Sync with maint
[git] / connect.c
1 #include "git-compat-util.h"
2 #include "cache.h"
3 #include "pkt-line.h"
4 #include "quote.h"
5 #include "refs.h"
6 #include "run-command.h"
7 #include "remote.h"
8 #include "connect.h"
9 #include "url.h"
10 #include "string-list.h"
11 #include "sha1-array.h"
12 #include "transport.h"
13
14 static char *server_capabilities;
15 static const char *parse_feature_value(const char *, const char *, int *);
16
17 static int check_ref(const char *name, unsigned int flags)
18 {
19         if (!flags)
20                 return 1;
21
22         if (!skip_prefix(name, "refs/", &name))
23                 return 0;
24
25         /* REF_NORMAL means that we don't want the magic fake tag refs */
26         if ((flags & REF_NORMAL) && check_refname_format(name, 0))
27                 return 0;
28
29         /* REF_HEADS means that we want regular branch heads */
30         if ((flags & REF_HEADS) && starts_with(name, "heads/"))
31                 return 1;
32
33         /* REF_TAGS means that we want tags */
34         if ((flags & REF_TAGS) && starts_with(name, "tags/"))
35                 return 1;
36
37         /* All type bits clear means that we are ok with anything */
38         return !(flags & ~REF_NORMAL);
39 }
40
41 int check_ref_type(const struct ref *ref, int flags)
42 {
43         return check_ref(ref->name, flags);
44 }
45
46 static void die_initial_contact(int got_at_least_one_head)
47 {
48         if (got_at_least_one_head)
49                 die("The remote end hung up upon initial contact");
50         else
51                 die("Could not read from remote repository.\n\n"
52                     "Please make sure you have the correct access rights\n"
53                     "and the repository exists.");
54 }
55
56 static void parse_one_symref_info(struct string_list *symref, const char *val, int len)
57 {
58         char *sym, *target;
59         struct string_list_item *item;
60
61         if (!len)
62                 return; /* just "symref" */
63         /* e.g. "symref=HEAD:refs/heads/master" */
64         sym = xmemdupz(val, len);
65         target = strchr(sym, ':');
66         if (!target)
67                 /* just "symref=something" */
68                 goto reject;
69         *(target++) = '\0';
70         if (check_refname_format(sym, REFNAME_ALLOW_ONELEVEL) ||
71             check_refname_format(target, REFNAME_ALLOW_ONELEVEL))
72                 /* "symref=bogus:pair */
73                 goto reject;
74         item = string_list_append(symref, sym);
75         item->util = target;
76         return;
77 reject:
78         free(sym);
79         return;
80 }
81
82 static void annotate_refs_with_symref_info(struct ref *ref)
83 {
84         struct string_list symref = STRING_LIST_INIT_DUP;
85         const char *feature_list = server_capabilities;
86
87         while (feature_list) {
88                 int len;
89                 const char *val;
90
91                 val = parse_feature_value(feature_list, "symref", &len);
92                 if (!val)
93                         break;
94                 parse_one_symref_info(&symref, val, len);
95                 feature_list = val + 1;
96         }
97         string_list_sort(&symref);
98
99         for (; ref; ref = ref->next) {
100                 struct string_list_item *item;
101                 item = string_list_lookup(&symref, ref->name);
102                 if (!item)
103                         continue;
104                 ref->symref = xstrdup((char *)item->util);
105         }
106         string_list_clear(&symref, 0);
107 }
108
109 /*
110  * Read all the refs from the other end
111  */
112 struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
113                               struct ref **list, unsigned int flags,
114                               struct sha1_array *extra_have,
115                               struct sha1_array *shallow_points)
116 {
117         struct ref **orig_list = list;
118         int got_at_least_one_head = 0;
119
120         *list = NULL;
121         for (;;) {
122                 struct ref *ref;
123                 unsigned char old_sha1[20];
124                 char *name;
125                 int len, name_len;
126                 char *buffer = packet_buffer;
127                 const char *arg;
128
129                 len = packet_read(in, &src_buf, &src_len,
130                                   packet_buffer, sizeof(packet_buffer),
131                                   PACKET_READ_GENTLE_ON_EOF |
132                                   PACKET_READ_CHOMP_NEWLINE);
133                 if (len < 0)
134                         die_initial_contact(got_at_least_one_head);
135
136                 if (!len)
