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-rw-r--r--daemon.c375
1 files changed, 217 insertions, 158 deletions
diff --git a/daemon.c b/daemon.c
index eba1255..f9eb296 100644
--- a/daemon.c
+++ b/daemon.c
@@ -39,13 +39,10 @@ static int strict_paths;
static int export_all_trees;
/* Take all paths relative to this one if non-NULL */
-static char *base_path;
-static char *interpolated_path;
+static const char *base_path;
+static const char *interpolated_path;
static int base_path_relaxed;
-/* 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.
@@ -56,10 +53,28 @@ static const char *user_path;
static unsigned int timeout;
static unsigned int init_timeout;
-static char *hostname;
-static char *canon_hostname;
-static char *ip_address;
-static char *tcp_port;
+struct hostinfo {
+ struct strbuf hostname;
+ struct strbuf canon_hostname;
+ struct strbuf ip_address;
+ struct strbuf tcp_port;
+ unsigned int hostname_lookup_done:1;
+ unsigned int saw_extended_args:1;
+};
+
+static void lookup_hostname(struct hostinfo *hi);
+
+static const char *get_canon_hostname(struct hostinfo *hi)
+{
+ lookup_hostname(hi);
+ return hi->canon_hostname.buf;
+}
+
+static const char *get_ip_address(struct hostinfo *hi)
+{
+ lookup_hostname(hi);
+ return hi->ip_address.buf;
+}
static void logreport(int priority, const char *err, va_list params)
{
@@ -106,12 +121,48 @@ static void NORETURN daemon_die(const char *err, va_list params)
exit(1);
}
-static const char *path_ok(char *directory)
+struct expand_path_context {
+ const char *directory;
+ struct hostinfo *hostinfo;
+};
+
+static size_t expand_path(struct strbuf *sb, const char *placeholder, void *ctx)
+{
+ struct expand_path_context *context = ctx;
+ struct hostinfo *hi = context->hostinfo;
+
+ switch (placeholder[0]) {
+ case 'H':
+ strbuf_addbuf(sb, &hi->hostname);
+ return 1;
+ case 'C':
+ if (placeholder[1] == 'H') {
+ strbuf_addstr(sb, get_canon_hostname(hi));
+ return 2;
+ }
+ break;
+ case 'I':
+ if (placeholder[1] == 'P') {
+ strbuf_addstr(sb, get_ip_address(hi));
+ return 2;
+ }
+ break;
+ case 'P':
+ strbuf_addbuf(sb, &hi->tcp_port);
+ return 1;
+ case 'D':
+ strbuf_addstr(sb, context->directory);
+ return 1;
+ }
+ return 0;
+}
+
+static const char *path_ok(const char *directory, struct hostinfo *hi)
{
static char rpath[PATH_MAX];
static char interp_path[PATH_MAX];
const char *path;
- char *dir;
+ const char *dir;
dir = directory;
@@ -131,7 +182,7 @@ static const char *path_ok(char *directory)
* "~alice/%s/foo".
*/
int namlen, restlen = strlen(dir);
- char *slash = strchr(dir, '/');
+ const char *slash = strchr(dir, '/');
if (!slash)
slash = dir + restlen;
namlen = slash - dir;
@@ -142,16 +193,13 @@ static const char *path_ok(char *directory)
dir = rpath;
}
}
- else if (interpolated_path && saw_extended_args) {
+ else if (interpolated_path && hi->saw_extended_args) {
struct strbuf expanded_path = STRBUF_INIT;
- struct strbuf_expand_dict_entry dict[6];
-
- dict[0].placeholder = "H"; dict[0].value = hostname;
- dict[1].placeholder = "CH"; dict[1].value = canon_hostname;
- dict[2].placeholder = "IP"; dict[2].value = ip_address;
- dict[3].placeholder = "P"; dict[3].value = tcp_port;
- dict[4].placeholder = "D"; dict[4].value = directory;
- dict[5].placeholder = NULL; dict[5].value = NULL;
+ struct expand_path_context context;
+
+ context.directory = directory;
+ context.hostinfo = hi;
+
if (*dir != '/') {
/* Allow only absolute */
logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
@@ -159,7 +207,7 @@ static const char *path_ok(char *directory)
}
strbuf_expand(&expanded_path, interpolated_path,
- strbuf_expand_dict_cb, &dict);
+ expand_path, &context);
strlcpy(interp_path, expanded_path.buf, PATH_MAX);
strbuf_release(&expanded_path);
loginfo("Interpolated dir '%s'", interp_path);
