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Improve logging
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- Log everything to stderr - this has many advantages: much easier to
  understand what happened before errors, much easier to understand the
  daemon state, since stderr is line buffered, so events (e.g. start,
  stop, connect, disconnect) are logged immediately. Easier to get logs
  from users.
- Replace fprintf and printf with logging macros (ERRORF, ERROR, INFO)
- Replace perror with ERRORN, showing the same output an error log.
- Use prefix for all logs ("DEBUG|", "INFO |", "ERROR|") to make the
  meaning of the message clear, and make all log message
  aligned nicely.
- Remove unneeded log for vmnet_return_t when we get VMNET_SUCCESS
- Replace print_vmnet_status() with vmnet_strerror() returning readable
  error name. Callers use ERRORF() to log the vmnet function name,
  return value and error name.
- Log socket length when it is too long
- Log the signal name and number
- Don't use perror() for logging errors from function snot setting errno
- Don't log same error twice (once in a function, second in the caller)

Signed-off-by: Nir Soffer <[email protected]>
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@nirs
nirs committed Nov 7, 2024
1 parent 273726b commit 455138f
Showing 1 changed file with 61 additions and 65 deletions.
126 changes: 61 additions & 65 deletions main.c
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Original file line number Diff line number Diff line change
Expand Up @@ -26,38 +26,33 @@ static bool debug = false;
fprintf(stderr, "DEBUG| " fmt "\n", __VA_ARGS__); \
} while (0)

static void print_vmnet_status(const char *func, vmnet_return_t v) {
#define INFOF(fmt, ...) fprintf(stderr, "INFO | " fmt "\n", __VA_ARGS__)
#define ERROR(msg) fprintf(stderr, "ERROR| " msg "\n")
#define ERRORF(fmt, ...) fprintf(stderr, "ERROR| " fmt "\n", __VA_ARGS__)
#define ERRORN(name) ERRORF(name ": %s", strerror(errno))

static const char *vmnet_strerror(vmnet_return_t v) {
switch (v) {
case VMNET_SUCCESS:
DEBUGF("%s(): vmnet_return_t VMNET_SUCCESS", func);
break;
return "VMNET_SUCCESS";
case VMNET_FAILURE:
fprintf(stderr, "%s(): vmnet_return_t VMNET_FAILURE\n", func);
break;
return "VMNET_FAILURE";
case VMNET_MEM_FAILURE:
fprintf(stderr, "%s(): vmnet_return_t VMNET_MEM_FAILURE\n", func);
break;
return "VMNET_MEM_FAILURE";
case VMNET_INVALID_ARGUMENT:
fprintf(stderr, "%s(): vmnet_return_t VMNET_INVALID_ARGUMENT\n", func);
break;
return "VMNET_INVALID_ARGUMENT";
case VMNET_SETUP_INCOMPLETE:
fprintf(stderr, "%s(): vmnet_return_t VMNET_SETUP_INCOMPLETE\n", func);
break;
return "VMNET_SETUP_INCOMPLETE";
case VMNET_INVALID_ACCESS:
fprintf(stderr, "%s(): vmnet_return_t VMNET_INVALID_ACCESS\n", func);
break;
return "VMNET_INVALID_ACCESS";
case VMNET_PACKET_TOO_BIG:
fprintf(stderr, "%s(): vmnet_return_t VMNET_PACKET_TOO_BIG\n", func);
break;
return "VMNET_PACKET_TOO_BIG";
case VMNET_BUFFER_EXHAUSTED:
fprintf(stderr, "%s(): vmnet_return_t VMNET_BUFFER_EXHAUSTED\n", func);
break;
return "VMNET_BUFFER_EXHAUSTED";
case VMNET_TOO_MANY_PACKETS:
fprintf(stderr, "%s(): vmnet_return_t VMNET_TOO_MANY_PACKETS\n", func);
break;
return "VMNET_TOO_MANY_PACKETS";
default:
fprintf(stderr, "%s(): vmnet_return_t %d\n", func, v);
break;
return "(unknown status)";
}
}

