diff options
Diffstat (limited to 'builtin/remote-ext.c')
| -rw-r--r-- | builtin/remote-ext.c | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/builtin/remote-ext.c b/builtin/remote-ext.c new file mode 100644 index 0000000000..692c834d9d --- /dev/null +++ b/builtin/remote-ext.c @@ -0,0 +1,242 @@ +#include "builtin.h" +#include "transport.h" +#include "run-command.h" + +/* + * URL syntax: + * 'command [arg1 [arg2 [...]]]' Invoke command with given arguments. + * Special characters: + * '% ': Literal space in argument. + * '%%': Literal percent sign. + * '%S': Name of service (git-upload-pack/git-upload-archive/ + * git-receive-pack. + * '%s': Same as \s, but with possible git- prefix stripped. + * '%G': Only allowed as first 'character' of argument. Do not pass this + * Argument to command, instead send this as name of repository + * in in-line git://-style request (also activates sending this + * style of request). + * '%V': Only allowed as first 'character' of argument. Used in + * conjunction with '%G': Do not pass this argument to command, + * instead send this as vhost in git://-style request (note: does + * not activate sending git:// style request). + */ + +static char *git_req; +static char *git_req_vhost; + +static char *strip_escapes(const char *str, const char *service, + const char **next) +{ + size_t rpos = 0; + int escape = 0; + char special = 0; + size_t psoff = 0; + struct strbuf ret = STRBUF_INIT; + + /* Calculate prefix length for \s and lengths for \s and \S */ + if (!strncmp(service, "git-", 4)) + psoff = 4; + + /* Pass the service to command. */ + setenv("GIT_EXT_SERVICE", service, 1); + setenv("GIT_EXT_SERVICE_NOPREFIX", service + psoff, 1); + + /* Scan the length of argument. */ + while (str[rpos] && (escape || str[rpos] != ' ')) { + if (escape) { + switch (str[rpos]) { + case ' ': + case '%': + case 's': + case 'S': + break; + case 'G': + case 'V': + special = str[rpos]; + if (rpos == 1) + break; + /* Fall-through to error. */ + default: + die("Bad remote-ext placeholder '%%%c'.", + str[rpos]); + } + escape = 0; + } else + escape = (str[rpos] == '%'); + rpos++; + } + if (escape && !str[rpos]) + die("remote-ext command has incomplete placeholder"); + *next = str + rpos; + if (**next == ' ') + ++*next; /* Skip over space */ + + /* + * Do the actual placeholder substitution. The string will be short + * enough not to overflow integers. + */ + rpos = special ? 2 : 0; /* Skip first 2 bytes in specials. */ + escape = 0; + while (str[rpos] && (escape || str[rpos] != ' ')) { + if (escape) { + switch (str[rpos]) { + case ' ': + case '%': + strbuf_addch(&ret, str[rpos]); + break; + case 's': + strbuf_addstr(&ret, service + psoff); + break; + case 'S': + strbuf_addstr(&ret, service); + break; + } + escape = 0; + } else + switch (str[rpos]) { + case '%': + escape = 1; + break; + default: + strbuf_addch(&ret, str[rpos]); + break; + } + rpos++; + } + switch (special) { + case 'G': + git_req = strbuf_detach(&ret, NULL); + return NULL; + case 'V': + git_req_vhost = strbuf_detach(&ret, NULL); + return NULL; + default: + return strbuf_detach(&ret, NULL); + } +} + +/* Should be enough... */ +#define MAXARGUMENTS 256 + +static const char **parse_argv(const char *arg, const char *service) +{ + int arguments = 0; + int i; + const char **ret; + char *temparray[MAXARGUMENTS + 1]; + + while (*arg) { + char *expanded; + if (arguments == MAXARGUMENTS) + die("remote-ext command has too many arguments"); + expanded = strip_escapes(arg, service, &arg); + if (expanded) + temparray[arguments++] = expanded; + } + + ret = xmalloc((arguments + 1) * sizeof(char *)); + for (i = 0; i < arguments; i++) + ret[i] = temparray[i]; + ret[arguments] = NULL; + return ret; +} + +static void send_git_request(int stdin_fd, const char *serv, const char *repo, + const char *vhost) +{ + size_t bufferspace; + size_t wpos = 0; + char *buffer; + + /* + * Request needs 12 bytes extra if there is vhost (xxxx \0host=\0) and + * 6 bytes extra (xxxx \0) if there is no vhost. + */ + if (vhost) + bufferspace = strlen(serv) + strlen(repo) + strlen(vhost) + 12; + else + bufferspace = strlen(serv) + strlen(repo) + 6; + + if (bufferspace > 0xFFFF) + die("Request too large to send"); + buffer = xmalloc(bufferspace); + + /* Make the packet. */ + wpos = sprintf(buffer, "%04x%s %s%c", (unsigned)bufferspace, + serv, repo, 0); + + /* Add vhost if any. */ + if (vhost) + sprintf(buffer + wpos, "host=%s%c", vhost, 0); + + /* Send the request */ + if (write_in_full(stdin_fd, buffer, bufferspace) < 0) + die_errno("Failed to send request"); + + free(buffer); +} + +static int run_child(const char *arg, const char *service) +{ + int r; + struct child_process child; + + memset(&child, 0, sizeof(child)); + child.in = -1; + child.out = -1; + child.err = 0; + child.argv = parse_argv(arg, service); + + if (start_command(&child) < 0) + die("Can't run specified command"); + + if (git_req) + send_git_request(child.in, service, git_req, git_req_vhost); + + r = bidirectional_transfer_loop(child.out, child.in); + if (!r) + r = finish_command(&child); + else + finish_command(&child); + return r; +} + +#define MAXCOMMAND 4096 + +static int command_loop(const char *child) +{ + char buffer[MAXCOMMAND]; + + while (1) { + size_t i; + if (!fgets(buffer, MAXCOMMAND - 1, stdin)) { + if (ferror(stdin)) + die("Comammand input error"); + exit(0); + } + /* Strip end of line characters. */ + i = strlen(buffer); + while (i > 0 && isspace(buffer[i - 1])) + buffer[--i] = 0; + + if (!strcmp(buffer, "capabilities")) { + printf("*connect\n\n"); + fflush(stdout); + } else if (!strncmp(buffer, "connect ", 8)) { + printf("\n"); + fflush(stdout); + return run_child(child, buffer + 8); + } else { + fprintf(stderr, "Bad command"); + return 1; + } + } +} + +int cmd_remote_ext(int argc, const char **argv, const char *prefix) +{ + if (argc != 3) + die("Expected two arguments"); + + return command_loop(argv[2]); +} |