git/connect.c
Masaya Suzuki 2d103c31c2 pack-protocol.txt: accept error packets in any context
In the Git pack protocol definition, an error packet may appear only in
a certain context. However, servers can face a runtime error (e.g. I/O
error) at an arbitrary timing. This patch changes the protocol to allow
an error packet to be sent instead of any packet.

Without this protocol spec change, when a server cannot process a
request, there's no way to tell that to a client. Since the server
cannot produce a valid response, it would be forced to cut a connection
without telling why. With this protocol spec change, the server can be
more gentle in this situation. An old client may see these error packets
as an unexpected packet, but this is not worse than having an unexpected
EOF.

Following this protocol spec change, the error packet handling code is
moved to pkt-line.c. Implementation wise, this implementation uses
pkt-line to communicate with a subprocess. Since this is not a part of
Git protocol, it's possible that a packet that is not supposed to be an
error packet is mistakenly parsed as an error packet. This error packet
handling is enabled only for the Git pack protocol parsing code
considering this.

Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-02 13:05:30 -08:00

1325 lines
32 KiB
C

#include "git-compat-util.h"
#include "cache.h"
#include "config.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"
#include "transport.h"
#include "strbuf.h"
#include "version.h"
#include "protocol.h"
#include "alias.h"
static char *server_capabilities_v1;
static struct argv_array server_capabilities_v2 = ARGV_ARRAY_INIT;
static const char *parse_feature_value(const char *, const char *, int *);
static int check_ref(const char *name, unsigned int flags)
{
if (!flags)
return 1;
if (!skip_prefix(name, "refs/", &name))
return 0;
/* 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) && starts_with(name, "heads/"))
return 1;
/* REF_TAGS means that we want tags */
if ((flags & REF_TAGS) && starts_with(name, "tags/"))
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, flags);
}
static NORETURN void die_initial_contact(int unexpected)
{
/*
* A hang-up after seeing some response from the other end
* means that it is unexpected, as we know the other end is
* willing to talk to us. A hang-up before seeing any
* response does not necessarily mean an ACL problem, though.
*/
if (unexpected)
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."));
}
/* Checks if the server supports the capability 'c' */
int server_supports_v2(const char *c, int die_on_error)
{
int i;
for (i = 0; i < server_capabilities_v2.argc; i++) {
const char *out;
if (skip_prefix(server_capabilities_v2.argv[i], c, &out) &&
(!*out || *out == '='))
return 1;
}
if (die_on_error)
die(_("server doesn't support '%s'"), c);
return 0;
}
int server_supports_feature(const char *c, const char *feature,
int die_on_error)
{
int i;
for (i = 0; i < server_capabilities_v2.argc; i++) {
const char *out;
if (skip_prefix(server_capabilities_v2.argv[i], c, &out) &&
(!*out || *(out++) == '=')) {
if (parse_feature_request(out, feature))
return 1;
else
break;
}
}
if (die_on_error)
die(_("server doesn't support feature '%s'"), feature);
return 0;
}
static void process_capabilities_v2(struct packet_reader *reader)
{
while (packet_reader_read(reader) == PACKET_READ_NORMAL)
argv_array_push(&server_capabilities_v2, reader->line);
if (reader->status != PACKET_READ_FLUSH)
die(_("expected flush after capabilities"));
}
enum protocol_version discover_version(struct packet_reader *reader)
{
enum protocol_version version = protocol_unknown_version;
/*
* Peek the first line of the server's response to
* determine the protocol version the server is speaking.
