diff options
Diffstat (limited to 'daemon.c')
| -rw-r--r-- | daemon.c | 431 |
1 files changed, 383 insertions, 48 deletions
@@ -7,39 +7,77 @@ #include <netinet/in.h> #include <arpa/inet.h> #include <syslog.h> +#include <pwd.h> +#include <grp.h> +#include <limits.h> #include "pkt-line.h" #include "cache.h" #include "exec_cmd.h" +#include "interpolate.h" + +#ifndef HOST_NAME_MAX +#define HOST_NAME_MAX 256 +#endif static int log_syslog; static int verbose; static int reuseaddr; static const char daemon_usage[] = -"git-daemon [--verbose] [--syslog] [--inetd | --port=n] [--export-all]\n" +"git-daemon [--verbose] [--syslog] [--export-all]\n" " [--timeout=n] [--init-timeout=n] [--strict-paths]\n" " [--base-path=path] [--user-path | --user-path=path]\n" -" [--reuseaddr] [--detach] [--pid-file=file] [directory...]"; +" [--interpolated-path=path]\n" +" [--reuseaddr] [--detach] [--pid-file=file]\n" +" [--[enable|disable|allow-override|forbid-override]=service]\n" +" [--inetd | [--listen=host_or_ipaddr] [--port=n]\n" +" [--user=user [--group=group]]\n" +" [directory...]"; /* List of acceptable pathname prefixes */ -static char **ok_paths = NULL; -static int strict_paths = 0; +static char **ok_paths; +static int strict_paths; /* If this is set, git-daemon-export-ok is not required */ -static int export_all_trees = 0; +static int export_all_trees; /* Take all paths relative to this one if non-NULL */ -static char *base_path = NULL; +static char *base_path; +static char *interpolated_path; + +/* Flag indicating client sent extra args. */ +static int saw_extended_args; /* If defined, ~user notation is allowed and the string is inserted * after ~user/. E.g. a request to git://host/~alice/frotz would * go to /home/alice/pub_git/frotz with --user-path=pub_git. */ -static const char *user_path = NULL; +static const char *user_path; /* Timeout, and initial timeout */ -static unsigned int timeout = 0; -static unsigned int init_timeout = 0; +static unsigned int timeout; +static unsigned int init_timeout; + +/* + * Static table for now. Ugh. + * Feel free to make dynamic as needed. + */ +#define INTERP_SLOT_HOST (0) +#define INTERP_SLOT_CANON_HOST (1) +#define INTERP_SLOT_IP (2) +#define INTERP_SLOT_PORT (3) +#define INTERP_SLOT_DIR (4) +#define INTERP_SLOT_PERCENT (5) + +static struct interp interp_table[] = { + { "%H", 0}, + { "%CH", 0}, + { "%IP", 0}, + { "%P", 0}, + { "%D", 0}, + { "%%", 0}, +}; + static void logreport(int priority, const char *err, va_list params) { @@ -148,10 +186,14 @@ static int avoid_alias(char *p) } } -static char *path_ok(char *dir) +static char *path_ok(struct interp *itable) { static char rpath[PATH_MAX]; + static char interp_path[PATH_MAX]; char *path; + char *dir; + + dir = itable[INTERP_SLOT_DIR].value; if (avoid_alias(dir)) { logerror("'%s': aliased", dir); @@ -180,16 +222,27 @@ static char *path_ok(char *dir) dir = rpath; } } + else if (interpolated_path && saw_extended_args) { + if (*dir != '/') { + /* Allow only absolute */ + logerror("'%s': Non-absolute path denied (interpolated-path active)", dir); + return NULL; + } + + interpolate(interp_path, PATH_MAX, interpolated_path, + interp_table, ARRAY_SIZE(interp_table)); + loginfo("Interpolated dir '%s'", interp_path); + + dir = interp_path; + } else if (base_path) { if (*dir != '/') { /* Allow only absolute */ logerror("'%s': Non-absolute path denied (base-path active)", dir); return NULL; } - else { - snprintf(rpath, PATH_MAX, "%s%s", base_path, dir); - dir = rpath; - } + snprintf(rpath, PATH_MAX, "%s%s", base_path, dir); + dir = rpath; } path = enter_repo(dir, strict_paths); @@ -229,15 +282,46 @@ static char *path_ok(char *dir) return NULL; /* Fallthrough. Deny by default */ } -static int upload(char *dir) +typedef int (*daemon_service_fn)(void); +struct daemon_service { + const char *name; + const char *config_name; + daemon_service_fn fn; + int enabled; + int overridable; +}; + +static struct daemon_service *service_looking_at; +static