tagstruct: Refactor writing/reading basic types

While adding functions for writing and reading pa_bvolume structs, I
found myself wondering if I could make it simpler to write and read
the basic types that a pa_bvolume consists of, without having to worry
about network byte ordering, remembering to call extend() and getting
the length and read index adjustments just right. This is what I came
up with.

There is a functional change too: previously the
pa_tagstruct_get_foo() functions didn't modify the read index in case
of errors, but now, due to read_tag() modifying the read index at an
early stage, the read index gets modified also in case of errors. I
have checked the call sites, and I believe there's no code that would
rely on the "no read index modification on error" property of the old
functions. If reading anything from a tagstruct fails, the whole
tagstruct is considered invalid (typically resulting in a protocol
error and client connection teardown).
This commit is contained in:
Tanu Kaskinen 2015-02-17 21:40:13 +02:00 committed by David Henningsson
parent aa3a27d5cd
commit 390b7db95d

View file

@ -83,7 +83,7 @@ uint8_t* pa_tagstruct_free_data(pa_tagstruct*t, size_t *l) {
return p;
}
static void extend(pa_tagstruct*t, size_t l) {
static inline void extend(pa_tagstruct*t, size_t l) {
pa_assert(t);
pa_assert(t->dynamic);
@ -93,133 +93,168 @@ static void extend(pa_tagstruct*t, size_t l) {
t->data = pa_xrealloc(t->data, t->allocated = t->length+l+100);
}
static void write_u8(pa_tagstruct *t, uint8_t u) {
extend(t, 1);
t->data[t->length++] = u;
}
static int read_u8(pa_tagstruct *t, uint8_t *u) {
if (t->rindex + 1 > t->length)
return -1;
*u = t->data[t->rindex++];
return 0;
}
static void write_u32(pa_tagstruct *t, uint32_t u) {
extend(t, 4);
u = htonl(u);
memcpy(t->data + t->length, &u, 4);
t->length += 4;
}
static int read_u32(pa_tagstruct *t, uint32_t *u) {
if (t->rindex + 4 > t->length)
return -1;
memcpy(u, t->data + t->rindex, 4);
*u = ntohl(*u);
t->rindex += 4;
return 0;
}
static void write_u64(pa_tagstruct *t, uint64_t u) {
write_u32(t, u >> 32);
write_u32(t, u);
}
static int read_u64(pa_tagstruct *t, uint64_t *u) {
uint32_t tmp;
if (read_u32(t, &tmp) < 0)
return -1;
*u = ((uint64_t) tmp) << 32;
if (read_u32(t, &tmp) < 0)
return -1;
*u |= tmp;
return 0;
}
static int read_s64(pa_tagstruct *t, int64_t *u) {
uint32_t tmp;
if (read_u32(t, &tmp) < 0)
return -1;
*u = (int64_t) (((uint64_t) tmp) << 32);
if (read_u32(t, &tmp) < 0)
return -1;
*u |= (int64_t) tmp;
return 0;
}
static void write_arbitrary(pa_tagstruct *t, const void *p, size_t len) {
extend(t, len);
if (len > 0)
memcpy(t->data + t->length, p, len);
