Andrew's git - gitweb.git/blob - builtin/remote-ext.c

   1#include "builtin.h"
   2#include "transport.h"
   3#include "run-command.h"
   4#include "pkt-line.h"
   5
   6static const char usage_msg[] =
   7        "git remote-ext <remote> <url>";
   8
   9/*
  10 * URL syntax:
  11 *      'command [arg1 [arg2 [...]]]'   Invoke command with given arguments.
  12 *      Special characters:
  13 *      '% ': Literal space in argument.
  14 *      '%%': Literal percent sign.
  15 *      '%S': Name of service (git-upload-pack/git-upload-archive/
  16 *              git-receive-pack.
  17 *      '%s': Same as \s, but with possible git- prefix stripped.
  18 *      '%G': Only allowed as first 'character' of argument. Do not pass this
  19 *              Argument to command, instead send this as name of repository
  20 *              in in-line git://-style request (also activates sending this
  21 *              style of request).
  22 *      '%V': Only allowed as first 'character' of argument. Used in
  23 *              conjunction with '%G': Do not pass this argument to command,
  24 *              instead send this as vhost in git://-style request (note: does
  25 *              not activate sending git:// style request).
  26 */
  27
  28static char *git_req;
  29static char *git_req_vhost;
  30
  31static char *strip_escapes(const char *str, const char *service,
  32        const char **next)
  33{
  34        size_t rpos = 0;
  35        int escape = 0;
  36        char special = 0;
  37        const char *service_noprefix = service;
  38        struct strbuf ret = STRBUF_INIT;
  39
  40        skip_prefix(service_noprefix, "git-", &service_noprefix);
  41
  42        /* Pass the service to command. */
  43        setenv("GIT_EXT_SERVICE", service, 1);
  44        setenv("GIT_EXT_SERVICE_NOPREFIX", service_noprefix, 1);
  45
  46        /* Scan the length of argument. */
  47        while (str[rpos] && (escape || str[rpos] != ' ')) {
  48                if (escape) {
  49                        switch (str[rpos]) {
  50                        case ' ':
  51                        case '%':
  52                        case 's':
  53                        case 'S':
  54                                break;
  55                        case 'G':
  56                        case 'V':
  57                                special = str[rpos];
  58                                if (rpos == 1)
  59                                        break;
  60                                /* fallthrough */
  61                        default:
  62                                die("Bad remote-ext placeholder '%%%c'.",
  63                                        str[rpos]);
  64                        }
  65                        escape = 0;
  66                } else
  67                        escape = (str[rpos] == '%');
  68                rpos++;
  69        }
  70        if (escape && !str[rpos])
  71                die("remote-ext command has incomplete placeholder");
  72        *next = str + rpos;
  73        if (**next == ' ')
  74                ++*next;        /* Skip over space */
  75
  76        /*
  77         * Do the actual placeholder substitution. The string will be short
  78         * enough not to overflow integers.
  79         */
  80        rpos = special ? 2 : 0;         /* Skip first 2 bytes in specials. */
  81        escape = 0;
  82        while (str[rpos] && (escape || str[rpos] != ' ')) {
  83                if (escape) {
  84                        switch (str[rpos]) {
  85                        case ' ':
  86                        case '%':
  87                                strbuf_addch(&ret, str[rpos]);
  88                                break;
  89                        case 's':
  90                                strbuf_addstr(&ret, service_noprefix);
  91                                break;
  92                        case 'S':
  93                                strbuf_addstr(&ret, service);
  94                                break;
  95                        }
  96                        escape = 0;
  97                } else
  98                        switch (str[rpos]) {
  99                        case '%':
 100                                escape = 1;
 101                                break;
 102                        default:
 103                                strbuf_addch(&ret, str[rpos]);
 104                                break;
 105                        }
 106                rpos++;
 107        }
 108        switch (special) {
 109        case 'G':
 110                git_req = strbuf_detach(&ret, NULL);
 111                return NULL;
 112        case 'V':
 113                git_req_vhost = strbuf_detach(&ret, NULL);
 114                return NULL;
 115        default:
 116                return strbuf_detach(&ret, NULL);
 117        }
 118}
 119
 120static void parse_argv(struct argv_array *out, const char *arg, const char *service)
 121{
 122        while (*arg) {
 123                char *expanded = strip_escapes(arg, service, &arg);
 124                if (expanded)
 125                        argv_array_push(out, expanded);
 126                free(expanded);
 127        }
 128}
 129
 130static void send_git_request(int stdin_fd, const char *serv, const char *repo,
 131        const char *vhost)
 132{
 133        if (!vhost)
 134                packet_write_fmt(stdin_fd, "%s %s%c", serv, repo, 0);
 135        else
 136                packet_write_fmt(stdin_fd, "%s %s%chost=%s%c", serv, repo, 0,
 137                             vhost, 0);
 138}
 139
 140static int run_child(const char *arg, const char *service)
 141{
 142        int r;
 143        struct child_process child = CHILD_PROCESS_INIT;
 144
 145        child.in = -1;
 146        child.out = -1;
 147        child.err = 0;
 148        parse_argv(&child.args, arg, service);
 149
 150        if (start_command(&child) < 0)
 151                die("Can't run specified command");
 152
 153        if (git_req)
 154                send_git_request(child.in, service, git_req, git_req_vhost);
 155
 156        r = bidirectional_transfer_loop(child.out, child.in);
 157        if (!r)
 158                r = finish_command(&child);
 159        else
 160                finish_command(&child);
 161        return r;
 162}
 163
 164#define MAXCOMMAND 4096
 165
 166static int command_loop(const char *child)
 167{
 168        char buffer[MAXCOMMAND];
 169
 170        while (1) {
 171                size_t i;
 172                if (!fgets(buffer, MAXCOMMAND - 1, stdin)) {
 173                        if (ferror(stdin))
 174                                die("Command input error");
 175                        exit(0);
 176                }
 177                /* Strip end of line characters. */
 178                i = strlen(buffer);
 179                while (i > 0 && isspace(buffer[i - 1]))
 180                        buffer[--i] = 0;
 181
 182                if (!strcmp(buffer, "capabilities")) {
 183                        printf("*connect\n\n");
 184                        fflush(stdout);
 185                } else if (!strncmp(buffer, "connect ", 8)) {
 186                        printf("\n");
 187                        fflush(stdout);
 188                        return run_child(child, buffer + 8);
 189                } else {
 190                        fprintf(stderr, "Bad command");
 191                        return 1;
 192                }
 193        }
 194}
 195
 196int cmd_remote_ext(int argc, const char **argv, const char *prefix)
 197{
 198        if (argc != 3)
 199                usage(usage_msg);
 200
 201        return command_loop(argv[2]);
 202}