*/
switch (packet_reader_peek(reader)) {
case PACKET_READ_EOF:
die_initial_contact(0);
case PACKET_READ_FLUSH:
case PACKET_READ_DELIM:
version = protocol_v0;
break;
case PACKET_READ_NORMAL:
version = determine_protocol_version_client(reader->line);
break;
}
switch (version) {
case protocol_v2:
process_capabilities_v2(reader);
break;
case protocol_v1:
/* Read the peeked version line */
packet_reader_read(reader);
break;
case protocol_v0:
break;
case protocol_unknown_version:
BUG("unknown protocol version");
}
return version;
}
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 = xmemdupz(val, len);
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_nodup(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_v1;
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;
}
string_list_sort(&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);
}
static void process_capabilities(const char *line, int *len)
{
int nul_location = strlen(line);
if (nul_location == *len)
return;
server_capabilities_v1 = xstrdup(line + nul_location + 1);
*len = nul_location;
}
static int process_dummy_ref(const char *line)
{
struct object_id oid;
const char *name;
if (parse_oid_hex(line, &oid, &name))
return 0;
if (*name != ' ')
return 0;
name++;
return oideq(&null_oid, &oid) && !strcmp(name, "capabilities^{}");
}
static void check_no_capabilities(const char *line, int len)
{
if (strlen(line) != len)
warning(_("ignoring capabilities after first line '%s'"),
line + strlen(line));
}
static int process_ref(const char *line, int len, struct ref ***list,
unsigned int flags, struct oid_array *extra_have)
{
struct object_id old_oid;
const char *name;
if (parse_oid_hex(line, &old_oid, &name))
return 0;
if (*name != ' ')
return 0;
name++;
if (extra_have && !strcmp(name, ".have")) {
oid_array_append(extra_have, &old_oid);
} else if (!strcmp(name, "capabilities^{}")) {
die(_("protocol error: unexpected capabilities^{}"));
} else if (check_ref(name, flags)) {
struct ref *ref = alloc_ref(name);
oidcpy(&ref->old_oid, &old_oid);
**list = ref;
*list = &ref->next;
}
check_no_capabilities(line, len);
return 1;
}
static int process_shallow(const char *line, int len,
struct oid_array *shallow_points)
{
const char *arg;
struct object_id old_oid;
if (!skip_prefix(line, "shallow ", &arg))
return 0;
if (get_oid_hex(arg, &old_oid))
die(_("protocol error: expected shallow sha-1, got '%s'"), arg);
if (!shallow_points)
die(_("repository on the other end cannot be shallow"));
oid_array_append(shallow_points, &old_oid);
check_no_capabilities(line, len);
return 1;
}
enum get_remote_heads_state {
EXPECTING_FIRST_REF = 0,
EXPECTING_REF,
EXPECTING_SHALLOW,
EXPECTING_DONE,
};
/*
* Read all the refs from the other end
*/
struct ref **get_remote_heads(struct packet_reader *reader,
struct ref **list, unsigned int flags,
struct oid_array *extra_have,
struct oid_array *shallow_points)
{
struct ref **orig_list = list;
int len = 0;
enum get_remote_heads_state state = EXPECTING_FIRST_REF;
*list = NULL;
while (state != EXPECTING_DONE) {
switch (packet_reader_read(reader)) {
case PACKET_READ_EOF:
die_initial_contact(1);
case PACKET_READ_NORMAL:
len = reader->pktlen;
break;
case PACKET_READ_FLUSH:
state = EXPECTING_DONE;
break;
case PACKET_READ_DELIM:
die(_("invalid packet"));
}
switch (state) {
case EXPECTING_FIRST_REF:
process_capabilities(reader->line, &len);
if (process_dummy_ref(reader->line)) {
state = EXPECTING_SHALLOW;
break;
}
state = EXPECTING_REF;
/* fallthrough */
case EXPECTING_REF:
if (process_ref(reader->line, len, &list, flags, extra_have))
break;
state = EXPECTING_SHALLOW;
/* fallthrough */
case EXPECTING_SHALLOW:
if (process_shallow(reader->line, len, shallow_points))
break;
die(_("protocol error: unexpected '%s'"), reader->line);
case EXPECTING_DONE:
break;
}
}
annotate_refs_with_symref_info(*orig_list);
return list;
}
/* Returns 1 when a valid ref has been added to `list`, 0 otherwise */
static int process_ref_v2(const char *line, struct ref ***list)
{
int ret = 1;
int i = 0;
struct object_id old_oid;
struct ref *ref;
struct string_list line_sections = STRING_LIST_INIT_DUP;
const char *end;
/*
* Ref lines have a number of fields which are space deliminated. The
* first field is the OID of the ref. The second field is the ref
* name. Subsequent fields (symref-target and peeled) are optional and
* don't have a particular order.