137                         break;
138
139                 if (len > 4 && skip_prefix(buffer, "ERR ", &arg))
140                         die("remote error: %s", arg);
141
142                 if (len == 48 && skip_prefix(buffer, "shallow ", &arg)) {
143                         if (get_sha1_hex(arg, old_sha1))
144                                 die("protocol error: expected shallow sha-1, got '%s'", arg);
145                         if (!shallow_points)
146                                 die("repository on the other end cannot be shallow");
147                         sha1_array_append(shallow_points, old_sha1);
148                         continue;
149                 }
150
151                 if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
152                         die("protocol error: expected sha/ref, got '%s'", buffer);
153                 name = buffer + 41;
154
155                 name_len = strlen(name);
156                 if (len != name_len + 41) {
157                         free(server_capabilities);
158                         server_capabilities = xstrdup(name + name_len + 1);
159                 }
160
161                 if (extra_have && !strcmp(name, ".have")) {
162                         sha1_array_append(extra_have, old_sha1);
163                         continue;
164                 }
165
166                 if (!check_ref(name, flags))
167                         continue;
168                 ref = alloc_ref(buffer + 41);
169                 hashcpy(ref->old_sha1, old_sha1);
170                 *list = ref;
171                 list = &ref->next;
172                 got_at_least_one_head = 1;
173         }
174
175         annotate_refs_with_symref_info(*orig_list);
176
177         return list;
178 }
179
180 static const char *parse_feature_value(const char *feature_list, const char *feature, int *lenp)
181 {
182         int len;
183
184         if (!feature_list)
185                 return NULL;
186
187         len = strlen(feature);
188         while (*feature_list) {
189                 const char *found = strstr(feature_list, feature);
190                 if (!found)
191                         return NULL;
192                 if (feature_list == found || isspace(found[-1])) {
193                         const char *value = found + len;
194                         /* feature with no value (e.g., "thin-pack") */
195                         if (!*value || isspace(*value)) {
196                                 if (lenp)
197                                         *lenp = 0;
198                                 return value;
199                         }
200                         /* feature with a value (e.g., "agent=git/1.2.3") */
201                         else if (*value == '=') {
202                                 value++;
203                                 if (lenp)
204                                         *lenp = strcspn(value, " \t\n");
205                                 return value;
206                         }
207                         /*
208                          * otherwise we matched a substring of another feature;
209                          * keep looking
210                          */
211                 }
212                 feature_list = found + 1;
213         }
214         return NULL;
215 }
216
217 int parse_feature_request(const char *feature_list, const char *feature)
218 {
219         return !!parse_feature_value(feature_list, feature, NULL);
220 }
221
222 const char *server_feature_value(const char *feature, int *len)
223 {
224         return parse_feature_value(server_capabilities, feature, len);
225 }
226
227 int server_supports(const char *feature)
228 {
229         return !!server_feature_value(feature, NULL);
230 }
231
232 enum protocol {
233         PROTO_LOCAL = 1,
234         PROTO_FILE,
235         PROTO_SSH,
236         PROTO_GIT
237 };
238
239 int url_is_local_not_ssh(const char *url)
240 {
241         const char *colon = strchr(url, ':');
242         const char *slash = strchr(url, '/');
243         return !colon || (slash && slash < colon) ||
244                 has_dos_drive_prefix(url);
245 }
246
247 static const char *prot_name(enum protocol protocol)
248 {
249         switch (protocol) {
250                 case PROTO_LOCAL:
251                 case PROTO_FILE:
252                         return "file";
253                 case PROTO_SSH:
254                         return "ssh";
255                 case PROTO_GIT:
256                         return "git";
257                 default:
258                         return "unknown protocol";
259         }
260 }
261
262 static enum protocol get_protocol(const char *name)
263 {
264         if (!strcmp(name, "ssh"))
265                 return PROTO_SSH;
