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
   6/*
   7 * URL syntax:
   8 *      'command [arg1 [arg2 [...]]]'   Invoke command with given arguments.
   9 *      Special characters:
  10 *      '% ': Literal space in argument.
  11 *      '%%': Literal percent sign.
  12 *      '%S': Name of service (git-upload-pack/git-upload-archive/
  13 *              git-receive-pack.
  14 *      '%s': Same as \s, but with possible git- prefix stripped.
  15 *      '%G': Only allowed as first 'character' of argument. Do not pass this
  16 *              Argument to command, instead send this as name of repository
  17 *              in in-line git://-style request (also activates sending this
  18 *              style of request).
  19 *      '%V': Only allowed as first 'character' of argument. Used in
  20 *              conjunction with '%G': Do not pass this argument to command,
  21 *              instead send this as vhost in git://-style request (note: does
  22 *              not activate sending git:// style request).
  23 */
  24
  25static char *git_req;
  26static char *git_req_vhost;
  27
  28static char *strip_escapes(const char *str, const char *service,
  29        const char **next)
  30{
  31        size_t rpos = 0;
  32        int escape = 0;
  33        char special = 0;
  34        const char *service_noprefix = service;
  35        struct strbuf ret = STRBUF_INIT;
  36
  37        skip_prefix(service_noprefix, "git-", &service_noprefix);
  38
  39        /* Pass the service to command. */
  40        setenv("GIT_EXT_SERVICE", service, 1);
  41        setenv("GIT_EXT_SERVICE_NOPREFIX", service_noprefix, 1);
  42
  43        /* Scan the length of argument. */
  44        while (str[rpos] && (escape || str[rpos] != ' ')) {
  45                if (escape) {
  46                        switch (str[rpos]) {
  47                        case ' ':
  48                        case '%':
  49                        case 's':
  50                        case 'S':
  51                                break;
  52                        case 'G':
  53                        case 'V':
  54                                special = str[rpos];
  55                                if (rpos == 1)
  56                                        break;
  57                                /* Fall-through to error. */
  58                        default:
  59                                die("Bad remote-ext placeholder '%%%c'.",
  60                                        str[rpos]);
  61                        }
  62                        escape = 0;
  63                } else
  64                        escape = (str[rpos] == '%');
  65                rpos++;
  66        }
  67        if (escape && !str[rpos])
  68                die("remote-ext command has incomplete placeholder");
  69        *next = str + rpos;
  70        if (**next == ' ')
  71                ++*next;        /* Skip over space */
  72
  73        /*
  74         * Do the actual placeholder substitution. The string will be short
  75         * enough not to overflow integers.
  76         */
  77        rpos = special ? 2 : 0;         /* Skip first 2 bytes in specials. */
  78        escape = 0;
  79        while (str[rpos] && (escape || str[rpos] != ' ')) {
  80                if (escape) {
  81                        switch (str[rpos]) {
  82                        case ' ':
  83                        case '%':
  84                                strbuf_addch(&ret, str[rpos]);
  85                                break;
  86                        case 's':
  87                                strbuf_addstr(&ret, service_noprefix);
  88                                break;
  89                        case 'S':
  90                                strbuf_addstr(&ret, service);
  91                                break;
  92                        }
  93                        escape = 0;
  94                } else
  95                        switch (str[rpos]) {
  96                        case '%':
  97                                escape = 1;
  98                                break;
  99                        default:
 100                                strbuf_addch(&ret, str[rpos]);
 101                                break;
 102                        }
 103                rpos++;
 104        }
 105        switch (special) {
 106        case 'G':
 107                git_req = strbuf_detach(&ret, NULL);
 108                return NULL;
 109        case 'V':
 110                git_req_vhost = strbuf_detach(&ret, NULL);
 111                return NULL;
 112        default:
 113                return strbuf_detach(&ret, NULL);
 114        }
 115}
 116
 117/* Should be enough... */
 118#define MAXARGUMENTS 256
 119
 120static const char **parse_argv(const char *arg, const char *service)
 121{
 122        int arguments = 0;
 123        int i;
 124        const char **ret;
 125        char *temparray[MAXARGUMENTS + 1];
 126
 127        while (*arg) {
 128                char *expanded;
 129                if (arguments == MAXARGUMENTS)
 130                        die("remote-ext command has too many arguments");
 131                expanded = strip_escapes(arg, service, &arg);
 132                if (expanded)
 133                        temparray[arguments++] = expanded;
 134        }
 135
 136        ret = xmalloc((arguments + 1) * sizeof(char *));
 137        for (i = 0; i < arguments; i++)
 138                ret[i] = temparray[i];
 139        ret[arguments] = NULL;
 140        return ret;
 141}
 142
 143static void send_git_request(int stdin_fd, const char *serv, const char *repo,
 144        const char *vhost)
 145{
 146        if (!vhost)
 147                packet_write(stdin_fd, "%s %s%c", serv, repo, 0);
 148        else
 149                packet_write(stdin_fd, "%s %s%chost=%s%c", serv, repo, 0,
 150                             vhost, 0);
 151}
 152
 153static int run_child(const char *arg, const char *service)
 154{
 155        int r;
 156        struct child_process child = CHILD_PROCESS_INIT;
 157
 158        child.in = -1;
 159        child.out = -1;
 160        child.err = 0;
 161        child.argv = parse_argv(arg, service);
 162
 163        if (start_command(&child) < 0)
 164                die("Can't run specified command");
 165
 166        if (git_req)
 167                send_git_request(child.in, service, git_req, git_req_vhost);
 168
 169        r = bidirectional_transfer_loop(child.out, child.in);
 170        if (!r)
 171                r = finish_command(&child);
 172        else
 173                finish_command(&child);
 174        return r;
 175}
 176
 177#define MAXCOMMAND 4096
 178
 179static int command_loop(const char *child)
 180{
 181        char buffer[MAXCOMMAND];
 182
 183        while (1) {
 184                size_t i;
 185                if (!fgets(buffer, MAXCOMMAND - 1, stdin)) {
 186                        if (ferror(stdin))
 187                                die("Comammand input error");
 188                        exit(0);
 189                }
 190                /* Strip end of line characters. */
 191                i = strlen(buffer);
 192                while (i > 0 && isspace(buffer[i - 1]))
 193                        buffer[--i] = 0;
 194
 195                if (!strcmp(buffer, "capabilities")) {
 196                        printf("*connect\n\n");
 197                        fflush(stdout);
 198                } else if (!strncmp(buffer, "connect ", 8)) {
 199                        printf("\n");
 200                        fflush(stdout);
 201                        return run_child(child, buffer + 8);
 202                } else {
 203                        fprintf(stderr, "Bad command");
 204                        return 1;
 205                }
 206        }
 207}
 208
 209int cmd_remote_ext(int argc, const char **argv, const char *prefix)
 210{
 211        if (argc != 3)
 212                die("Expected two arguments");
 213
 214        return command_loop(argv[2]);
 215}