*/
if (string_list_split(&line_sections, line, ' ', -1) < 2) {
ret = 0;
goto out;
}
if (parse_oid_hex(line_sections.items[i++].string, &old_oid, &end) ||
*end) {
ret = 0;
goto out;
}
ref = alloc_ref(line_sections.items[i++].string);
oidcpy(&ref->old_oid, &old_oid);
**list = ref;
*list = &ref->next;
for (; i < line_sections.nr; i++) {
const char *arg = line_sections.items[i].string;
if (skip_prefix(arg, "symref-target:", &arg))
ref->symref = xstrdup(arg);
if (skip_prefix(arg, "peeled:", &arg)) {
struct object_id peeled_oid;
char *peeled_name;
struct ref *peeled;
if (parse_oid_hex(arg, &peeled_oid, &end) || *end) {
ret = 0;
goto out;
}
peeled_name = xstrfmt("%s^{}", ref->name);
peeled = alloc_ref(peeled_name);
oidcpy(&peeled->old_oid, &peeled_oid);
**list = peeled;
*list = &peeled->next;
free(peeled_name);
}
}
out:
string_list_clear(&line_sections, 0);
return ret;
}
struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
struct ref **list, int for_push,
const struct argv_array *ref_prefixes,
const struct string_list *server_options)
{
int i;
*list = NULL;
if (server_supports_v2("ls-refs", 1))
packet_write_fmt(fd_out, "command=ls-refs\n");
if (server_supports_v2("agent", 0))
packet_write_fmt(fd_out, "agent=%s", git_user_agent_sanitized());
if (server_options && server_options->nr &&
server_supports_v2("server-option", 1))
for (i = 0; i < server_options->nr; i++)
packet_write_fmt(fd_out, "server-option=%s",
server_options->items[i].string);
packet_delim(fd_out);
/* When pushing we don't want to request the peeled tags */
if (!for_push)
packet_write_fmt(fd_out, "peel\n");
packet_write_fmt(fd_out, "symrefs\n");
for (i = 0; ref_prefixes && i < ref_prefixes->argc; i++) {
packet_write_fmt(fd_out, "ref-prefix %s\n",
ref_prefixes->argv[i]);
}
packet_flush(fd_out);
/* Process response from server */
while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
if (!process_ref_v2(reader->line, &list))
die(_("invalid ls-refs response: %s"), reader->line);
}
if (reader->status != PACKET_READ_FLUSH)
die(_("expected flush after ref listing"));
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_v1, 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 "unknown 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")) /* deprecated - do not use */
return PROTO_SSH;
if (!strcmp(name, "ssh+git")) /* deprecated - do not use */
return PROTO_SSH;
if (!strcmp(name, "file"))
return PROTO_FILE;
die(_("protocol '%s' is not supported"), name);
}
static char *host_end(char **hoststart, int removebrackets)
{
char *host = *hoststart;
char *end;
char *start = strstr(host, "@[");
if (start)
start++; /* Jump over '@' */
else
start = host;
if (start[0] == '[') {
end = strchr(start + 1, ']');
if (end) {
if (removebrackets) {
*end = 0;
memmove(start, start + 1, end - start);
end++;
}
} else
end = host;
} else
end = host;
return end;
}
#define STR_(s) # s
#define STR(s) STR_(s)
static void get_host_and_port(char **host, const char **port)
{
char *colon, *end;
end = host_end(host, 1);
colon = strchr(end, ':');
if (colon) {
long portnr = strtol(colon + 1, &end, 10);
if (end != colon + 1 && *end == '\0' && 0 <= portnr && portnr < 65536) {
*colon = 0;
*port = colon + 1;
} else if (!colon[1]) {
*colon = 0;
}
}
}
static void enable_keepalive(int sockfd)
{
int ka = 1;
if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
error_errno(_("unable to set SO_KEEPALIVE on socket"));
}
#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)
xsnprintf(addr, sizeof(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));
if (flags & CONNECT_IPV4)
hints.ai_family = AF_INET;
else if (flags & CONNECT_IPV6)
hints.ai_family = AF_INET6;
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)
/* TRANSLATORS: this is the end of "Looking up %s ... " */
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)
/* TRANSLATORS: this is the end of "Connecting to %s (port %s) ... " */
fprintf_ln(stderr, _("done."));
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)
/* TRANSLATORS: this is the end of "Looking up %s ... " */
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)
/* TRANSLATORS: this is the end of "Connecting to %s (port %s) ... " */
fprintf_ln(stderr, _("done."));
return sockfd;
}
#endif /* NO_IPV6 */
/*
* Dummy child_process returned by git_connect() if the transport protocol
* does not need fork(2).