@@ -230,21 +278,6 @@ struct daemon_service {
int overridable;
};
-static struct daemon_service *service_looking_at;
-static int service_enabled;
-
-static int git_daemon_config(const char *var, const char *value, void *cb)
-{
- if (starts_with(var, "daemon.") &&
- !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 daemon_error(const char *dir, const char *msg)
{
if (!informative_errors)
@@ -253,29 +286,27 @@ static int daemon_error(const char *dir, const char *msg)
return -1;
}
-static char *access_hook;
+static const char *access_hook;
-static int run_access_hook(struct daemon_service *service, const char *dir, const char *path)
+static int run_access_hook(struct daemon_service *service, const char *dir,
+ const char *path, struct hostinfo *hi)
{
- struct child_process child;
+ struct child_process child = CHILD_PROCESS_INIT;
struct strbuf buf = STRBUF_INIT;
const char *argv[8];
const char **arg = argv;
char *eol;
int seen_errors = 0;
-#define STRARG(x) ((x) ? (x) : "")
*arg++ = access_hook;
*arg++ = service->name;
*arg++ = path;
- *arg++ = STRARG(hostname);
- *arg++ = STRARG(canon_hostname);
- *arg++ = STRARG(ip_address);
- *arg++ = STRARG(tcp_port);
+ *arg++ = hi->hostname.buf;
+ *arg++ = get_canon_hostname(hi);
+ *arg++ = get_ip_address(hi);
+ *arg++ = hi->tcp_port.buf;
*arg = NULL;
-#undef STRARG
- memset(&child, 0, sizeof(child));
child.use_shell = 1;
child.argv = argv;
child.no_stdin = 1;
@@ -318,10 +349,12 @@ error_return:
return -1;
}
-static int run_service(char *dir, struct daemon_service *service)
+static int run_service(const char *dir, struct daemon_service *service,
+ struct hostinfo *hi)
{
const char *path;
int enabled = service->enabled;
+ struct strbuf var = STRBUF_INIT;
loginfo("Request %s for '%s'", service->name, dir);
@@ -331,7 +364,7 @@ static int run_service(char *dir, struct daemon_service *service)
return daemon_error(dir, "service not enabled");
}
- if (!(path = path_ok(dir)))
+ if (!(path = path_ok(dir, hi)))
return daemon_error(dir, "no such repository");
/*
@@ -352,11 +385,9 @@ static int run_service(char *dir, struct daemon_service *service)
}
if (service->overridable) {
- service_looking_at = service;
- service_enabled = -1;
- git_config(git_daemon_config, NULL);
- if (0 <= service_enabled)
- enabled = service_enabled;
+ strbuf_addf(&var, "daemon.%s", service->config_name);
+ git_config_get_bool(var.buf, &enabled);
+ strbuf_release(&var);
}
if (!enabled) {
logerror("'%s': service not enabled for '%s'",
@@ -369,7 +400,7 @@ static int run_service(char *dir, struct daemon_service *service)
* Optionally, a hook can choose to deny access to the
* repository depending on the phase of the moon.
*/
- if (access_hook && run_access_hook(service, dir, path))
+ if (access_hook && run_access_hook(service, dir, path, hi))
return -1;
/*
@@ -404,9 +435,8 @@ static void copy_to_log(int fd)
static int run_service_command(const char **argv)
{
- struct child_process cld;
+ struct child_process cld = CHILD_PROCESS_INIT;
- memset(&cld, 0, sizeof(cld));
cld.argv = argv;
cld.git_cmd = 1;
cld.err = -1;
@@ -475,14 +505,6 @@ static void make_service_overridable(const char *name, int ena)
die("No such service %s", name);
}
-static char *xstrdup_tolower(const char *str)
-{
- char *p, *dup = xstrdup(str);
- for (p = dup; *p; p++)
- *p = tolower(*p);
- return dup;
-}
-
static void parse_host_and_port(char *hostport, char **host,
char **port)
{
@@ -511,16 +533,46 @@ static void parse_host_and_port(char *hostport, char **host,
}
/*
+ * Sanitize a string from the client so that it's OK to be inserted into a
+ * filesystem path. Specifically, we disallow slashes, runs of "..", and
+ * trailing and leading dots, which means that the client cannot escape
+ * our base path via ".." traversal.