t->length += len;
}
static int read_arbitrary(pa_tagstruct *t, const void **p, size_t length) {
if (t->rindex + length > t->length)
return -1;
*p = t->data + t->rindex;
t->rindex += length;
return 0;
}
void pa_tagstruct_puts(pa_tagstruct*t, const char *s) {
size_t l;
pa_assert(t);
if (s) {
l = strlen(s)+2;
extend(t, l);
t->data[t->length] = PA_TAG_STRING;
strcpy((char*) (t->data+t->length+1), s);
t->length += l;
} else {
extend(t, 1);
t->data[t->length] = PA_TAG_STRING_NULL;
t->length += 1;
}
write_u8(t, PA_TAG_STRING);
l = strlen(s)+1;
write_arbitrary(t, s, l);
} else
write_u8(t, PA_TAG_STRING_NULL);
}
void pa_tagstruct_putu32(pa_tagstruct*t, uint32_t i) {
pa_assert(t);
extend(t, 5);
t->data[t->length] = PA_TAG_U32;
i = htonl(i);
memcpy(t->data+t->length+1, &i, 4);
t->length += 5;
write_u8(t, PA_TAG_U32);
write_u32(t, i);
}
void pa_tagstruct_putu8(pa_tagstruct*t, uint8_t c) {
pa_assert(t);
extend(t, 2);
t->data[t->length] = PA_TAG_U8;
*(t->data+t->length+1) = c;
t->length += 2;
write_u8(t, PA_TAG_U8);
write_u8(t, c);
}
void pa_tagstruct_put_sample_spec(pa_tagstruct *t, const pa_sample_spec *ss) {
uint32_t rate;
pa_assert(t);
pa_assert(ss);
extend(t, 7);
t->data[t->length] = PA_TAG_SAMPLE_SPEC;
t->data[t->length+1] = (uint8_t) ss->format;
t->data[t->length+2] = ss->channels;
rate = htonl(ss->rate);
memcpy(t->data+t->length+3, &rate, 4);
t->length += 7;
write_u8(t, PA_TAG_SAMPLE_SPEC);
write_u8(t, ss->format);
write_u8(t, ss->channels);
write_u32(t, ss->rate);
}
void pa_tagstruct_put_arbitrary(pa_tagstruct *t, const void *p, size_t length) {
uint32_t tmp;
pa_assert(t);
pa_assert(p);
extend(t, 5+length);
t->data[t->length] = PA_TAG_ARBITRARY;
tmp = htonl((uint32_t) length);
memcpy(t->data+t->length+1, &tmp, 4);
if (length)
memcpy(t->data+t->length+5, p, length);
t->length += 5+length;
write_u8(t, PA_TAG_ARBITRARY);
write_u32(t, length);
write_arbitrary(t, p, length);
}
void pa_tagstruct_put_boolean(pa_tagstruct*t, bool b) {
pa_assert(t);
extend(t, 1);
t->data[t->length] = (uint8_t) (b ? PA_TAG_BOOLEAN_TRUE : PA_TAG_BOOLEAN_FALSE);
t->length += 1;
write_u8(t, b ? PA_TAG_BOOLEAN_TRUE : PA_TAG_BOOLEAN_FALSE);
}
void pa_tagstruct_put_timeval(pa_tagstruct*t, const struct timeval *tv) {
uint32_t tmp;
pa_assert(t);
extend(t, 9);
t->data[t->length] = PA_TAG_TIMEVAL;
tmp = htonl((uint32_t) tv->tv_sec);
memcpy(t->data+t->length+1, &tmp, 4);
tmp = htonl((uint32_t) tv->tv_usec);
memcpy(t->data+t->length+5, &tmp, 4);
t->length += 9;
write_u8(t, PA_TAG_TIMEVAL);
write_u32(t, tv->tv_sec);
write_u32(t, tv->tv_usec);
}
void pa_tagstruct_put_usec(pa_tagstruct*t, pa_usec_t u) {
uint32_t tmp;
pa_assert(t);
extend(t, 9);
t->data[t->length] = PA_TAG_USEC;