266         if (!strcmp(name, "git"))
267                 return PROTO_GIT;
268         if (!strcmp(name, "git+ssh"))
269                 return PROTO_SSH;
270         if (!strcmp(name, "ssh+git"))
271                 return PROTO_SSH;
272         if (!strcmp(name, "file"))
273                 return PROTO_FILE;
274         die("I don't handle protocol '%s'", name);
275 }
276
277 static char *host_end(char **hoststart, int removebrackets)
278 {
279         char *host = *hoststart;
280         char *end;
281         char *start = strstr(host, "@[");
282         if (start)
283                 start++; /* Jump over '@' */
284         else
285                 start = host;
286         if (start[0] == '[') {
287                 end = strchr(start + 1, ']');
288                 if (end) {
289                         if (removebrackets) {
290                                 *end = 0;
291                                 memmove(start, start + 1, end - start);
292                                 end++;
293                         }
294                 } else
295                         end = host;
296         } else
297                 end = host;
298         return end;
299 }
300
301 #define STR_(s) # s
302 #define STR(s)  STR_(s)
303
304 static void get_host_and_port(char **host, const char **port)
305 {
306         char *colon, *end;
307         end = host_end(host, 1);
308         colon = strchr(end, ':');
309         if (colon) {
310                 long portnr = strtol(colon + 1, &end, 10);
311                 if (end != colon + 1 && *end == '\0' && 0 <= portnr && portnr < 65536) {
312                         *colon = 0;
313                         *port = colon + 1;
314                 } else if (!colon[1]) {
315                         *colon = 0;
316                 }
317         }
318 }
319
320 static void enable_keepalive(int sockfd)
321 {
322         int ka = 1;
323
324         if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
325                 fprintf(stderr, "unable to set SO_KEEPALIVE on socket: %s\n",
326                         strerror(errno));
327 }
328
329 #ifndef NO_IPV6
330
331 static const char *ai_name(const struct addrinfo *ai)
332 {
333         static char addr[NI_MAXHOST];
334         if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
335                         NI_NUMERICHOST) != 0)
336                 xsnprintf(addr, sizeof(addr), "(unknown)");
337
338         return addr;
339 }
340
341 /*
342  * Returns a connected socket() fd, or else die()s.
343  */
344 static int git_tcp_connect_sock(char *host, int flags)
345 {
346         struct strbuf error_message = STRBUF_INIT;
347         int sockfd = -1;
348         const char *port = STR(DEFAULT_GIT_PORT);
349         struct addrinfo hints, *ai0, *ai;
350         int gai;
351         int cnt = 0;
352
353         get_host_and_port(&host, &port);
354         if (!*port)
355                 port = "<none>";
356
357         memset(&hints, 0, sizeof(hints));
358         hints.ai_socktype = SOCK_STREAM;
359         hints.ai_protocol = IPPROTO_TCP;
360
361         if (flags & CONNECT_VERBOSE)
362                 fprintf(stderr, "Looking up %s ... ", host);
363
364         gai = getaddrinfo(host, port, &hints, &ai);
365         if (gai)
366                 die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
367
368         if (flags & CONNECT_VERBOSE)
369                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
370
371         for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
372                 sockfd = socket(ai->ai_family,
373                                 ai->ai_socktype, ai->ai_protocol);
374                 if ((sockfd < 0) ||
375                     (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
376                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
377                                     host, cnt, ai_name(ai), strerror(errno));
378                         if (0 <= sockfd)
379                                 close(sockfd);
380                         sockfd = -1;
381                         continue;
382                 }
383                 if (flags & CONNECT_VERBOSE)
384                         fprintf(stderr, "%s ", ai_name(ai));
385                 break;
386         }
387
388         freeaddrinfo(ai0);
389
390         if (sockfd < 0)
391                 die("unable to connect to %s:\n%s", host, error_message.buf);
392
393         enable_keepalive(sockfd);
394
395         if (flags & CONNECT_VERBOSE)
396                 fprintf(stderr, "done.\n");
397
398         strbuf_release(&error_message);
399
400         return sockfd;
401 }
402
403 #else /* NO_IPV6 */
404
405 /*
406  * Returns a connected socket() fd, or else die()s.