+ */
+static void sanitize_client(struct strbuf *out, const char *in)
+{
+ for (; *in; in++) {
+ if (*in == '/')
+ continue;
+ if (*in == '.' && (!out->len || out->buf[out->len - 1] == '.'))
+ continue;
+ strbuf_addch(out, *in);
+ }
+
+ while (out->len && out->buf[out->len - 1] == '.')
+ strbuf_setlen(out, out->len - 1);
+}
+
+/*
+ * Like sanitize_client, but we also perform any canonicalization
+ * to make life easier on the admin.
+ */
+static void canonicalize_client(struct strbuf *out, const char *in)
+{
+ sanitize_client(out, in);
+ strbuf_tolower(out);
+}
+
+/*
* Read the host as supplied by the client connection.
*/
-static void parse_host_arg(char *extra_args, int buflen)
+static void parse_host_arg(struct hostinfo *hi, char *extra_args, int buflen)
{
char *val;
int vallen;
char *end = extra_args + buflen;
if (extra_args < end && *extra_args) {
- saw_extended_args = 1;
+ hi->saw_extended_args = 1;
if (strncasecmp("host=", extra_args, 5) == 0) {
val = extra_args + 5;
vallen = strlen(val) + 1;
@@ -529,12 +581,10 @@ static void parse_host_arg(char *extra_args, int buflen)
char *host;
char *port;
parse_host_and_port(val, &host, &port);
- if (port) {
- free(tcp_port);
- tcp_port = xstrdup(port);
- }
- free(hostname);
- hostname = xstrdup_tolower(host);
+ if (port)
+ sanitize_client(&hi->tcp_port, port);
+ canonicalize_client(&hi->hostname, host);
+ hi->hostname_lookup_done = 0;
}
/* On to the next one */
@@ -543,11 +593,14 @@ static void parse_host_arg(char *extra_args, int buflen)
if (extra_args < end && *extra_args)
die("Invalid request");
}
+}
- /*
- * Locate canonical hostname and its IP address.
- */
- if (hostname) {
+/*
+ * Locate canonical hostname and its IP address.
+ */
+static void lookup_hostname(struct hostinfo *hi)
+{
+ if (!hi->hostname_lookup_done && hi->hostname.len) {
#ifndef NO_IPV6
struct addrinfo hints;
struct addrinfo *ai;
@@ -557,18 +610,20 @@ static void parse_host_arg(char *extra_args, int buflen)
memset(&hints, 0, sizeof(hints));
hints.ai_flags = AI_CANONNAME;
- gai = getaddrinfo(hostname, NULL, &hints, &ai);
+ gai = getaddrinfo(hi->hostname.buf, NULL, &hints, &ai);
if (!gai) {
struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
inet_ntop(AF_INET, &sin_addr->sin_addr,
addrbuf, sizeof(addrbuf));
- free(ip_address);
- ip_address = xstrdup(addrbuf);
+ strbuf_addstr(&hi->ip_address, addrbuf);
- free(canon_hostname);
- canon_hostname = xstrdup(ai->ai_canonname ?
- ai->ai_canonname : ip_address);
+ if (ai->ai_canonname)
+ sanitize_client(&hi->canon_hostname,
+ ai->ai_canonname);
+ else
+ strbuf_addbuf(&hi->canon_hostname,
+ &hi->ip_address);
freeaddrinfo(ai);
}
@@ -578,31 +633,50 @@ static void parse_host_arg(char *extra_args, int buflen)
char **ap;
static char addrbuf[HOST_NAME_MAX + 1];
- hent = gethostbyname(hostname);
-
- 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);
+ hent = gethostbyname(hi->hostname.buf);
+ if (hent) {
+ 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));
+ inet_ntop(hent->h_addrtype, &sa.sin_addr,
+ addrbuf, sizeof(addrbuf));
- free(canon_hostname);
- canon_hostname = xstrdup(hent->h_name);
- free(ip_address);
- ip_address = xstrdup(addrbuf);
+ sanitize_client(&hi->canon_hostname, hent->h_name);
+ strbuf_addstr(&hi->ip_address, addrbuf);
+ }
#endif
+ hi->hostname_lookup_done = 1;
}
}
+static void hostinfo_init(struct hostinfo *hi)
+{
+ memset(hi, 0, sizeof(*hi));
+ strbuf_init(&hi->hostname, 0);
+ strbuf_init(&hi->canon_hostname, 0);
+ strbuf_init(&hi->ip_address, 0);