int service_enabled; + +static int git_daemon_config(const char *var, const char *value) +{ + if (!strncmp(var, "daemon.", 7) && + !strcmp(var + 7, service_looking_at->config_name)) { + service_enabled = git_config_bool(var, value); + return 0; + } + + /* we are not interested in parsing any other configuration here */ + return 0; +} + +static int run_service(struct interp *itable, struct daemon_service *service) { - /* Timeout as string */ - char timeout_buf[64]; const char *path; + int enabled = service->enabled; + + loginfo("Request %s for '%s'", + service->name, + itable[INTERP_SLOT_DIR].value); - loginfo("Request for '%s'", dir); + if (!enabled && !service->overridable) { + logerror("'%s': service not enabled.", service->name); + errno = EACCES; + return -1; + } - if (!(path = path_ok(dir))) + if (!(path = path_ok(itable))) return -1; /* @@ -257,12 +341,34 @@ static int upload(char *dir) return -1; } + if (service->overridable) { + service_looking_at = service; + service_enabled = -1; + git_config(git_daemon_config); + if (0 <= service_enabled) + enabled = service_enabled; + } + if (!enabled) { + logerror("'%s': service not enabled for '%s'", + service->name, path); + errno = EACCES; + return -1; + } + /* * We'll ignore SIGTERM from now on, we have a * good client. */ signal(SIGTERM, SIG_IGN); + return service->fn(); +} + +static int upload_pack(void) +{ + /* Timeout as string */ + char timeout_buf[64]; + snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout); /* git-upload-pack only ever reads stuff, so this is safe */ @@ -270,10 +376,141 @@ static int upload(char *dir) return -1; } +static int upload_archive(void) +{ + execl_git_cmd("upload-archive", ".", NULL); + return -1; +} + +static struct daemon_service daemon_service[] = { + { "upload-archive", "uploadarch", upload_archive, 0, 1 }, + { "upload-pack", "uploadpack", upload_pack, 1, 1 }, +}; + +static void enable_service(const char *name, int ena) { + int i; + for (i = 0; i < ARRAY_SIZE(daemon_service); i++) { + if (!strcmp(daemon_service[i].name, name)) { + daemon_service[i].enabled = ena; + return; + } + } + die("No such service %s", name); +} + +static void make_service_overridable(const char *name, int ena) { + int i; + for (i = 0; i < ARRAY_SIZE(daemon_service); i++) { + if (!strcmp(daemon_service[i].name, name)) { + daemon_service[i].overridable = ena; + return; + } + } + die("No such service %s", name); +} + +/* + * Separate the "extra args" information as supplied by the client connection. + * Any resulting data is squirrelled away in the given interpolation table. + */ +static void parse_extra_args(struct interp *table, char *extra_args, int buflen) +{ + char *val; + int vallen; + char *end = extra_args + buflen; + + while (extra_args < end && *extra_args) { + saw_extended_args = 1; + if (strncasecmp("host=", extra_args, 5) == 0) { + val = extra_args + 5; + vallen = strlen(val) + 1; + if (*val) { + /* Split <host>:<port> at colon. */ + char *host = val; + char *port = strrchr(host, ':'); + if (port) { + *port = 0; + port++; + interp_set_entry(table, INTERP_SLOT_PORT, port); + } + interp_set_entry(table, INTERP_SLOT_HOST, host); + } + + /* On to the next one */ + extra_args = val + vallen; + } + } +} + +void fill_in_extra_table_entries(struct interp *itable) +{ + char *hp; + + /* + * Replace literal host with lowercase-ized hostname. + */ + hp = interp_table[INTERP_SLOT_HOST].value; + for ( ; *hp; hp++) + *hp = tolower(*hp); + + /* + * Locate canonical hostname and its IP address. + */ +#ifndef NO_IPV6 + { + struct addrinfo hints; + struct addrinfo *ai, *ai0; + int gai; + static char addrbuf[HOST_NAME_MAX + 1]; + + memset(&hints, 0, sizeof(hints)); + hints.ai_flags = AI_CANONNAME; + + gai = getaddrinfo(interp_table[INTERP_SLOT_HOST].value, 0, &hints, &ai0); + if (!gai) { + for (ai = ai0; ai; ai = ai->ai_next) { + struct sockaddr_in *sin_addr = (void *)ai->ai_addr; + + inet_ntop(AF_INET, &sin_addr->sin_addr, + addrbuf, sizeof(addrbuf)); + interp_set_entry(interp_table, + INTERP_SLOT_CANON_HOST, ai->ai_canonname); + interp_set_entry(interp_table, + INTERP_SLOT_IP, addrbuf); + break; + } + freeaddrinfo(ai0); + } + } +#else + { + struct hostent *hent; + struct sockaddr_in sa; + char **ap; + static char addrbuf[HOST_NAME_MAX + 1]; + + hent = gethostbyname(interp_table[INTERP_SLOT_HOST].value); + + ap = hent->h_addr_list; + memset(&sa, 0, sizeof sa); + sa.sin_family = hent->h_addrtype; + sa.sin_port = htons(0); + memcpy(&sa.sin_addr, *ap, hent->h_length); + + inet_ntop(hent->h_addrtype, &sa.sin_addr, + addrbuf, sizeof(addrbuf)); + + interp_set_entry(interp_table, INTERP_SLOT_CANON_HOST, hent->h_name); + interp_set_entry(interp_table, INTERP_SLOT_IP, addrbuf); + } +#endif +} + + static int execute(struct sockaddr *addr) { static char line[1000]; - int pktlen, len; + int pktlen, len, i; if (addr) { char addrbuf[256] = ""; @@ -310,8 +547,32 @@ static int execute(struct sockaddr *addr) if (len && line[len-1] == '\n') line[--len] = 0; - if (!strncmp("git-upload-pack ", line, 16)) - return upload(line+16); + /* + * Initialize the path interpolation table for this connection. + */ + interp_clear_table(interp_table, ARRAY_SIZE(interp_table)); + interp_set_entry(interp_table, INTERP_SLOT_PERCENT, "%"); + + if (len != pktlen) { + parse_extra_args(interp_table, line + len + 1, pktlen - len - 1); + fill_in_extra_table_entries(interp_table); + } + + for (i = 0; i < ARRAY_SIZE(daemon_service); i++) { + struct daemon_service *s = &(daemon_service[i]); + int namelen = strlen(s->name); + if (!strncmp("git-", line, 4) && + !strncmp(s->name, line + 4, namelen) && + line[namelen + 4] == ' ') { + /* + * Note: The directory here is probably context sensitive, + * and might depend on the actual service being performed. + */ + interp_set_entry(interp_table, + INTERP_SLOT_DIR, line + namelen + 5); + return run_service(interp_table, s); + } + } logerror("Protocol error: '%s'", line); return -1; @@ -333,12 +594,12 @@ static int execute(struct sockaddr *addr) static int max_connections = 25; /* These are updated by the signal handler */ -static volatile unsigned int children_reaped = 0; +static volatile unsigned int children_reaped; static pid_t dead_child[MAX_CHILDREN]; /* These are updated by the main loop */ -static unsigned int children_spawned = 0; -static unsigned int children_deleted = 0; +static unsigned int children_spawned; +static unsigned int children_deleted; static struct child { pid_t pid; @@ -504,29 +765,27 @@ static int set_reuse_addr(int sockfd) #ifndef NO_IPV6 -static int socksetup(int port, int **socklist_p) +static int socksetup(char *listen_addr, int listen_port, int **socklist_p) { int socknum = 0, *socklist = NULL; int maxfd = -1; char pbuf[NI_MAXSERV]; - struct addrinfo hints, *ai0, *ai; int gai; - sprintf(pbuf, "%d", port); + sprintf(pbuf, "%d", listen_port); memset(&hints, 0, sizeof(hints)); hints.ai_family = AF_UNSPEC; hints.ai_socktype = SOCK_STREAM; hints.ai_protocol = IPPROTO_TCP; hints.ai_flags = AI_PASSIVE; - gai = getaddrinfo(NULL, pbuf, &hints, &ai0); + gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0); if (gai) die("getaddrinfo() failed: %s\n", gai_strerror(gai)); for (ai = ai0; ai; ai = ai->ai_next) { int sockfd; - int *newlist; sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); if (sockfd < 0) @@ -560,11 +819,7 @@ static int socksetup(int port, int **socklist_p) continue; /* not fatal */ } - newlist = realloc(socklist, sizeof(int) * (socknum + 1)); - if (!newlist) - die("memory allocation failed: %s", strerror(errno)); - - socklist = newlist; + socklist = xrealloc(socklist, sizeof(int) * (socknum + 1)); socklist[socknum++] = sockfd; if (maxfd < sockfd) @@ -579,20 +834,27 @@ static int socksetup(int port, int **socklist_p) #else /* NO_IPV6 */ -static int socksetup(int port, int **socklist_p) +static int socksetup(char *listen_addr, int listen_port, int **socklist_p) { struct