X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=daemon.c;h=539f6e87af9824ea331326ade71e343698e235fe;hb=e99fcf96deab45ca81b22948328deb2d8586aa8d;hp=0c6182fb93fce6937ecb2634462f7f6b0a835662;hpb=4ae22d96fe9248dac4f26b1fc91154ba5e879799;p=git.git diff --git a/daemon.c b/daemon.c index 0c6182fb..539f6e87 100644 --- a/daemon.c +++ b/daemon.c @@ -1,5 +1,3 @@ -#include "cache.h" -#include "pkt-line.h" #include #include #include @@ -9,16 +7,19 @@ #include #include #include +#include "pkt-line.h" +#include "cache.h" static int log_syslog; static int verbose; static const char daemon_usage[] = "git-daemon [--verbose] [--syslog] [--inetd | --port=n] [--export-all]\n" -" [--timeout=n] [--init-timeout=n] [directory...]"; +" [--timeout=n] [--init-timeout=n] [--strict-paths] [directory...]"; /* List of acceptable pathname prefixes */ static char **ok_paths = NULL; +static int strict_paths = 0; /* If this is set, git-daemon-export-ok is not required */ static int export_all_trees = 0; @@ -81,69 +82,108 @@ static void loginfo(const char *err, ...) va_end(params); } -static int path_ok(const char *dir) +static int avoid_alias(char *p) { - const char *p = dir; - char **pp; int sl, ndot; - /* The pathname here should be an absolute path. */ - if ( *p++ != '/' ) - return 0; - - sl = 1; ndot = 0; - - for (;;) { - if ( *p == '.' ) { - ndot++; - } else if ( *p == '\0' ) { - /* Reject "." and ".." at the end of the path */ - if ( sl && ndot > 0 && ndot < 3 ) - return 0; - - /* Otherwise OK */ - break; - } else if ( *p == '/' ) { - /* Refuse "", "." or ".." */ - if ( sl && ndot < 3 ) + /* + * This resurrects the belts and suspenders paranoia check by HPA + * done in <435560F7.4080006@zytor.com> thread, now enter_repo() + * does not do getcwd() based path canonicalizations. + * + * sl becomes true immediately after seeing '/' and continues to + * be true as long as dots continue after that without intervening + * non-dot character. + */ + if (!p || (*p != '/' && *p != '~')) + return -1; + sl = 1; ndot = 0; + p++; + + while (1) { + char ch = *p++; + if (sl) { + if (ch == '.') + ndot++; + else if (ch == '/') { + if (ndot < 3) + /* reject //, /./ and /../ */ + return -1; + ndot = 0; + } + else if (ch == 0) { + if (0 < ndot && ndot < 3) + /* reject /.$ and /..$ */ + return -1; return 0; + } + else + sl = ndot = 0; + } + else if (ch == 0) + return 0; + else if (ch == '/') { sl = 1; ndot = 0; - } else { - sl = ndot = 0; } - p++; + } +} + +static char *path_ok(char *dir) +{ + char *path; + + if (avoid_alias(dir)) { + logerror("'%s': aliased", dir); + return NULL; } - if ( ok_paths && *ok_paths ) { - int ok = 0; - int dirlen = strlen(dir); + path = enter_repo(dir, strict_paths); + if (!path) { + logerror("'%s': unable to chdir or not a git archive", dir); + return NULL; + } + + if ( ok_paths && *ok_paths ) { + char **pp; + int pathlen = strlen(path); + + /* The validation is done on the paths after enter_repo + * appends optional {.git,.git/.git} and friends, but + * it does not use getcwd(). So if your /pub is + * a symlink to /mnt/pub, you can whitelist /pub and + * do not have to say /mnt/pub. + * Do not say /pub/. + */ for ( pp = ok_paths ; *pp ; pp++ ) { int len = strlen(*pp); - if ( len <= dirlen && - !strncmp(*pp, dir, len) && - (dir[len] == '/' || dir[len] == '\0') ) { - ok = 1; - break; - } + if (len <= pathlen && + !memcmp(*pp, path, len) && + (path[len] == '\0' || + (!strict_paths && path[len] == '/'))) + return path; } - - if ( !ok ) - return 0; /* Path not in whitelist */ + } + else { + /* be backwards compatible */ + if (!strict_paths) + return path; } - return 1; /* Path acceptable */ + logerror("'%s': not in whitelist", path); + return NULL; /* Fallthrough. Deny by default */ } -static int set_dir(const char *dir) +static int upload(char *dir) { - if (!path_ok(dir)) { - errno = EACCES; - return -1; - } + /* Timeout as string */ + char timeout_buf[64]; + const char *path; - if ( chdir(dir) ) + loginfo("Request for '%s'", dir); + + if (!