+ strbuf_init(&hi->tcp_port, 0);
+}
+
+static void hostinfo_clear(struct hostinfo *hi)
+{
+ strbuf_release(&hi->hostname);
+ strbuf_release(&hi->canon_hostname);
+ strbuf_release(&hi->ip_address);
+ strbuf_release(&hi->tcp_port);
+}
static int execute(void)
{
char *line = packet_buffer;
int pktlen, len, i;
char *addr = getenv("REMOTE_ADDR"), *port = getenv("REMOTE_PORT");
+ struct hostinfo hi;
+
+ hostinfo_init(&hi);
if (addr)
loginfo("Connection from %s:%s", addr, port);
@@ -621,29 +695,27 @@ static int execute(void)
pktlen--;
}
- free(hostname);
- free(canon_hostname);
- free(ip_address);
- free(tcp_port);
- hostname = canon_hostname = ip_address = tcp_port = NULL;
-
if (len != pktlen)
- parse_host_arg(line + len + 1, pktlen - len - 1);
+ parse_host_arg(&hi, line + len + 1, pktlen - len - 1);
for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
struct daemon_service *s = &(daemon_service[i]);
- int namelen = strlen(s->name);
- if (starts_with(line, "git-") &&
- !strncmp(s->name, line + 4, namelen) &&
- line[namelen + 4] == ' ') {
+ const char *arg;
+
+ if (skip_prefix(line, "git-", &arg) &&
+ skip_prefix(arg, s->name, &arg) &&
+ *arg++ == ' ') {
/*
* Note: The directory here is probably context sensitive,
* and might depend on the actual service being performed.
*/
- return run_service(line + namelen + 5, s);
+ int rc = run_service(arg, s, &hi);
+ hostinfo_clear(&hi);
+ return rc;
}
}
+ hostinfo_clear(&hi);
logerror("Protocol error: '%s'", line);
return -1;
}
@@ -738,7 +810,7 @@ static void check_dead_children(void)
static char **cld_argv;
static void handle(int incoming, struct sockaddr *addr, socklen_t addrlen)
{
- struct child_process cld = { NULL };
+ struct child_process cld = CHILD_PROCESS_INIT;
char addrbuf[300] = "REMOTE_ADDR=", portbuf[300];
char *env[] = { addrbuf, portbuf, NULL };
@@ -783,7 +855,6 @@ static void handle(int incoming, struct sockaddr *addr, socklen_t addrlen)
logerror("unable to fork");
else
add_child(&cld, addr, addrlen);
- close(incoming);
}
static void child_handler(int signo)
@@ -840,7 +911,6 @@ static const char *ip2str(int family, struct sockaddr *sin, socklen_t len)
static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
{
int socknum = 0;
- int maxfd = -1;
char pbuf[NI_MAXSERV];
struct addrinfo hints, *ai0, *ai;
int gai;
@@ -908,9 +978,6 @@ static int setup_named_sock(char *listen_addr, int listen_port, struct socketlis
ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
socklist->list[socklist->nr++] = sockfd;
socknum++;
-
- if (maxfd < sockfd)
- maxfd = sockfd;
}
freeaddrinfo(ai0);
@@ -949,7 +1016,7 @@ static int setup_named_sock(char *listen_addr, int listen_port, struct socketlis
}
if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
- logerror("Could not listen to %s: %s",
+ logerror("Could not bind to %s: %s",
ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
strerror(errno));
close(sockfd);
@@ -1099,15 +1166,6 @@ static struct credentials *prepare_credentials(const char *user_name,
}
#endif
-static void store_pid(const char *path)
-{
- FILE *f = fopen(path, "w");
- if (!f)
- die_errno("cannot open pid file '%s'", path);
- if (fprintf(f, "%"PRIuMAX"\n", (uintmax_t) getpid()) < 0 || fclose(f) != 0)
- die_errno("failed to write pid file '%s'", path);
-}
-
static int serve(struct string_list *listen_addr, int listen_port,
struct credentials *cred)
{
@@ -1141,16 +1199,17 @@ int main(int argc, char **argv)
for (i = 1; i < argc; i++) {
char *arg = argv[i];
+ const char *v;
