
*/
end = path; /* Need to \0 terminate host here */
if (separator == ':')
path++; /* path starts after ':' */
if (protocol == PROTO_GIT || protocol == PROTO_SSH) {
if (path[1] == '~')
path++;
}
path = xstrdup(path);
*end = '\0';
*ret_host = xstrdup(host);
*ret_path = path;
free(url);
return protocol;
}
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,
const char *prog, int flags)
{
char *hostandport, *path;
struct child_process *conn = &no_fork;
enum protocol protocol;
const char **arg;
struct strbuf cmd = STRBUF_INIT;
/* Without this we cannot rely on waitpid() to tell
* what happened to our children.
*/
signal(SIGCHLD, SIG_DFL);
protocol = parse_connect_url(url, &hostandport, &path);
if (flags & CONNECT_DIAG_URL) {
printf("Diag: url=%s\n", url ? url : "NULL");
printf("Diag: protocol=%s\n", prot_name(protocol));
printf("Diag: hostandport=%s\n", hostandport ? hostandport : "NULL");
printf("Diag: path=%s\n", path ? path : "NULL");
conn = NULL;
} else if (protocol == PROTO_GIT) {
/* These underlying connection commands die() if they
* cannot connect.
*/
char *target_host = xstrdup(hostandport);
if (git_use_proxy(hostandport))
conn = git_proxy_connect(fd, hostandport);
else
git_tcp_connect(fd, hostandport, 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);
} else {
conn = xcalloc(1, sizeof(*conn));
strbuf_addstr(&cmd, prog);
strbuf_addch(&cmd, ' ');
sq_quote_buf(&cmd, path);
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");
char *ssh_host = hostandport;
const char *port = NULL;
get_host_and_port(&ssh_host, &port);
port = get_port_numeric(port);
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++ = ssh_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(hostandport);
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;
}