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-rw-r--r--daemon.c225
1 files changed, 156 insertions, 69 deletions
diff --git a/daemon.c b/daemon.c
index 54a03bd527..f9eb296888 100644
--- a/daemon.c
+++ b/daemon.c
@@ -43,9 +43,6 @@ 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)
{
@@ -106,7 +121,43 @@ static void NORETURN daemon_die(const char *err, va_list params)
exit(1);
}
-static const char *path_ok(const 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];
@@ -142,16 +193,13 @@ static const char *path_ok(const 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(const 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);
@@ -240,7 +288,8 @@ static int daemon_error(const char *dir, const char *msg)
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 = CHILD_PROCESS_INIT;
struct strbuf buf = STRBUF_INIT;
@@ -249,16 +298,14 @@ static int run_access_hook(struct daemon_service *service, const char *dir, cons
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
child.use_shell = 1;
child.argv = argv;
@@ -302,7 +349,8 @@ error_return:
return -1;
}
-static int run_service(const 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;
@@ -316,7 +364,7 @@ static int run_service(const 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");
/*
@@ -352,7 +400,7 @@ static int run_service(const 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;
/*
@@ -485,16 +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;
@@ -503,12 +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 */
@@ -517,11 +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;
@@ -531,18 +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);
}
@@ -552,7 +633,7 @@ static void parse_host_arg(char *extra_args, int buflen)
char **ap;
static char addrbuf[HOST_NAME_MAX + 1];
- hent = gethostbyname(hostname);
+ hent = gethostbyname(hi->hostname.buf);
if (hent) {
ap = hent->h_addr_list;
memset(&sa, 0, sizeof sa);
@@ -563,21 +644,39 @@ static void parse_host_arg(char *extra_args, int buflen)
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);
@@ -596,14 +695,8 @@ 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]);
@@ -616,10 +709,13 @@ static int execute(void)
* Note: The directory here is probably context sensitive,
* and might depend on the actual service being performed.
*/
- return run_service(arg, s);
+ int rc = run_service(arg, s, &hi);
+ hostinfo_clear(&hi);
+ return rc;
}
}
+ hostinfo_clear(&hi);
logerror("Protocol error: '%s'", line);
return -1;
}
@@ -1070,15 +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)
{
@@ -1289,7 +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 v1.2.3 (git 2.25.1) at 2024-12-19 20:42:47 +0000