tmp = htonl((uint32_t) (u >> 32));
memcpy(t->data+t->length+1, &tmp, 4);
tmp = htonl((uint32_t) u);
memcpy(t->data+t->length+5, &tmp, 4);
t->length += 9;
write_u8(t, PA_TAG_USEC);
write_u64(t, u);
}
void pa_tagstruct_putu64(pa_tagstruct*t, uint64_t u) {
uint32_t tmp;
pa_assert(t);
extend(t, 9);
t->data[t->length] = PA_TAG_U64;
tmp = htonl((uint32_t) (u >> 32));
memcpy(t->data+t->length+1, &tmp, 4);
tmp = htonl((uint32_t) u);
memcpy(t->data+t->length+5, &tmp, 4);
t->length += 9;
write_u8(t, PA_TAG_U64);
write_u64(t, u);
}
void pa_tagstruct_puts64(pa_tagstruct*t, int64_t u) {
uint32_t tmp;
pa_assert(t);
extend(t, 9);
t->data[t->length] = PA_TAG_S64;
tmp = htonl((uint32_t) ((uint64_t) u >> 32));
memcpy(t->data+t->length+1, &tmp, 4);
tmp = htonl((uint32_t) ((uint64_t) u));
memcpy(t->data+t->length+5, &tmp, 4);
t->length += 9;
write_u8(t, PA_TAG_S64);
write_u64(t, u);
}
void pa_tagstruct_put_channel_map(pa_tagstruct *t, const pa_channel_map *map) {
@ -227,42 +262,32 @@ void pa_tagstruct_put_channel_map(pa_tagstruct *t, const pa_channel_map *map) {
pa_assert(t);
pa_assert(map);
extend(t, 2 + (size_t) map->channels);
t->data[t->length++] = PA_TAG_CHANNEL_MAP;
t->data[t->length++] = map->channels;
write_u8(t, PA_TAG_CHANNEL_MAP);
write_u8(t, map->channels);
for (i = 0; i < map->channels; i ++)
t->data[t->length++] = (uint8_t) map->map[i];
write_u8(t, map->map[i]);
}
void pa_tagstruct_put_cvolume(pa_tagstruct *t, const pa_cvolume *cvolume) {
unsigned i;
pa_volume_t vol;
pa_assert(t);
pa_assert(cvolume);
extend(t, 2 + cvolume->channels * sizeof(pa_volume_t));
t->data[t->length++] = PA_TAG_CVOLUME;
t->data[t->length++] = cvolume->channels;
write_u8(t, PA_TAG_CVOLUME);
write_u8(t, cvolume->channels);
for (i = 0; i < cvolume->channels; i ++) {
vol = htonl(cvolume->values[i]);
memcpy(t->data + t->length, &vol, sizeof(pa_volume_t));
t->length += sizeof(pa_volume_t);
}
for (i = 0; i < cvolume->channels; i ++)
write_u32(t, cvolume->values[i]);
}
void pa_tagstruct_put_volume(pa_tagstruct *t, pa_volume_t vol) {
uint32_t u;
pa_assert(t);
extend(t, 5);
t->data[t->length] = PA_TAG_VOLUME;
u = htonl((uint32_t) vol);
memcpy(t->data+t->length+1, &u, 4);
t->length += 5;
write_u8(t, PA_TAG_VOLUME);
write_u32(t, vol);
}
void pa_tagstruct_put_proplist(pa_tagstruct *t, pa_proplist *p) {
@ -270,9 +295,7 @@ void pa_tagstruct_put_proplist(pa_tagstruct *t, pa_proplist *p) {
pa_assert(t);
pa_assert(p);
extend(t, 1);
t->data[t->length++] = PA_TAG_PROPLIST;
write_u8(t, PA_TAG_PROPLIST);
for (;;) {
const char *k;
@ -295,13 +318,23 @@ void pa_tagstruct_put_format_info(pa_tagstruct *t, pa_format_info *f) {
pa_assert(t);
pa_assert(f);
extend(t, 1);