Expand All @@ -67,17 +62,17 @@ static void print_vmnet_start_param(xpc_object_t param) {
xpc_dictionary_apply(param, ^bool(const char *key, xpc_object_t value) {
xpc_type_t t = xpc_get_type(value);
if (t == XPC_TYPE_UINT64)
printf("* %s: %lld\n", key, xpc_uint64_get_value(value));
INFOF("* %s: %lld", key, xpc_uint64_get_value(value));
else if (t == XPC_TYPE_INT64)
printf("* %s: %lld\n", key, xpc_int64_get_value(value));
INFOF("* %s: %lld", key, xpc_int64_get_value(value));
else if (t == XPC_TYPE_STRING)
printf("* %s: %s\n", key, xpc_string_get_string_ptr(value));
INFOF("* %s: %s", key, xpc_string_get_string_ptr(value));
else if (t == XPC_TYPE_UUID) {
char uuid_str[36 + 1];
uuid_unparse(xpc_uuid_get_bytes(value), uuid_str);
printf("* %s: %s\n", key, uuid_str);
INFOF("* %s: %s", key, uuid_str);
} else
printf("* %s: (unknown type)\n", key);
INFOF("* %s: (unknown type)", key);
return true;
});
}
Expand Down Expand Up @@ -136,29 +131,28 @@ static void _on_vmnet_packets_available(interface_ref iface, int64_t buf_count,
// TODO: use prealloced pool
struct vmpktdesc *pdv = calloc(buf_count, sizeof(struct vmpktdesc));
if (pdv == NULL) {
perror("calloc(estim_count, sizeof(struct vmpktdesc)");
ERRORN("calloc(estim_count, sizeof(struct vmpktdesc)");
goto done;
}
for (int i = 0; i < buf_count; i++) {
pdv[i].vm_flags = 0;
pdv[i].vm_pkt_size = max_bytes;
pdv[i].vm_pkt_iovcnt = 1, pdv[i].vm_pkt_iov = malloc(sizeof(struct iovec));
if (pdv[i].vm_pkt_iov == NULL) {
perror("malloc(sizeof(struct iovec))");
ERRORN("malloc(sizeof(struct iovec))");
goto done;
}
pdv[i].vm_pkt_iov->iov_base = malloc(max_bytes);
if (pdv[i].vm_pkt_iov->iov_base == NULL) {
perror("malloc(max_bytes)");
ERRORN("malloc(max_bytes)");
goto done;
}
pdv[i].vm_pkt_iov->iov_len = max_bytes;
}
int received_count = buf_count;
vmnet_return_t read_status = vmnet_read(iface, pdv, &received_count);
print_vmnet_status(__FUNCTION__, read_status);
if (read_status != VMNET_SUCCESS) {
perror("vmnet_read");
ERRORF("vmnet_read: [%d] %s", read_status, vmnet_strerror(read_status));
goto done;
}

Expand Down Expand Up @@ -200,7 +194,7 @@ static void _on_vmnet_packets_available(interface_ref iface, int64_t buf_count,
"header)",
i, written);
if (written < 0) {
perror("writev");
ERRORN("writev");
goto done;
}
}
Expand Down Expand Up @@ -235,11 +229,11 @@ static void on_vmnet_packets_available(interface_ref iface, int64_t estim_count,
}

static interface_ref start(struct state *state, struct cli_options *cliopt) {
printf("Initializing vmnet.framework (mode %d)\n", cliopt->vmnet_mode);
INFOF("Initializing vmnet.framework (mode %d)", cliopt->vmnet_mode);
xpc_object_t dict = xpc_dictionary_create(NULL, NULL, 0);
xpc_dictionary_set_uint64(dict, vmnet_operation_mode_key, cliopt->vmnet_mode);
if (cliopt->vmnet_interface != NULL) {
printf("Using network interface \"%s\"\n", cliopt->vmnet_interface);
INFOF("Using network interface \"%s\"", cliopt->vmnet_interface);
xpc_dictionary_set_string(dict, vmnet_shared_interface_name_key,
cliopt->vmnet_interface);
}
Expand Down Expand Up @@ -278,10 +272,10 @@ static interface_ref start(struct state *state, struct cli_options *cliopt) {
dispatch_semaphore_signal(sem);
});
dispatch_semaphore_wait(sem, DISPATCH_TIME_FOREVER);
print_vmnet_status(__FUNCTION__, status);
dispatch_release(q);
xpc_release(dict);
if (status != VMNET_SUCCESS) {
ERRORF("vmnet_start_interface: [%d] %s", status, vmnet_strerror(status));
return NULL;
}