407  */
408 static int git_tcp_connect_sock(char *host, int flags)
409 {
410         struct strbuf error_message = STRBUF_INIT;
411         int sockfd = -1;
412         const char *port = STR(DEFAULT_GIT_PORT);
413         char *ep;
414         struct hostent *he;
415         struct sockaddr_in sa;
416         char **ap;
417         unsigned int nport;
418         int cnt;
419
420         get_host_and_port(&host, &port);
421
422         if (flags & CONNECT_VERBOSE)
423                 fprintf(stderr, "Looking up %s ... ", host);
424
425         he = gethostbyname(host);
426         if (!he)
427                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
428         nport = strtoul(port, &ep, 10);
429         if ( ep == port || *ep ) {
430                 /* Not numeric */
431                 struct servent *se = getservbyname(port,"tcp");
432                 if ( !se )
433                         die("Unknown port %s", port);
434                 nport = se->s_port;
435         }
436
437         if (flags & CONNECT_VERBOSE)
438                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
439
440         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
441                 memset(&sa, 0, sizeof sa);
442                 sa.sin_family = he->h_addrtype;
443                 sa.sin_port = htons(nport);
444                 memcpy(&sa.sin_addr, *ap, he->h_length);
445
446                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
447                 if ((sockfd < 0) ||
448                     connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
449                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
450                                 host,
451                                 cnt,
452                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
453                                 strerror(errno));
454                         if (0 <= sockfd)
455                                 close(sockfd);
456                         sockfd = -1;
457                         continue;
458                 }
459                 if (flags & CONNECT_VERBOSE)
460                         fprintf(stderr, "%s ",
461                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
462                 break;
463         }
464
465         if (sockfd < 0)
466                 die("unable to connect to %s:\n%s", host, error_message.buf);
467
468         enable_keepalive(sockfd);
469
470         if (flags & CONNECT_VERBOSE)
471                 fprintf(stderr, "done.\n");
472
473         return sockfd;
474 }
475
476 #endif /* NO_IPV6 */
477
478
479 static void git_tcp_connect(int fd[2], char *host, int flags)
480 {
481         int sockfd = git_tcp_connect_sock(host, flags);
482
483         fd[0] = sockfd;
484         fd[1] = dup(sockfd);
485 }
486
487
488 static char *git_proxy_command;
489
490 static int git_proxy_command_options(const char *var, const char *value,
491                 void *cb)
492 {
493         if (!strcmp(var, "core.gitproxy")) {
494                 const char *for_pos;
495                 int matchlen = -1;
496                 int hostlen;
497                 const char *rhost_name = cb;
498                 int rhost_len = strlen(rhost_name);
499
500                 if (git_proxy_command)
501                         return 0;
502                 if (!value)
503                         return config_error_nonbool(var);
504                 /* [core]
505                  * ;# matches www.kernel.org as well
506                  * gitproxy = netcatter-1 for kernel.org
507                  * gitproxy = netcatter-2 for sample.xz
508                  * gitproxy = netcatter-default
509                  */
510                 for_pos = strstr(value, " for ");
511                 if (!for_pos)
512                         /* matches everybody */
513                         matchlen = strlen(value);
514                 else {
515                         hostlen = strlen(for_pos + 5);
516                         if (rhost_len < hostlen)
517                                 matchlen = -1;
518                         else if (!strncmp(for_pos + 5,
519                                           rhost_name + rhost_len - hostlen,
520                                           hostlen) &&
521                                  ((rhost_len == hostlen) ||
522                                   rhost_name[rhost_len - hostlen -1] == '.'))
523                                 matchlen = for_pos - value;
524                         else
525                                 matchlen = -1;
526                 }
527                 if (0 <= matchlen) {
528                         /* core.gitproxy = none for kernel.org */
529                         if (matchlen == 4 &&
530                             !memcmp(value, "none", 4))
531                                 matchlen = 0;
532                         git_proxy_command = xmemdupz(value, matchlen);
533                 }
534                 return 0;
535         }
536
537         return git_default_config(var, value, cb);
538 }
539
540 static int git_use_proxy(const char *host)
541 {
542         git_proxy_command = getenv("GIT_PROXY_COMMAND");
543         git_config(git_proxy_command_options, (void*)host);
544         return (git_proxy_command && *git_proxy_command);
545 }
546
547 static struct child_process *git_proxy_connect(int fd[2], char *host)
548 {
549         const char *port = STR(DEFAULT_GIT_PORT);
550         struct child_process *proxy;
551
552         get_host_and_port(&host, &port);
553
554         proxy = xmalloc(sizeof(*proxy));
555         child_process_init(proxy);
556         argv_array_push(&proxy->args, git_proxy_command);
557         argv_array_push(&proxy->args, host);
558         argv_array_push(&proxy->args, port);
559         proxy->in = -1;
560         proxy->out = -1;
561         if (start_command(proxy))
562                 die("cannot start proxy %s", git_proxy_command);
563         fd[0] = proxy->out; /* read from proxy stdout */
564         fd[1] = proxy->in;  /* write to proxy stdin */
565         return proxy;
566 }
567
568 static char *get_port(char *host)
569 {
570         char *end;
571         char *p = strchr(host, ':');
572
573         if (p) {
574                 long port = strtol(p + 1, &end, 10);
575                 if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
576                         *p = '\0';
577                         return p+1;
578                 }
579         }
580
581         return NULL;
582 }
583
584 /*
585  * Extract protocol and relevant parts from the specified connection URL.