t->data[t->length++] = PA_TAG_FORMAT_INFO;
write_u8(t, PA_TAG_FORMAT_INFO);
pa_tagstruct_putu8(t, (uint8_t) f->encoding);
pa_tagstruct_put_proplist(t, f->plist);
}
static int read_tag(pa_tagstruct *t, uint8_t type) {
if (t->rindex + 1 > t->length)
return -1;
if (t->data[t->rindex] != type)
return -1;
t->rindex++;
return 0;
}
int pa_tagstruct_gets(pa_tagstruct*t, const char **s) {
int error = 0;
size_t n;
@ -319,14 +352,14 @@ int pa_tagstruct_gets(pa_tagstruct*t, const char **s) {
return 0;
}
if (t->rindex+2 > t->length)
if (read_tag(t, PA_TAG_STRING) < 0)
return -1;
if (t->data[t->rindex] != PA_TAG_STRING)
if (t->rindex + 1 > t->length)
return -1;
error = 1;
for (n = 0, c = (char*) (t->data+t->rindex+1); t->rindex+1+n < t->length; n++, c++)
for (n = 0, c = (char*) (t->data + t->rindex); t->rindex + n < t->length; n++, c++)
if (!*c) {
error = 0;
break;
@ -335,9 +368,9 @@ int pa_tagstruct_gets(pa_tagstruct*t, const char **s) {
if (error)
return -1;
*s = (char*) (t->data+t->rindex+1);
*s = (char*) (t->data + t->rindex);
t->rindex += n+2;
t->rindex += n + 1;
return 0;
}
@ -345,50 +378,40 @@ int pa_tagstruct_getu32(pa_tagstruct*t, uint32_t *i) {
pa_assert(t);
pa_assert(i);
if (t->rindex+5 > t->length)
if (read_tag(t, PA_TAG_U32) < 0)
return -1;
if (t->data[t->rindex] != PA_TAG_U32)
return -1;
memcpy(i, t->data+t->rindex+1, 4);
*i = ntohl(*i);
t->rindex += 5;
return 0;
return read_u32(t, i);
}
int pa_tagstruct_getu8(pa_tagstruct*t, uint8_t *c) {
pa_assert(t);
pa_assert(c);
if (t->rindex+2 > t->length)
if (read_tag(t, PA_TAG_U8) < 0)
return -1;
if (t->data[t->rindex] != PA_TAG_U8)
return -1;
*c = t->data[t->rindex+1];
t->rindex +=2;
return 0;
return read_u8(t, c);
}
int pa_tagstruct_get_sample_spec(pa_tagstruct *t, pa_sample_spec *ss) {
uint8_t tmp;
pa_assert(t);
pa_assert(ss);
if (t->rindex+7 > t->length)
if (read_tag(t, PA_TAG_SAMPLE_SPEC) < 0)
return -1;
if (t->data[t->rindex] != PA_TAG_SAMPLE_SPEC)
if (read_u8(t, &tmp) < 0)
return -1;
ss->format = t->data[t->rindex+1];
ss->channels = t->data[t->rindex+2];
memcpy(&ss->rate, t->data+t->rindex+3, 4);
ss->rate = ntohl(ss->rate);
ss->format = tmp;
t->rindex += 7;
return 0;
if (read_u8(t, &ss->channels) < 0)
return -1;
return read_u32(t, &ss->rate);
}
int pa_tagstruct_get_arbitrary(pa_tagstruct *t, const void **p, size_t length) {
@ -397,19 +420,13 @@ int pa_tagstruct_get_arbitrary(pa_tagstruct *t, const void **p, size_t length) {
pa_assert(t);
pa_assert(p);
if (t->rindex+5+length > t->length)
if (read_tag(t, PA_TAG_ARBITRARY) < 0)
return -1;
if (t->data[t->rindex] != PA_TAG_ARBITRARY)
if (read_u32(t, &len) < 0 || len != length)
return -1;
memcpy(&len, t->data+t->rindex+1, 4);
if (ntohl(len) != length)