Expand All @@ -301,7 +295,7 @@ static interface_ref start(struct state *state, struct cli_options *cliopt) {

static sigjmp_buf jmpbuf;
static void signalhandler(int signal) {
printf("\nReceived signal %d\n", signal);
INFOF("Received signal: %s", strsignal(signal));
siglongjmp(jmpbuf, 1);
}

Expand All @@ -318,9 +312,11 @@ static void stop(interface_ref iface) {
dispatch_semaphore_signal(sem);
});
dispatch_semaphore_wait(sem, DISPATCH_TIME_FOREVER);
print_vmnet_status(__FUNCTION__, status);
dispatch_release(q);
// TODO: release event_q ?
if (status != VMNET_SUCCESS) {
ERRORF("vmnet_stop_interface: [%d] %s", status, vmnet_strerror(status));
}
}

static int socket_bindlisten(const char *socket_path,
Expand All @@ -330,40 +326,41 @@ static int socket_bindlisten(const char *socket_path,
memset(&addr, 0, sizeof(addr));
unlink(socket_path); /* avoid EADDRINUSE */
if ((fd = socket(PF_LOCAL, SOCK_STREAM, 0)) < 0) {
perror("socket");
ERRORN("socket");
goto err;
}
addr.sun_family = PF_LOCAL;
if (strlen(socket_path) + 1 > sizeof(addr.sun_path)) {
fprintf(stderr, "the socket path is too long\n");
size_t socket_len = strlen(socket_path);
if (socket_len + 1 > sizeof(addr.sun_path)) {
ERRORF("the socket path is too long: %zu", socket_len);
goto err;
}
strncpy(addr.sun_path, socket_path, sizeof(addr.sun_path) - 1);
if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
perror("bind");
ERRORN("bind");
goto err;
}
if (listen(fd, 0) < 0) {
perror("listen");
ERRORN("listen");
goto err;
}
if (socket_group != NULL) {
errno = 0;
struct group *grp = getgrnam(socket_group); /* Do not free */
if (grp == NULL) {
if (errno != 0)
perror("getgrnam");
ERRORN("getgrnam");
else
fprintf(stderr, "unknown group name \"%s\"\n", socket_group);
ERRORF("unknown group name \"%s\"", socket_group);
goto err;
}
/* fchown can't be used (EINVAL) */
if (chown(socket_path, -1, grp->gr_gid) < 0) {
perror("chown");
ERRORN("chown");
goto err;
}
if (chmod(socket_path, 0770) < 0) {
perror("chmod");
ERRORN("chmod");
goto err;
}
}
Expand All @@ -386,12 +383,12 @@ int main(int argc, char *argv[]) {
struct cli_options *cliopt = cli_options_parse(argc, argv);
assert(cliopt != NULL);
if (geteuid() != 0) {
fprintf(stderr, "WARNING: Running without root. This is very unlikely to "
"work. See README.md .\n");
ERROR("WARNING: Running without root. This is very unlikely to "
"work: See README.md");
}
if (geteuid() != getuid()) {
fprintf(stderr, "WARNING: Seems running with SETUID. This is insecure and "
"highly discouraged. See README.md .\n");
ERROR("WARNING: Seems running with SETUID. This is insecure and "
"highly discouraged: See README.md");
}

if (sigsetjmp(jmpbuf, 1) != 0) {
Expand All @@ -409,15 +406,15 @@ int main(int argc, char *argv[]) {
pid_fd = open(cliopt->pidfile,
O_WRONLY | O_CREAT | O_EXLOCK | O_TRUNC | O_NONBLOCK, 0644);
if (pid_fd == -1) {
perror("pidfile_open");
ERRORN("pidfile_open");
goto done;
}
}
DEBUGF("Opening socket \"%s\" (for UNIX group \"%s\")", cliopt->socket_path,
cliopt->socket_group);
listen_fd = socket_bindlisten(cliopt->socket_path, cliopt->socket_group);
if (listen_fd < 0) {
perror("socket_bindlisten");
ERRORN("socket_bindlisten");
goto done;
}