(path = path_ok(dir))) return -1; /* @@ -152,45 +192,17 @@ static int set_dir(const char *dir) * We want a readable HEAD, usable "objects" directory, and * a "git-daemon-export-ok" flag that says that the other side * is ok with us doing this. + * + * path_ok() uses enter_repo() and does whitelist checking. + * We only need to make sure the repository is exported. */ + if (!export_all_trees && access("git-daemon-export-ok", F_OK)) { + logerror("'%s': repository not exported.", path); errno = EACCES; return -1; } - if (access("objects/", X_OK) || access("HEAD", R_OK)) { - errno = EINVAL; - return -1; - } - - /* If all this passed, we're OK */ - return 0; -} - -static int upload(char *dir) -{ - /* Try paths in this order */ - static const char *paths[] = { "%s", "%s/.git", "%s.git", "%s.git/.git", NULL }; - const char **pp; - /* Enough for the longest path above including final null */ - int buflen = strlen(dir)+10; - char *dirbuf = xmalloc(buflen); - /* Timeout as string */ - char timeout_buf[64]; - - loginfo("Request for '%s'", dir); - - for ( pp = paths ; *pp ; pp++ ) { - snprintf(dirbuf, buflen, *pp, dir); - if ( !set_dir(dirbuf) ) - break; - } - - if ( !*pp ) { - logerror("Cannot set directory '%s': %s", dir, strerror(errno)); - return -1; - } - /* * We'll ignore SIGTERM from now on, we have a * good client. @@ -216,7 +228,7 @@ static int execute(void) if (len && line[len-1] == '\n') line[--len] = 0; - if (!strncmp("git-upload-pack /", line, 17)) + if (!strncmp("git-upload-pack ", line, 16)) return upload(line+16); logerror("Protocol error: '%s'", line); @@ -510,8 +522,14 @@ static int socksetup(int port, int **socklist_p) return 0; } + if (listen(sockfd, 5) < 0) { + close(sockfd); + return 0; + } + *socklist_p = xmalloc(sizeof(int)); **socklist_p = sockfd; + return 1; } #endif @@ -594,6 +612,7 @@ int main(int argc, char **argv) } if (!strcmp(arg, "--inetd")) { inetd_mode = 1; + log_syslog = 1; continue; } if (!strcmp(arg, "--verbose")) { @@ -602,7 +621,6 @@ int main(int argc, char **argv) } if (!strcmp(arg, "--syslog")) { log_syslog = 1; - openlog("git-daemon", 0, LOG_DAEMON); continue; } if (!strcmp(arg, "--export-all")) { @@ -611,9 +629,15 @@ int main(int argc, char **argv) } if (!strncmp(arg, "--timeout=", 10)) { timeout = atoi(arg+10); + continue; } if (!strncmp(arg, "--init-timeout=", 15)) { init_timeout = atoi(arg+15); + continue; + } + if (!strcmp(arg, "--strict-paths")) { + strict_paths = 1; + continue; } if (!strcmp(arg, "--")) { ok_paths = &argv[i+1]; @@ -626,10 +650,21 @@ int main(int argc, char **argv) usage(daemon_usage); } + if (log_syslog) + openlog("git-daemon", 0, LOG_DAEMON); + + if (strict_paths && (!ok_paths || !*ok_paths)) { + if (!inetd_mode) + die("git-daemon: option --strict-paths requires a whitelist"); + + logerror("option --strict-paths requires a whitelist"); + exit (1); + } + if (inetd_mode) { fclose(stderr); //FIXME: workaround return execute(); - } else { - return serve(port); } + + return serve(port); }