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daemon.c
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daemon.c
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#include "cache.h"
#include "pkt-line.h"
#include "exec_cmd.h"
#include "interpolate.h"
#include <syslog.h>
#ifndef HOST_NAME_MAX
#define HOST_NAME_MAX 256
#endif
#ifndef NI_MAXSERV
#define NI_MAXSERV 32
#endif
static int log_syslog;
static int verbose;
static int reuseaddr;
static const char daemon_usage[] =
"git-daemon [--verbose] [--syslog] [--export-all]\n"
" [--timeout=n] [--init-timeout=n] [--strict-paths]\n"
" [--base-path=path] [--base-path-relaxed]\n"
" [--user-path | --user-path=path]\n"
" [--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;
static int strict_paths;
/* If this is set, git-daemon-export-ok is not required */
static int export_all_trees;
/* Take all paths relative to this one if non-NULL */
static char *base_path;
static 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.
*/
static const char *user_path;
/* Timeout, and initial timeout */
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)
{
/* We should do a single write so that it is atomic and output
* of several processes do not get intermingled. */
char buf[1024];
int buflen;
int maxlen, msglen;
/* sizeof(buf) should be big enough for "[pid] \n" */
buflen = snprintf(buf, sizeof(buf), "[%ld] ", (long) getpid());
maxlen = sizeof(buf) - buflen - 1; /* -1 for our own LF */
msglen = vsnprintf(buf + buflen, maxlen, err, params);
if (log_syslog) {
syslog(priority, "%s", buf);
return;
}
/* maxlen counted our own LF but also counts space given to
* vsnprintf for the terminating NUL. We want to make sure that
* we have space for our own LF and NUL after the "meat" of the
* message, so truncate it at maxlen - 1.
*/
if (msglen > maxlen - 1)
msglen = maxlen - 1;
else if (msglen < 0)
msglen = 0; /* Protect against weird return values. */
buflen += msglen;
buf[buflen++] = '\n';
buf[buflen] = '\0';
write_in_full(2, buf, buflen);
}
static void logerror(const char *err, ...)
{
va_list params;
va_start(params, err);
logreport(LOG_ERR, err, params);
va_end(params);
}
static void loginfo(const char *err, ...)
{
va_list params;
if (!verbose)
return;
va_start(params, err);
logreport(LOG_INFO, err, params);
va_end(params);
}
static void NORETURN daemon_die(const char *err, va_list params)
{
logreport(LOG_ERR, err, params);
exit(1);
}
static int avoid_alias(char *p)
{
int sl, ndot;
/*
* 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;
}
}
}
static char *path_ok(struct interp *itable)
{
static char rpath[PATH_MAX];
static char interp_path[PATH_MAX];
int retried_path = 0;
char *path;
char *dir;
dir = itable[INTERP_SLOT_DIR].value;
if (avoid_alias(dir)) {
logerror("'%s': aliased", dir);
return NULL;
}
if (*dir == '~') {
if (!user_path) {
logerror("'%s': User-path not allowed", dir);
return NULL;
}
if (*user_path) {
/* Got either "~alice" or "~alice/foo";
* rewrite them to "~alice/%s" or
* "~alice/%s/foo".
*/
int namlen, restlen = strlen(dir);
char *slash = strchr(dir, '/');
if (!slash)
slash = dir + restlen;
namlen = slash - dir;
restlen -= namlen;
loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
snprintf(rpath, PATH_MAX, "%.*s/%s%.*s",
namlen, dir, user_path, restlen, slash);
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;
}
snprintf(rpath, PATH_MAX, "%s%s", base_path, dir);
dir = rpath;
}
do {
path = enter_repo(dir, strict_paths);
if (path)
break;
/*
* if we fail and base_path_relaxed is enabled, try without
* prefixing the base path
*/
if (base_path && base_path_relaxed && !retried_path) {
dir = itable[INTERP_SLOT_DIR].value;
retried_path = 1;
continue;
}
break;
} while (1);
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 <= pathlen &&
!memcmp(*pp, path, len) &&
(path[len] == '\0' ||
(!strict_paths && path[len] == '/')))
return path;
}
}
else {
/* be backwards compatible */
if (!strict_paths)
return path;
}
logerror("'%s': not in whitelist", path);
return NULL; /* Fallthrough. Deny by default */
}
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 (!prefixcmp(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 run_service(struct interp *itable, struct daemon_service *service)
{
const char *path;
int enabled = service->enabled;
loginfo("Request %s for '%s'",
service->name,
itable[INTERP_SLOT_DIR].value);
if (!enabled && !service->overridable) {
logerror("'%s': service not enabled.", service->name);
errno = EACCES;
return -1;
}
if (!(path = path_ok(itable)))
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.