Expand All @@ -426,23 +423,23 @@ int main(int argc, char *argv[]) {
state.sem = dispatch_semaphore_create(1);
iface = start(&state, cliopt);
if (iface == NULL) {
perror("start");
// Error already logged.
goto done;
}

if (pid_fd != -1) {
char pid[20];
snprintf(pid, sizeof(pid), "%u", getpid());
if (write(pid_fd, pid, strlen(pid)) != (ssize_t)strlen(pid)) {
perror("pidfile_write");
ERRORN("write");
goto done;
}
}

while (1) {
int accept_fd = accept(listen_fd, NULL, NULL);
if (accept_fd < 0) {
perror("accept");
ERRORN("accept");
goto done;
}
struct state *state_p = &state;
Expand All @@ -469,12 +466,12 @@ int main(int argc, char *argv[]) {
}

static void on_accept(struct state *state, int accept_fd, interface_ref iface) {
printf("Accepted a connection (fd %d)\n", accept_fd);
INFOF("Accepted a connection (fd %d)", accept_fd);
state_add_socket_fd(state, accept_fd);
size_t buf_len = 64 * 1024;
void *buf = malloc(buf_len);
if (buf == NULL) {
perror("malloc");
ERRORN("malloc");
goto done;
}
for (uint64_t i = 0;; i++) {
Expand All @@ -483,24 +480,24 @@ static void on_accept(struct state *state, int accept_fd, interface_ref iface) {
uint32_t header_be = 0;
ssize_t header_received = read(accept_fd, &header_be, 4);
if (header_received < 0) {
perror("read[header]");
ERRORN("read[header]");
goto done;
}
if (header_received == 0) {
// EOF according to man page of read.
fprintf(stderr, "Connection closed by peer (fd %d)\n", accept_fd);
INFOF("Connection closed by peer (fd %d)", accept_fd);
goto done;
}
uint32_t header = ntohl(header_be);
assert(header <= buf_len);
ssize_t received = read(accept_fd, buf, header);
if (received < 0) {
perror("read");
ERRORN("read[body]");
goto done;
}
if (received == 0) {
// EOF according to man page of read.
fprintf(stderr, "Connection closed by peer (fd %d)\n", accept_fd);
INFOF("Connection closed by peer (fd %d)", accept_fd);
goto done;
}
assert(received == header);
Expand All @@ -520,9 +517,8 @@ static void on_accept(struct state *state, int accept_fd, interface_ref iface) {
DEBUGF("[Socket-to-VMNET i=%lld] Sending to VMNET: %ld bytes", i,
pd.vm_pkt_size);
vmnet_return_t write_status = vmnet_write(iface, &pd, &written_count);
print_vmnet_status(__FUNCTION__, write_status);
if (write_status != VMNET_SUCCESS) {
perror("vmnet_write");
ERRORF("vmnet_write: [%d] %s", write_status, vmnet_strerror(write_status));
goto done;
}
DEBUGF("[Socket-to-VMNET i=%lld] Sent to VMNET: %ld bytes", i,
Expand Down Expand Up @@ -555,13 +551,13 @@ static void on_accept(struct state *state, int accept_fd, interface_ref iface) {
"bytes (including uint32be header)",
i, accept_fd, conn->socket_fd, written);
if (written < 0) {
perror("writev");
ERRORN("writev");
continue;
}
}
}
done:
printf("Closing a connection (fd %d)\n", accept_fd);
INFOF("Closing a connection (fd %d)", accept_fd);
state_remove_socket_fd(state, accept_fd);
close(accept_fd);
if (buf != NULL) {
Expand Down

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