*/
static struct child_process no_fork = CHILD_PROCESS_INIT;
int git_connection_is_socket(struct child_process *conn)
{
return conn == &no_fork;
}
static struct child_process *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);
return &no_fork;
}
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);
struct child_process *proxy;
get_host_and_port(&host, &port);
if (looks_like_command_line_option(host))
die(_("strange hostname '%s' blocked"), host);
if (looks_like_command_line_option(port))
die(_("strange port '%s' blocked"), port);
proxy = xmalloc(sizeof(*proxy));
child_process_init(proxy);
argv_array_push(&proxy->args, git_proxy_command);
argv_array_push(&proxy->args, host);
argv_array_push(&proxy->args, port);
proxy->in = -1;
proxy->out = -1;
if (start_command(proxy))
die(_("cannot start proxy %s"), git_proxy_command);
fd[0] = proxy->out; /* read from proxy stdout */
fd[1] = proxy->in; /* write to proxy stdin */
return proxy;
}
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;
}
/*
* 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, "://");
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()
*/
end = host_end(&host, 0);
if (protocol == PROTO_LOCAL)
path = end;
else if (protocol == PROTO_FILE && has_dos_drive_prefix(end))
path = end; /* "file://$(pwd)" may be "file://C:/projects/repo" */
else
path = strchr(end, separator);
if (!path || !*path)
die(_("no path specified; see 'git help pull' for valid url syntax"));
/*
* null-terminate hostname and point path to ~ for URL's like this:
* ssh://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 const char *get_ssh_command(void)
{
const char *ssh;
if ((ssh = getenv("GIT_SSH_COMMAND")))
return ssh;
if (!git_config_get_string_const("core.sshcommand", &ssh))
return ssh;
return NULL;
}
enum ssh_variant {
VARIANT_AUTO,
VARIANT_SIMPLE,
VARIANT_SSH,
VARIANT_PLINK,
VARIANT_PUTTY,
VARIANT_TORTOISEPLINK,
};
static void override_ssh_variant(enum ssh_variant *ssh_variant)
{
const char *variant = getenv("GIT_SSH_VARIANT");
if (!variant && git_config_get_string_const("ssh.variant", &variant))
return;
if (!strcmp(variant, "auto"))
*ssh_variant = VARIANT_AUTO;
else if (!strcmp(variant, "plink"))
*ssh_variant = VARIANT_PLINK;
else if (!strcmp(variant, "putty"))
*ssh_variant = VARIANT_PUTTY;
else if (!strcmp(variant, "tortoiseplink"))
*ssh_variant = VARIANT_TORTOISEPLINK;
else if (!strcmp(variant, "simple"))
*ssh_variant = VARIANT_SIMPLE;
else
*ssh_variant = VARIANT_SSH;
}
static enum ssh_variant determine_ssh_variant(const char *ssh_command,
int is_cmdline)
{
enum ssh_variant ssh_variant = VARIANT_AUTO;
const char *variant;
char *p = NULL;
override_ssh_variant(&ssh_variant);
if (ssh_variant != VARIANT_AUTO)
return ssh_variant;
if (!is_cmdline) {
p = xstrdup(ssh_command);
variant = basename(p);
} else {
const char **ssh_argv;
p = xstrdup(ssh_command);
if (split_cmdline(p, &ssh_argv) > 0) {
variant = basename((char *)ssh_argv[0]);
/*
* At this point, variant points into the buffer
* referenced by p, hence we do not need ssh_argv
* any longer.