*
* 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;
}
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 */
execl_git_cmd("upload-pack", "--strict", timeout_buf, ".", NULL);
return -1;
}
static int upload_archive(void)
{
execl_git_cmd("upload-archive", ".", NULL);
return -1;
}
static int receive_pack(void)
{
execl_git_cmd("receive-pack", ".", NULL);
return -1;
}
static struct daemon_service daemon_service[] = {
{ "upload-archive", "uploadarch", upload_archive, 0, 1 },
{ "upload-pack", "uploadpack", upload_pack, 1, 1 },
{ "receive-pack", "receivepack", receive_pack, 0, 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 squirreled 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;
}
}
}
static 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;
if (!hp)
return;
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, i;
if (addr) {
char addrbuf[256] = "";
int port = -1;
if (addr->sa_family == AF_INET) {
struct sockaddr_in *sin_addr = (void *) addr;
inet_ntop(addr->sa_family, &sin_addr->sin_addr, addrbuf, sizeof(addrbuf));
port = ntohs(sin_addr->sin_port);
#ifndef NO_IPV6
} else if (addr && addr->sa_family == AF_INET6) {
struct sockaddr_in6 *sin6_addr = (void *) addr;
char *buf = addrbuf;
*buf++ = '['; *buf = '\0'; /* stpcpy() is cool */
inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(addrbuf) - 1);
strcat(buf, "]");
port = ntohs(sin6_addr->sin6_port);
#endif
}
loginfo("Connection from %s:%d", addrbuf, port);
}
alarm(init_timeout ? init_timeout : timeout);
pktlen = packet_read_line(0, line, sizeof(line));
alarm(0);
len = strlen(line);
if (pktlen != len)
loginfo("Extended attributes (%d bytes) exist <%.*s>",
(int) pktlen - len,
(int) pktlen - len, line + len + 1);
if (len && line[len-1] == '\n') {
line[--len] = 0;
pktlen--;
}
/*
* 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 (!prefixcmp(line, "git-") &&
!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;
}
/*
* We count spawned/reaped separately, just to avoid any
* races when updating them from signals. The SIGCHLD handler
* will only update children_reaped, and the fork logic will
* only update children_spawned.
*
* MAX_CHILDREN should be a power-of-two to make the modulus
* operation cheap. It should also be at least twice
* the maximum number of connections we will ever allow.
*/
#define MAX_CHILDREN 128
static int max_connections = 25;
/* These are updated by the signal handler */
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;
static unsigned int children_deleted;
static struct child {
pid_t pid;
int addrlen;
struct sockaddr_storage address;
} live_child[MAX_CHILDREN];
static void add_child(int idx, pid_t pid, struct sockaddr *addr, int addrlen)
{
live_child[idx].pid = pid;
live_child[idx].addrlen = addrlen;
memcpy(&live_child[idx].address, addr, addrlen);
}
/*
* Walk from "deleted" to "spawned", and remove child "pid".
*
* We move everything up by one, since the new "deleted" will
* be one higher.
*/
static void remove_child(pid_t pid, unsigned deleted, unsigned spawned)
{
struct child n;
deleted %= MAX_CHILDREN;
spawned %= MAX_CHILDREN;
if (live_child[deleted].pid == pid) {
live_child[deleted].pid = -1;
return;
}
n = live_child[deleted];
for (;;) {
struct child m;
deleted = (deleted + 1) % MAX_CHILDREN;
if (deleted == spawned)
die("could not find dead child %d\n", pid);
m = live_child[deleted];
live_child[deleted] = n;
if (m.pid == pid)
return;
n = m;
}
}
/*
* This gets called if the number of connections grows
* past "max_connections".
*
* We _should_ start off by searching for connections
* from the same IP, and if there is some address wth
* multiple connections, we should kill that first.
*
* As it is, we just "randomly" kill 25% of the connections,
* and our pseudo-random generator sucks too. I have no
* shame.
*
* Really, this is just a place-holder for a _real_ algorithm.
