X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=daemon.c;h=bb014fa9c2cb8c02a3952d0fc521358222662da1;hb=fc5be4fdaa063a667d17ae40e4ad130e2177b0f8;hp=2b56d7d225a703b6a206ad949a87765dff147760;hpb=54e31a205c63d8bc8cd3dcf6956f81d3b968ea48;p=git.git diff --git a/daemon.c b/daemon.c index 2b56d7d2..bb014fa9 100644 --- a/daemon.c +++ b/daemon.c @@ -1,5 +1,3 @@ -#include "cache.h" -#include "pkt-line.h" #include #include #include @@ -9,20 +7,28 @@ #include #include #include +#include "pkt-line.h" +#include "cache.h" +#include "exec_cmd.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]\n" +" [--base-path=path] [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; +/* Take all paths relative to this one if non-NULL */ +static char *base_path = NULL; + /* Timeout, and initial timeout */ static unsigned int timeout = 0; static unsigned int init_timeout = 0; @@ -81,113 +87,135 @@ 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++; } +} - if ( ok_paths && *ok_paths ) { - int ok = 0; - int dirlen = strlen(dir); +static char *path_ok(char *dir) +{ + char *path; - 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 (avoid_alias(dir)) { + logerror("'%s': aliased", dir); + return NULL; + } - if ( !ok ) - return 0; /* Path not in whitelist */ + if (base_path) { + static char rpath[PATH_MAX]; + if (*dir != '/') { + /* Forbid possible base-path evasion using ~paths. */ + logerror("'%s': Non-absolute path denied (base-path active)"); + return NULL; + } + snprintf(rpath, PATH_MAX, "%s%s", base_path, dir); + dir = rpath; } - return 1; /* Path acceptable */ -} + path = enter_repo(dir, strict_paths); -static int set_dir(const char *dir) -{ - if (!path_ok(dir)) { - errno = EACCES; - return -1; + if (!path) { + logerror("'%s': unable to chdir or not a git archive", dir); + return NULL; } - if ( chdir(dir) ) - return -1; - - /* - * Security on the cheap. - * - * 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. - */ - if (!export_all_trees && access("git-daemon-export-ok", F_OK)) { - errno = EACCES; - return -1; + 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 <= pathlen && + !memcmp(*pp, path, len) && + (path[len] == '\0' || + (!strict_paths && path[len] == '/'))) + return path; + } } - - if (access("objects/", X_OK) || access("HEAD", R_OK)) { - errno = EINVAL; - return -1; + else { + /* be backwards compatible */ + if (!strict_paths) + return path; } - /* If all this passed, we're OK */ - return 0; + logerror("'%s': not in whitelist", path); + return NULL; /* Fallthrough. Deny by default */ } 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]; + const char *path; loginfo("Request for '%s'", dir); - for ( pp = paths ; *pp ; pp++ ) { - snprintf(dirbuf, buflen, *pp, dir); - if ( !set_dir(dirbuf) ) - break; - } + if (!(path = path_ok(dir))) + return -1; - if ( !*pp ) { - logerror("Cannot set directory '%s': %s", dir, strerror(errno)); + /* + * Security on the cheap. + * + * 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; } @@ -200,7 +228,7 @@ static int upload(char *dir) snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout); /* git-upload-pack only ever reads stuff, so this is safe */ - execlp("git-upload-pack", "git-upload-pack", "--strict", timeout_buf, ".", NULL); + execl_git_cmd("upload-pack", "--strict", timeout_buf, ".", NULL); return -1; } @@ -216,7 +244,7 @@ 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 +538,14 @@ 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 @@ -529,7 +563,7 @@ static int service_loop(int socknum, int *socklist) } signal(SIGCHLD, child_handler); - + for (;;) { int i; @@ -566,13 +600,13 @@ static int service_loop(int socknum, int *socklist) static int serve(int port) { int socknum, *socklist; - + socknum = socksetup(port, &socklist); if (socknum == 0) die("unable to allocate any listen sockets on port %u", port); - + return service_loop(socknum, socklist); -} +} int main(int argc, char **argv) { @@ -594,6 +628,7 @@ int main(int argc, char **argv) } if (!strcmp(arg, "--inetd")) { inetd_mode = 1; + log_syslog = 1; continue; } if (!strcmp(arg, "--verbose")) { @@ -602,7 +637,6 @@ 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 +645,19 @@ 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 (!strncmp(arg, "--base-path=", 12)) { + base_path = arg+12; + continue; } if (!strcmp(arg, "--")) { ok_paths = &argv[i+1]; @@ -626,10 +670,21 @@ 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); }