*/
free(ssh_argv);
} else {
free(p);
return ssh_variant;
}
}
if (!strcasecmp(variant, "ssh") ||
!strcasecmp(variant, "ssh.exe"))
ssh_variant = VARIANT_SSH;
else if (!strcasecmp(variant, "plink") ||
!strcasecmp(variant, "plink.exe"))
ssh_variant = VARIANT_PLINK;
else if (!strcasecmp(variant, "tortoiseplink") ||
!strcasecmp(variant, "tortoiseplink.exe"))
ssh_variant = VARIANT_TORTOISEPLINK;
free(p);
return ssh_variant;
}
/*
* Open a connection using Git's native protocol.
*
* The caller is responsible for freeing hostandport, but this function may
* modify it (for example, to truncate it to remove the port part).
*/
static struct child_process *git_connect_git(int fd[2], char *hostandport,
const char *path, const char *prog,
enum protocol_version version,
int flags)
{
struct child_process *conn;
struct strbuf request = STRBUF_INIT;
/*
* Set up virtual host information based on where we will
* connect, unless the user has overridden us in
* the environment.
*/
char *target_host = getenv("GIT_OVERRIDE_VIRTUAL_HOST");
if (target_host)
target_host = xstrdup(target_host);
else
target_host = xstrdup(hostandport);
transport_check_allowed("git");
/*
* These underlying connection commands die() if they
* cannot connect.
*/
if (git_use_proxy(hostandport))
conn = git_proxy_connect(fd, hostandport);
else
conn = 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.
*/
strbuf_addf(&request,
"%s %s%chost=%s%c",
prog, path, 0,
target_host, 0);
/* If using a new version put that stuff here after a second null byte */
if (version > 0) {
strbuf_addch(&request, '\0');
strbuf_addf(&request, "version=%d%c",
version, '\0');
}
packet_write(fd[1], request.buf, request.len);
free(target_host);
strbuf_release(&request);
return conn;
}
/*
* Append the appropriate environment variables to `env` and options to
* `args` for running ssh in Git's SSH-tunneled transport.
*/
static void push_ssh_options(struct argv_array *args, struct argv_array *env,
enum ssh_variant variant, const char *port,
enum protocol_version version, int flags)
{
if (variant == VARIANT_SSH &&
version > 0) {
argv_array_push(args, "-o");
argv_array_push(args, "SendEnv=" GIT_PROTOCOL_ENVIRONMENT);
argv_array_pushf(env, GIT_PROTOCOL_ENVIRONMENT "=version=%d",
version);
}
if (flags & CONNECT_IPV4) {
switch (variant) {
case VARIANT_AUTO:
BUG("VARIANT_AUTO passed to push_ssh_options");
case VARIANT_SIMPLE:
die(_("ssh variant 'simple' does not support -4"));
case VARIANT_SSH:
case VARIANT_PLINK:
case VARIANT_PUTTY:
case VARIANT_TORTOISEPLINK:
argv_array_push(args, "-4");
}
} else if (flags & CONNECT_IPV6) {
switch (variant) {
case VARIANT_AUTO:
BUG("VARIANT_AUTO passed to push_ssh_options");
case VARIANT_SIMPLE:
die(_("ssh variant 'simple' does not support -6"));
case VARIANT_SSH:
case VARIANT_PLINK:
case VARIANT_PUTTY:
case VARIANT_TORTOISEPLINK:
argv_array_push(args, "-6");
}
}
if (variant == VARIANT_TORTOISEPLINK)
argv_array_push(args, "-batch");
if (port) {
switch (variant) {
case VARIANT_AUTO:
BUG("VARIANT_AUTO passed to push_ssh_options");
case VARIANT_SIMPLE:
die(_("ssh variant 'simple' does not support setting port"));
case VARIANT_SSH:
argv_array_push(args, "-p");
break;
case VARIANT_PLINK:
case VARIANT_PUTTY:
case VARIANT_TORTOISEPLINK:
argv_array_push(args, "-P");
}
argv_array_push(args, port);
}
}
/* Prepare a child_process for use by Git's SSH-tunneled transport. */
static void fill_ssh_args(struct child_process *conn, const char *ssh_host,
const char *port, enum protocol_version version,
int flags)
{
const char *ssh;
enum ssh_variant variant;
if (looks_like_command_line_option(ssh_host))
die(_("strange hostname '%s' blocked"), ssh_host);
ssh = get_ssh_command();
if (ssh) {
variant = determine_ssh_variant(ssh, 1);
} else {
/*
* GIT_SSH is the no-shell version of
* GIT_SSH_COMMAND (and must remain so for
* historical compatibility).
