X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=daemon.c;h=539f6e87af9824ea331326ade71e343698e235fe;hb=457f06d68e427bbf4f1a921877441a622a05e5c4;hp=f285a8c98ca9fbfc421b735f76f9d9f2248bd749;hpb=64a2228b02594d5ccb7aaca293816f571fd1ea84;p=git.git diff --git a/daemon.c b/daemon.c index f285a8c9..539f6e87 100644 --- a/daemon.c +++ b/daemon.c @@ -1,5 +1,3 @@ -#include "cache.h" -#include "pkt-line.h" #include #include #include @@ -9,18 +7,26 @@ #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] [directory...]"; +static const char daemon_usage[] = +"git-daemon [--verbose] [--syslog] [--inetd | --port=n] [--export-all]\n" +" [--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; +/* Timeout, and initial timeout */ +static unsigned int timeout = 0; +static unsigned int init_timeout = 0; static void logreport(int priority, const char *err, va_list params) { @@ -76,75 +82,124 @@ 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 = 1, ndot = 0; + int sl, ndot; - for (;;) { - if ( *p == '.' ) { - ndot++; - } else if ( *p == '/' || *p == '\0' ) { - if ( sl && ndot > 0 && ndot < 3 ) - return 0; /* . or .. in path */ + /* + * 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; - if ( *p == '\0' ) - break; /* End of string and all is good */ - } else { - sl = ndot = 0; + ndot = 0; } - p++; } +} - if ( ok_paths && *ok_paths ) { - int ok = 0; - int dirlen = strlen(dir); /* read_packet_line can return embedded \0 */ +static char *path_ok(char *dir) +{ + char *path; + + if (avoid_alias(dir)) { + logerror("'%s': aliased", dir); + return NULL; + } + + 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 upload(char *dir, int dirlen) +static int upload(char *dir) { - loginfo("Request for '%s'", dir); + /* Timeout as string */ + char timeout_buf[64]; + const char *path; - if (!path_ok(dir)) { - logerror("Forbidden directory: %s\n", dir); - return -1; - } + loginfo("Request for '%s'", dir); - if (chdir(dir) < 0) { - logerror("Cannot chdir('%s'): %s", dir, strerror(errno)); + if (!(path = path_ok(dir))) return -1; - } - - chdir(".git"); /* * Security on the cheap. * - * We want a readable HEAD, usable "objects" directory, and + * 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)) || - access("objects/00", X_OK) || - access("HEAD", R_OK)) { - logerror("Not a valid git-daemon-enabled repository: '%s'", dir); + + if (!export_all_trees && access("git-daemon-export-ok", F_OK)) { + logerror("'%s': repository not exported.", path); + errno = EACCES; return -1; } @@ -154,8 +209,10 @@ static int upload(char *dir, int dirlen) */ signal(SIGTERM, SIG_IGN); + 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", ".", NULL); + execlp("git-upload-pack", "git-upload-pack", "--strict", timeout_buf, ".", NULL); return -1; } @@ -164,13 +221,15 @@ static int execute(void) static char line[1000]; int len; + alarm(init_timeout ? init_timeout : timeout); len = packet_read_line(0, line, sizeof(line)); + alarm(0); if (len && line[len-1] == '\n') line[--len] = 0; - if (!strncmp("git-upload-pack /", line, 17)) - return upload(line + 16, len - 16); + if (!strncmp("git-upload-pack ", line, 16)) + return upload(line+16); logerror("Protocol error: '%s'", line); return -1; @@ -463,8 +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 @@ -482,11 +547,11 @@ static int service_loop(int socknum, int *socklist) } signal(SIGCHLD, child_handler); - + for (;;) { int i; - if (poll(pfd, socknum, 0) < 0) { + if (poll(pfd, socknum, -1) < 0) { if (errno != EINTR) { error("poll failed, resuming: %s", strerror(errno)); @@ -519,13 +584,13 @@ 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) { @@ -547,6 +612,7 @@ int main(int argc, char **argv) } if (!strcmp(arg, "--inetd")) { inetd_mode = 1; + log_syslog = 1; continue; } if (!strcmp(arg, "--verbose")) { @@ -555,13 +621,24 @@ 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")) { export_all_trees = 1; continue; } + 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]; break; @@ -573,10 +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); }