- if (starts_with(arg, "--listen=")) {
- string_list_append(&listen_addr, xstrdup_tolower(arg + 9));
+ if (skip_prefix(arg, "--listen=", &v)) {
+ string_list_append(&listen_addr, xstrdup_tolower(v));
continue;
}
- if (starts_with(arg, "--port=")) {
+ if (skip_prefix(arg, "--port=", &v)) {
char *end;
unsigned long n;
- n = strtoul(arg+7, &end, 0);
- if (arg[7] && !*end) {
+ n = strtoul(v, &end, 0);
+ if (*v && !*end) {
listen_port = n;
continue;
}
@@ -1176,20 +1235,20 @@ int main(int argc, char **argv)
export_all_trees = 1;
continue;
}
- if (starts_with(arg, "--access-hook=")) {
- access_hook = arg + 14;
+ if (skip_prefix(arg, "--access-hook=", &v)) {
+ access_hook = v;
continue;
}
- if (starts_with(arg, "--timeout=")) {
- timeout = atoi(arg+10);
+ if (skip_prefix(arg, "--timeout=", &v)) {
+ timeout = atoi(v);
continue;
}
- if (starts_with(arg, "--init-timeout=")) {
- init_timeout = atoi(arg+15);
+ if (skip_prefix(arg, "--init-timeout=", &v)) {
+ init_timeout = atoi(v);
continue;
}
- if (starts_with(arg, "--max-connections=")) {
- max_connections = atoi(arg+18);
+ if (skip_prefix(arg, "--max-connections=", &v)) {
+ max_connections = atoi(v);
if (max_connections < 0)
max_connections = 0; /* unlimited */
continue;
@@ -1198,16 +1257,16 @@ int main(int argc, char **argv)
strict_paths = 1;
continue;
}
- if (starts_with(arg, "--base-path=")) {
- base_path = arg+12;
+ if (skip_prefix(arg, "--base-path=", &v)) {
+ base_path = v;
continue;
}
if (!strcmp(arg, "--base-path-relaxed")) {
base_path_relaxed = 1;
continue;
}
- if (starts_with(arg, "--interpolated-path=")) {
- interpolated_path = arg+20;
+ if (skip_prefix(arg, "--interpolated-path=", &v)) {
+ interpolated_path = v;
continue;
}
if (!strcmp(arg, "--reuseaddr")) {
@@ -1218,12 +1277,12 @@ int main(int argc, char **argv)
user_path = "";
continue;
}
- if (starts_with(arg, "--user-path=")) {
- user_path = arg + 12;
+ if (skip_prefix(arg, "--user-path=", &v)) {
+ user_path = v;
continue;
}
- if (starts_with(arg, "--pid-file=")) {
- pid_file = arg + 11;
+ if (skip_prefix(arg, "--pid-file=", &v)) {
+ pid_file = v;
continue;
}
if (!strcmp(arg, "--detach")) {
@@ -1231,28 +1290,28 @@ int main(int argc, char **argv)
log_syslog = 1;
continue;
}
- if (starts_with(arg, "--user=")) {
- user_name = arg + 7;
+ if (skip_prefix(arg, "--user=", &v)) {
+ user_name = v;
continue;
}
- if (starts_with(arg, "--group=")) {
- group_name = arg + 8;
+ if (skip_prefix(arg, "--group=", &v)) {
+ group_name = v;
continue;
}
- if (starts_with(arg, "--enable=")) {
- enable_service(arg + 9, 1);
+ if (skip_prefix(arg, "--enable=", &v)) {
+ enable_service(v, 1);
continue;
}
- if (starts_with(arg, "--disable=")) {
- enable_service(arg + 10, 0);
+ if (skip_prefix(arg, "--disable=", &v)) {
+ enable_service(v, 0);
continue;
}
- if (starts_with(arg, "--allow-override=")) {
- make_service_overridable(arg + 17, 1);
+ if (skip_prefix(arg, "--allow-override=", &v)) {
+ make_service_overridable(v, 1);
continue;
}
- if (starts_with(arg, "--forbid-override=")) {
- make_service_overridable(arg + 18, 0);
+ if (skip_prefix(arg, "--forbid-override=", &v)) {
+ make_service_overridable(v, 0);
continue;
}
if (!strcmp(arg, "--informative-errors")) {
@@ -1317,7 +1376,7 @@ int main(int argc, char **argv)
sanitize_stdfds();
if (pid_file)
- store_pid(pid_file);
+ write_file(pid_file, "%"PRIuMAX, (uintmax_t) getpid());
/* prepare argv for serving-processes */
cld_argv = xmalloc(sizeof (char *) * (argc + 2));
generated by cgit v0.10.2-6-g49f6 at 2024-04-25 17:03:14 (GMT)