586  * The caller must free() the returned strings.
587  */
588 static enum protocol parse_connect_url(const char *url_orig, char **ret_host,
589                                        char **ret_path)
590 {
591         char *url;
592         char *host, *path;
593         char *end;
594         int separator = '/';
595         enum protocol protocol = PROTO_LOCAL;
596
597         if (is_url(url_orig))
598                 url = url_decode(url_orig);
599         else
600                 url = xstrdup(url_orig);
601
602         host = strstr(url, "://");
603         if (host) {
604                 *host = '\0';
605                 protocol = get_protocol(url);
606                 host += 3;
607         } else {
608                 host = url;
609                 if (!url_is_local_not_ssh(url)) {
610                         protocol = PROTO_SSH;
611                         separator = ':';
612                 }
613         }
614
615         /*
616          * Don't do destructive transforms as protocol code does
617          * '[]' unwrapping in get_host_and_port()
618          */
619         end = host_end(&host, 0);
620
621         if (protocol == PROTO_LOCAL)
622                 path = end;
623         else if (protocol == PROTO_FILE && has_dos_drive_prefix(end))
624                 path = end; /* "file://$(pwd)" may be "file://C:/projects/repo" */
625         else
626                 path = strchr(end, separator);
627
628         if (!path || !*path)
629                 die("No path specified. See 'man git-pull' for valid url syntax");
630
631         /*
632          * null-terminate hostname and point path to ~ for URL's like this:
633          *    ssh://host.xz/~user/repo
634          */
635
636         end = path; /* Need to \0 terminate host here */
637         if (separator == ':')
638                 path++; /* path starts after ':' */
639         if (protocol == PROTO_GIT || protocol == PROTO_SSH) {
640                 if (path[1] == '~')
641                         path++;
642         }
643
644         path = xstrdup(path);
645         *end = '\0';
646
647         *ret_host = xstrdup(host);
648         *ret_path = path;
649         free(url);
650         return protocol;
651 }
652
653 static struct child_process no_fork = CHILD_PROCESS_INIT;
654
655 /*
656  * This returns a dummy child_process if the transport protocol does not
657  * need fork(2), or a struct child_process object if it does.  Once done,
658  * finish the connection with finish_connect() with the value returned from
659  * this function (it is safe to call finish_connect() with NULL to support
660  * the former case).
661  *
662  * If it returns, the connect is successful; it just dies on errors (this
663  * will hopefully be changed in a libification effort, to return NULL when
664  * the connection failed).
665  */
666 struct child_process *git_connect(int fd[2], const char *url,
667                                   const char *prog, int flags)
668 {
669         char *hostandport, *path;
670         struct child_process *conn = &no_fork;
671         enum protocol protocol;
672         struct strbuf cmd = STRBUF_INIT;
673
674         /* Without this we cannot rely on waitpid() to tell
675          * what happened to our children.
676          */
677         signal(SIGCHLD, SIG_DFL);
678
679         protocol = parse_connect_url(url, &hostandport, &path);
680         if ((flags & CONNECT_DIAG_URL) && (protocol != PROTO_SSH)) {
681                 printf("Diag: url=%s\n", url ? url : "NULL");
682                 printf("Diag: protocol=%s\n", prot_name(protocol));
683                 printf("Diag: hostandport=%s\n", hostandport ? hostandport : "NULL");
684                 printf("Diag: path=%s\n", path ? path : "NULL");
685                 conn = NULL;
686         } else if (protocol == PROTO_GIT) {
687                 /*
688                  * Set up virtual host information based on where we will
689                  * connect, unless the user has overridden us in
690                  * the environment.
691                  */
692                 char *target_host = getenv("GIT_OVERRIDE_VIRTUAL_HOST");
693                 if (target_host)
694                         target_host = xstrdup(target_host);
695                 else
696                         target_host = xstrdup(hostandport);
697
698                 transport_check_allowed("git");
699
700                 /* These underlying connection commands die() if they
701                  * cannot connect.