sockaddr_in sin; int sockfd; + memset(&sin, 0, sizeof sin); + sin.sin_family = AF_INET; + sin.sin_port = htons(listen_port); + + if (listen_addr) { + /* Well, host better be an IP address here. */ + if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0) + return 0; + } else { + sin.sin_addr.s_addr = htonl(INADDR_ANY); + } + sockfd = socket(AF_INET, SOCK_STREAM, 0); if (sockfd < 0) return 0; - memset(&sin, 0, sizeof sin); - sin.sin_family = AF_INET; - sin.sin_addr.s_addr = htonl(INADDR_ANY); - sin.sin_port = htons(port); - if (set_reuse_addr(sockfd)) { close(sockfd); return 0; @@ -701,23 +963,33 @@ static void store_pid(const char *path) fclose(f); } -static int serve(int port) +static int serve(char *listen_addr, int listen_port, struct passwd *pass, gid_t gid) { int socknum, *socklist; - socknum = socksetup(port, &socklist); + socknum = socksetup(listen_addr, listen_port, &socklist); if (socknum == 0) - die("unable to allocate any listen sockets on port %u", port); + die("unable to allocate any listen sockets on host %s port %u", + listen_addr, listen_port); + + if (pass && gid && + (initgroups(pass->pw_name, gid) || setgid (gid) || + setuid(pass->pw_uid))) + die("cannot drop privileges"); return service_loop(socknum, socklist); } int main(int argc, char **argv) { - int port = DEFAULT_GIT_PORT; + int listen_port = 0; + char *listen_addr = NULL; int inetd_mode = 0; - const char *pid_file = NULL; + const char *pid_file = NULL, *user_name = NULL, *group_name = NULL; int detach = 0; + struct passwd *pass = NULL; + struct group *group; + gid_t gid = 0; int i; /* Without this we cannot rely on waitpid() to tell @@ -728,12 +1000,20 @@ int main(int argc, char **argv) for (i = 1; i < argc; i++) { char *arg = argv[i]; + if (!strncmp(arg, "--listen=", 9)) { + char *p = arg + 9; + char *ph = listen_addr = xmalloc(strlen(arg + 9) + 1); + while (*p) + *ph++ = tolower(*p++); + *ph = 0; + continue; + } if (!strncmp(arg, "--port=", 7)) { char *end; unsigned long n; n = strtoul(arg+7, &end, 0); if (arg[7] && !*end) { - port = n; + listen_port = n; continue; } } @@ -770,6 +1050,10 @@ int main(int argc, char **argv) base_path = arg+12; continue; } + if (!strncmp(arg, "--interpolated-path=", 20)) { + interpolated_path = arg+20; + continue; + } if (!strcmp(arg, "--reuseaddr")) { reuseaddr = 1; continue; @@ -791,6 +1075,30 @@ int main(int argc, char **argv) log_syslog = 1; continue; } + if (!strncmp(arg, "--user=", 7)) { + user_name = arg + 7; + continue; + } + if (!strncmp(arg, "--group=", 8)) { + group_name = arg + 8; + continue; + } + if (!strncmp(arg, "--enable=", 9)) { + enable_service(arg + 9, 1); + continue; + } + if (!strncmp(arg, "--disable=", 10)) { + enable_service(arg + 10, 0); + continue; + } + if (!strncmp(arg, "--allow-override=", 17)) { + make_service_overridable(arg + 17, 1); + continue; + } + if (!strncmp(arg, "--forbid-override=", 18)) { + make_service_overridable(arg + 18, 0); + continue; + } if (!strcmp(arg, "--")) { ok_paths = &argv[i+1]; break; @@ -802,6 +1110,33 @@ int main(int argc, char **argv) usage(daemon_usage); } + if (inetd_mode && (group_name || user_name)) + die("--user and --group are incompatible with --inetd"); + + if (inetd_mode && (listen_port || listen_addr)) + die("--listen= and --port= are incompatible with --inetd"); + else if (listen_port == 0) + listen_port = DEFAULT_GIT_PORT; + + if (group_name && !user_name) + die("--group supplied without --user"); + + if (user_name) { + pass = getpwnam(user_name); + if (!pass) + die("user not found - %s", user_name); + + if (!group_name) + gid = pass->pw_gid; + else { + group = getgrnam(group_name); + if (!group) + die("group not found - %s", group_name); + + gid = group->gr_gid; + } + } + if (log_syslog) { openlog("git-daemon", 0, LOG_DAEMON); set_die_routine(daemon_die); @@ -831,5 +1166,5 @@ int main(int argc, char **argv) if (pid_file) store_pid(pid_file); - return serve(port); + return serve(listen_addr, listen_port, pass, gid); } |