return -1;
*p = t->data+t->rindex+5;
t->rindex += 5+length;
return 0;
return read_arbitrary(t, p, length);
}
int pa_tagstruct_eof(pa_tagstruct*t) {
@ -446,82 +463,55 @@ int pa_tagstruct_get_boolean(pa_tagstruct*t, bool *b) {
}
int pa_tagstruct_get_timeval(pa_tagstruct*t, struct timeval *tv) {
uint32_t tmp;
pa_assert(t);
pa_assert(tv);
if (t->rindex+9 > t->length)
if (read_tag(t, PA_TAG_TIMEVAL) < 0)
return -1;
if (t->data[t->rindex] != PA_TAG_TIMEVAL)
if (read_u32(t, &tmp) < 0)
return -1;
memcpy(&tv->tv_sec, t->data+t->rindex+1, 4);
tv->tv_sec = (time_t) ntohl((uint32_t) tv->tv_sec);
memcpy(&tv->tv_usec, t->data+t->rindex+5, 4);
tv->tv_usec = (suseconds_t) ntohl((uint32_t) tv->tv_usec);
t->rindex += 9;
tv->tv_sec = tmp;
if (read_u32(t, &tmp) < 0)
return -1;
tv->tv_usec = tmp;
return 0;
}
int pa_tagstruct_get_usec(pa_tagstruct*t, pa_usec_t *u) {
uint32_t tmp;
pa_assert(t);
pa_assert(u);
if (t->rindex+9 > t->length)
if (read_tag(t, PA_TAG_USEC) < 0)
return -1;
if (t->data[t->rindex] != PA_TAG_USEC)
return -1;
memcpy(&tmp, t->data+t->rindex+1, 4);
*u = (pa_usec_t) ntohl(tmp) << 32;
memcpy(&tmp, t->data+t->rindex+5, 4);
*u |= (pa_usec_t) ntohl(tmp);
t->rindex +=9;
return 0;
return read_u64(t, u);
}
int pa_tagstruct_getu64(pa_tagstruct*t, uint64_t *u) {
uint32_t tmp;
pa_assert(t);
pa_assert(u);
if (t->rindex+9 > t->length)
if (read_tag(t, PA_TAG_U64) < 0)
return -1;
if (t->data[t->rindex] != PA_TAG_U64)
return -1;
memcpy(&tmp, t->data+t->rindex+1, 4);
*u = (uint64_t) ntohl(tmp) << 32;
memcpy(&tmp, t->data+t->rindex+5, 4);
*u |= (uint64_t) ntohl(tmp);
t->rindex +=9;
return 0;
return read_u64(t, u);
}
int pa_tagstruct_gets64(pa_tagstruct*t, int64_t *u) {
uint32_t tmp;
pa_assert(t);
pa_assert(u);
if (t->rindex+9 > t->length)
if (read_tag(t, PA_TAG_S64) < 0)
return -1;
if (t->data[t->rindex] != PA_TAG_S64)
return -1;
memcpy(&tmp, t->data+t->rindex+1, 4);
*u = (int64_t) ((uint64_t) ntohl(tmp) << 32);
memcpy(&tmp, t->data+t->rindex+5, 4);
*u |= (int64_t) ntohl(tmp);
t->rindex +=9;
return 0;
return read_s64(t, u);
}
int pa_tagstruct_get_channel_map(pa_tagstruct *t, pa_channel_map *map) {
@ -530,149 +520,105 @@ int pa_tagstruct_get_channel_map(pa_tagstruct *t, pa_channel_map *map) {
pa_assert(t);
pa_assert(map);
if (t->rindex+2 > t->length)
if (read_tag(t, PA_TAG_CHANNEL_MAP) < 0)
return -1;
if (t->data[t->rindex] != PA_TAG_CHANNEL_MAP)
if (read_u8(t, &map->channels) < 0 || map->channels > PA_CHANNELS_MAX)
return -1;
if ((map->channels = t->data[t->rindex+1]) > PA_CHANNELS_MAX)
for (i = 0; i < map->channels; i ++) {
uint8_t tmp;
if (read_u8(t, &tmp) < 0)
return -1;
if (t->rindex+2+map->channels > t->length)
return -1;