*/
static void kill_some_children(int signo, unsigned start, unsigned stop)
{
start %= MAX_CHILDREN;
stop %= MAX_CHILDREN;
while (start != stop) {
if (!(start & 3))
kill(live_child[start].pid, signo);
start = (start + 1) % MAX_CHILDREN;
}
}
static void check_max_connections(void)
{
for (;;) {
int active;
unsigned spawned, reaped, deleted;
spawned = children_spawned;
reaped = children_reaped;
deleted = children_deleted;
while (deleted < reaped) {
pid_t pid = dead_child[deleted % MAX_CHILDREN];
remove_child(pid, deleted, spawned);
deleted++;
}
children_deleted = deleted;
active = spawned - deleted;
if (active <= max_connections)
break;
/* Kill some unstarted connections with SIGTERM */
kill_some_children(SIGTERM, deleted, spawned);
if (active <= max_connections << 1)
break;
/* If the SIGTERM thing isn't helping use SIGKILL */
kill_some_children(SIGKILL, deleted, spawned);
sleep(1);
}
}
static void handle(int incoming, struct sockaddr *addr, int addrlen)
{
pid_t pid = fork();
if (pid) {
unsigned idx;
close(incoming);
if (pid < 0)
return;
idx = children_spawned % MAX_CHILDREN;
children_spawned++;
add_child(idx, pid, addr, addrlen);
check_max_connections();
return;
}
dup2(incoming, 0);
dup2(incoming, 1);
close(incoming);
exit(execute(addr));
}
static void child_handler(int signo)
{
for (;;) {
int status;
pid_t pid = waitpid(-1, &status, WNOHANG);
if (pid > 0) {
unsigned reaped = children_reaped;
dead_child[reaped % MAX_CHILDREN] = pid;
children_reaped = reaped + 1;
/* XXX: Custom logging, since we don't wanna getpid() */
if (verbose) {
const char *dead = "";
if (!WIFEXITED(status) || WEXITSTATUS(status) > 0)
dead = " (with error)";
if (log_syslog)
syslog(LOG_INFO, "[%d] Disconnected%s", pid, dead);
else
fprintf(stderr, "[%d] Disconnected%s\n", pid, dead);
}
continue;
}
break;
}
}
static int set_reuse_addr(int sockfd)
{
int on = 1;
if (!reuseaddr)
return 0;
return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
&on, sizeof(on));
}
#ifndef NO_IPV6
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;
long flags;
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(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;
sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
if (sockfd < 0)
continue;
if (sockfd >= FD_SETSIZE) {
error("too large socket descriptor.");
close(sockfd);
continue;
}
#ifdef IPV6_V6ONLY
if (ai->ai_family == AF_INET6) {
int on = 1;
setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
&on, sizeof(on));
/* Note: error is not fatal */
}
#endif
if (set_reuse_addr(sockfd)) {
close(sockfd);
continue;
}
if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
close(sockfd);
continue; /* not fatal */
}
if (listen(sockfd, 5) < 0) {
close(sockfd);
continue; /* not fatal */
}
flags = fcntl(sockfd, F_GETFD, 0);
if (flags >= 0)
fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
socklist = xrealloc(socklist, sizeof(int) * (socknum + 1));
socklist[socknum++] = sockfd;
if (maxfd < sockfd)
maxfd = sockfd;
}
freeaddrinfo(ai0);
*socklist_p = socklist;
return socknum;
}
#else /* NO_IPV6 */
static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
{
struct sockaddr_in sin;
int sockfd;
long flags;
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;
if (set_reuse_addr(sockfd)) {
close(sockfd);
return 0;
}
if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
close(sockfd);
return 0;
}
if (listen(sockfd, 5) < 0) {
close(sockfd);
return 0;
}
flags = fcntl(sockfd, F_GETFD, 0);
if (flags >= 0)
fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
*socklist_p = xmalloc(sizeof(int));
**socklist_p = sockfd;
return 1;
}
#endif
static int service_loop(int socknum, int *socklist)
{
struct pollfd *pfd;
int i;
pfd = xcalloc(socknum, sizeof(struct pollfd));
for (i = 0; i < socknum; i++) {
pfd[i].fd = socklist[i];
pfd[i].events = POLLIN;
}
signal(SIGCHLD, child_handler);
for (;;) {
int i;
if (poll(pfd, socknum, -1) < 0) {
if (errno != EINTR) {
error("poll failed, resuming: %s",
strerror(errno));
sleep(1);
}
continue;
}
for (i = 0; i < socknum; i++) {
if (pfd[i].revents & POLLIN) {
struct sockaddr_storage ss;
unsigned int sslen = sizeof(ss);
int incoming = accept(pfd[i].fd, (struct sockaddr *)&ss, &sslen);
if (incoming < 0) {
switch (errno) {
case EAGAIN:
case EINTR:
case ECONNABORTED:
continue;
default:
die("accept returned %s", strerror(errno));
}
}
handle(incoming, (struct sockaddr *)&ss, sslen);
}
}
}
}
/* if any standard file descriptor is missing open it to /dev/null */
static void sanitize_stdfds(void)
{
int fd = open("/dev/null", O_RDWR, 0);
while (fd != -1 && fd < 2)
fd = dup(fd);
if (fd == -1)
die("open /dev/null or dup failed: %s", strerror(errno));
if (fd > 2)
close(fd);
}
static void daemonize(void)
{
switch (fork()) {
case 0:
break;
case -1:
die("fork failed: %s", strerror(errno));
default:
exit(0);
}
if (setsid() == -1)
die("setsid failed: %s", strerror(errno));
close(0);
close(1);
close(2);
sanitize_stdfds();
}
static void store_pid(const char *path)
{
FILE *f = fopen(path, "w");
if (!f)
die("cannot open pid file %s: %s", path, strerror(errno));
if (fprintf(f, "%d\n", getpid()) < 0 || fclose(f) != 0)
die("failed to write pid file %s: %s", path, strerror(errno));
}