*/
conn->use_shell = 0;
ssh = getenv("GIT_SSH");
if (!ssh)
ssh = "ssh";
variant = determine_ssh_variant(ssh, 0);
}
if (variant == VARIANT_AUTO) {
struct child_process detect = CHILD_PROCESS_INIT;
detect.use_shell = conn->use_shell;
detect.no_stdin = detect.no_stdout = detect.no_stderr = 1;
argv_array_push(&detect.args, ssh);
argv_array_push(&detect.args, "-G");
push_ssh_options(&detect.args, &detect.env_array,
VARIANT_SSH, port, version, flags);
argv_array_push(&detect.args, ssh_host);
variant = run_command(&detect) ? VARIANT_SIMPLE : VARIANT_SSH;
}
argv_array_push(&conn->args, ssh);
push_ssh_options(&conn->args, &conn->env_array, variant, port, version, flags);
argv_array_push(&conn->args, ssh_host);
}
/*
* This returns the dummy child_process `no_fork` 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;
enum protocol protocol;
enum protocol_version version = get_protocol_version_config();
/*
* NEEDSWORK: If we are trying to use protocol v2 and we are planning
* to perform a push, then fallback to v0 since the client doesn't know
* how to push yet using v2.
*/
if (version == protocol_v2 && !strcmp("git-receive-pack", prog))
version = protocol_v0;
/* 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) && (protocol != PROTO_SSH)) {
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) {
conn = git_connect_git(fd, hostandport, path, prog, version, flags);
} else {
struct strbuf cmd = STRBUF_INIT;
const char *const *var;
conn = xmalloc(sizeof(*conn));
child_process_init(conn);
if (looks_like_command_line_option(path))
die(_("strange pathname '%s' blocked"), path);
strbuf_addstr(&cmd, prog);
strbuf_addch(&cmd, ' ');
sq_quote_buf(&cmd, path);
/* remove repo-local variables from the environment */
for (var = local_repo_env; *var; var++)
argv_array_push(&conn->env_array, *var);
conn->use_shell = 1;
conn->in = conn->out = -1;
if (protocol == PROTO_SSH) {
char *ssh_host = hostandport;
const char *port = NULL;
transport_check_allowed("ssh");
get_host_and_port(&ssh_host, &port);
if (!port)
port = get_port(ssh_host);
if (flags & CONNECT_DIAG_URL) {
printf("Diag: url=%s\n", url ? url : "NULL");
printf("Diag: protocol=%s\n", prot_name(protocol));
printf("Diag: userandhost=%s\n", ssh_host ? ssh_host : "NULL");
printf("Diag: port=%s\n", port ? port : "NONE");
printf("Diag: path=%s\n", path ? path : "NULL");
free(hostandport);
free(path);
free(conn);
strbuf_release(&cmd);
return NULL;
}
fill_ssh_args(conn, ssh_host, port, version, flags);
} else {
transport_check_allowed("file");
if (version > 0) {
argv_array_pushf(&conn->env_array, GIT_PROTOCOL_ENVIRONMENT "=version=%d",
version);
}
}
argv_array_push(&conn->args, cmd.buf);
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 finish_connect(struct child_process *conn)
{
int code;
if (!conn || git_connection_is_socket(conn))
return 0;
code = finish_command(conn);
free(conn);
return code;
}