map->map[i] = tmp;
}
for (i = 0; i < map->channels; i ++)
map->map[i] = (int8_t) t->data[t->rindex + 2 + i];
t->rindex += 2 + (size_t) map->channels;
return 0;
}
int pa_tagstruct_get_cvolume(pa_tagstruct *t, pa_cvolume *cvolume) {
unsigned i;
pa_volume_t vol;
pa_assert(t);
pa_assert(cvolume);
if (t->rindex+2 > t->length)
if (read_tag(t, PA_TAG_CVOLUME) < 0)
return -1;
if (t->data[t->rindex] != PA_TAG_CVOLUME)
return -1;
if ((cvolume->channels = t->data[t->rindex+1]) > PA_CHANNELS_MAX)
return -1;
if (t->rindex+2+cvolume->channels*sizeof(pa_volume_t) > t->length)
if (read_u8(t, &cvolume->channels) < 0 || cvolume->channels > PA_CHANNELS_MAX)
return -1;
for (i = 0; i < cvolume->channels; i ++) {
memcpy(&vol, t->data + t->rindex + 2 + i * sizeof(pa_volume_t), sizeof(pa_volume_t));
cvolume->values[i] = (pa_volume_t) ntohl(vol);
if (read_u32(t, &cvolume->values[i]) < 0)
return -1;
}
t->rindex += 2 + cvolume->channels * sizeof(pa_volume_t);
return 0;
}
int pa_tagstruct_get_volume(pa_tagstruct*t, pa_volume_t *vol) {
uint32_t u;
pa_assert(t);
pa_assert(vol);
if (t->rindex+5 > t->length)
if (read_tag(t, PA_TAG_VOLUME) < 0)
return -1;
if (t->data[t->rindex] != PA_TAG_VOLUME)
return -1;
memcpy(&u, t->data+t->rindex+1, 4);
*vol = (pa_volume_t) ntohl(u);
t->rindex += 5;
return 0;
return read_u32(t, vol);
}
int pa_tagstruct_get_proplist(pa_tagstruct *t, pa_proplist *p) {
size_t saved_rindex;
pa_assert(t);
if (t->rindex+1 > t->length)
if (read_tag(t, PA_TAG_PROPLIST) < 0)
return -1;
if (t->data[t->rindex] != PA_TAG_PROPLIST)
return -1;
saved_rindex = t->rindex;
t->rindex++;
for (;;) {
const char *k;
const void *d;
uint32_t length;
if (pa_tagstruct_gets(t, &k) < 0)
goto fail;
return -1;
if (!k)
break;
if (!pa_proplist_key_valid(k))
goto fail;
return -1;
if (pa_tagstruct_getu32(t, &length) < 0)
goto fail;
return -1;
if (length > MAX_TAG_SIZE)
goto fail;
return -1;
if (pa_tagstruct_get_arbitrary(t, &d, length) < 0)
goto fail;
return -1;
if (p)
pa_assert_se(pa_proplist_set(p, k, d, length) >= 0);
}
return 0;
fail:
t->rindex = saved_rindex;
return -1;
}
int pa_tagstruct_get_format_info(pa_tagstruct *t, pa_format_info *f) {
size_t saved_rindex;
uint8_t encoding;
pa_assert(t);
pa_assert(f);
if (t->rindex+1 > t->length)
if (read_tag(t, PA_TAG_FORMAT_INFO) < 0)
return -1;
if (t->data[t->rindex] != PA_TAG_FORMAT_INFO)
return -1;
saved_rindex = t->rindex;
t->rindex++;
if (pa_tagstruct_getu8(t, &encoding) < 0)
goto fail;
return -1;
f->encoding = encoding;
if (pa_tagstruct_get_proplist(t, f->plist) < 0)
goto fail;
return 0;
fail:
t->rindex = saved_rindex;
return -1;
return pa_tagstruct_get_proplist(t, f->plist);
}
void pa_tagstruct_put(pa_tagstruct *t, ...) {