702                  */
703                 if (git_use_proxy(hostandport))
704                         conn = git_proxy_connect(fd, hostandport);
705                 else
706                         git_tcp_connect(fd, hostandport, flags);
707                 /*
708                  * Separate original protocol components prog and path
709                  * from extended host header with a NUL byte.
710                  *
711                  * Note: Do not add any other headers here!  Doing so
712                  * will cause older git-daemon servers to crash.
713                  */
714                 packet_write(fd[1],
715                              "%s %s%chost=%s%c",
716                              prog, path, 0,
717                              target_host, 0);
718                 free(target_host);
719         } else {
720                 conn = xmalloc(sizeof(*conn));
721                 child_process_init(conn);
722
723                 strbuf_addstr(&cmd, prog);
724                 strbuf_addch(&cmd, ' ');
725                 sq_quote_buf(&cmd, path);
726
727                 /* remove repo-local variables from the environment */
728                 conn->env = local_repo_env;
729                 conn->use_shell = 1;
730                 conn->in = conn->out = -1;
731                 if (protocol == PROTO_SSH) {
732                         const char *ssh;
733                         int putty = 0, tortoiseplink = 0;
734                         char *ssh_host = hostandport;
735                         const char *port = NULL;
736                         transport_check_allowed("ssh");
737                         get_host_and_port(&ssh_host, &port);
738
739                         if (!port)
740                                 port = get_port(ssh_host);
741
742                         if (flags & CONNECT_DIAG_URL) {
743                                 printf("Diag: url=%s\n", url ? url : "NULL");
744                                 printf("Diag: protocol=%s\n", prot_name(protocol));
745                                 printf("Diag: userandhost=%s\n", ssh_host ? ssh_host : "NULL");
746                                 printf("Diag: port=%s\n", port ? port : "NONE");
747                                 printf("Diag: path=%s\n", path ? path : "NULL");
748
749                                 free(hostandport);
750                                 free(path);
751                                 free(conn);
752                                 return NULL;
753                         }
754
755                         ssh = getenv("GIT_SSH_COMMAND");
756                         if (!ssh) {
757                                 const char *base;
758                                 char *ssh_dup;
759
760                                 /*
761                                  * GIT_SSH is the no-shell version of
762                                  * GIT_SSH_COMMAND (and must remain so for
763                                  * historical compatibility).
764                                  */
765                                 conn->use_shell = 0;
766
767                                 ssh = getenv("GIT_SSH");
768                                 if (!ssh)
769                                         ssh = "ssh";
770
771                                 ssh_dup = xstrdup(ssh);
772                                 base = basename(ssh_dup);
773
774                                 tortoiseplink = !strcasecmp(base, "tortoiseplink") ||
775                                         !strcasecmp(base, "tortoiseplink.exe");
776                                 putty = tortoiseplink ||
777                                         !strcasecmp(base, "plink") ||
778                                         !strcasecmp(base, "plink.exe");
779
780                                 free(ssh_dup);
781                         }
782
783                         argv_array_push(&conn->args, ssh);
784                         if (tortoiseplink)
785                                 argv_array_push(&conn->args, "-batch");
786                         if (port) {
787                                 /* P is for PuTTY, p is for OpenSSH */
788                                 argv_array_push(&conn->args, putty ? "-P" : "-p");
789                                 argv_array_push(&conn->args, port);
790                         }
791                         argv_array_push(&conn->args, ssh_host);
792                 } else {
793                         transport_check_allowed("file");
794                 }
795                 argv_array_push(&conn->args, cmd.buf);
796
797                 if (start_command(conn))
798                         die("unable to fork");
799
800                 fd[0] = conn->out; /* read from child's stdout */
801                 fd[1] = conn->in;  /* write to child's stdin */
802                 strbuf_release(&cmd);
803         }
804         free(hostandport);
805         free(path);
806         return conn;
807 }
808
809 int git_connection_is_socket(struct child_process *conn)
810 {
811         return conn == &no_fork;
812 }
813
814 int finish_connect(struct child_process *conn)
815 {
816         int code;
817         if (!conn || git_connection_is_socket(conn))
818                 return 0;
819
820         code = finish_command(conn);
821         free(conn);
822         return code;
823 }