| -rw-r--r-- | pumpkin/TFTPPacket.m | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/pumpkin/TFTPPacket.m b/pumpkin/TFTPPacket.m new file mode 100644 index 0000000..73f5995 --- a/dev/null +++ b/pumpkin/TFTPPacket.m @@ -0,0 +1,203 @@ + +#import "TFTPPacket.h" + +@interface NSDictionary (TFTPOptions) + +- (size_t)tftpBytesLength; +- (size_t)tftpGetBytes:(char*)p maxLength:(size_t)ml; + +@end +@implementation NSDictionary (TFTPOptions) + +- (size_t)tftpBytesLength { + __block size_t rv = 0; + [self enumerateKeysAndObjectsUsingBlock:^(id k,id v,BOOL *s) { + rv += [k lengthOfBytesUsingEncoding:NSUTF8StringEncoding]+[v lengthOfBytesUsingEncoding:NSUTF8StringEncoding]+2; + }]; + return rv; +} + +- (size_t)tftpGetBytes:(char*)p maxLength:(size_t)ml { + __block char *_p = p; + __block size_t rl = ml; + __block size_t rv = 0; + [self enumerateKeysAndObjectsUsingBlock:^(NSString *k,NSString *v,BOOL *s) { + NSUInteger l; + [k getBytes:_p maxLength:rl usedLength:&l encoding:NSUTF8StringEncoding options:0 range:NSMakeRange(0,k.length) remainingRange:NULL]; + _p+=l; *_p++=0; rl-=l+1; rv+=l+1; + [v getBytes:_p maxLength:rl usedLength:&l encoding:NSUTF8StringEncoding options:0 range:NSMakeRange(0,v.length) remainingRange:NULL]; + _p+=l; *_p++=0; rl-=l+1; rv+=l+1; + }]; + return rv; +} + +@end + +@implementation TFTPPacket +@synthesize data; + +-(BOOL) isRQOp { + return self.op==tftpOpRRQ || self.op==tftpOpWRQ; +} +-(BOOL) isOptionsOp { + return self.isRQOp || self.op==tftpOpOACK; +} +-(BOOL) isBlockOp { + return self.op==tftpOpDATA || self.op==tftpOpACK; +} + +-(enum TFTPOp)op { + NSAssert(data.length,@"no data"); + return (enum TFTPOp)ntohs(packet->op); +} +-(NSString*)rqFilename { + NSAssert( self.isRQOp, @"Wrong TFTP opcode for rq filename retrieval"); + if(!memchr(packet->rq.data, 0, [data length]-sizeof(packet->op))) return nil; + return @(packet->rq.data); +} +-(NSString*)rqType { + NSAssert( self.isRQOp, @"Wrong TFTP opcode for rq type retrieval"); + const char *z = (const char*)memchr(packet->rq.data,0, data.length-sizeof(packet->op)); + if(!z) return nil; + if(!memchr(z+1,0,data.length-sizeof(packet->op)-(z-packet->rq.data))) return nil; + return @(z+1); +} +-(NSDictionary*)rqOptions { + enum TFTPOp op = self.op; + NSAssert( self.isOptionsOp, @"Wrong TFTP opcode for options retrieval"); + const char *p = packet->any.data, *p1 = (const char*)packet + data.length; + if(op==tftpOpRRQ || op==tftpOpWRQ) { + p = (const char *)memchr(p,0,p1-p); + if(!p) return nil; + p = (const char *)memchr(p+1,0,p1-p); + if(!p) return nil; + ++p; + } + NSMutableDictionary *rv = [NSMutableDictionary dictionaryWithCapacity:8]; + while(p<p1) { + const char *on = p; + p = (const char *)memchr(p,0,p1-p); + if(!p) break; + const char *ov = ++p; + p = (const char *)memchr(p,0,p1-p); + if(!p) break; + ++p; + rv[[@(on) lowercaseString]] = @(ov); + } + return rv; +} +-(uint16_t)block { + NSAssert( self.isBlockOp, @"Wrong TFTP opcode for block number retrieval"); + return ntohs(*(uint16_t*)&packet->data); +} +-(NSData*)rqData { + NSAssert( self.op==tftpOpDATA, @"Can't get data from the request that doesn't have it"); + return [NSData dataWithBytes:packet->data.data length:data.length-sizeof(packet->op)-sizeof(packet->data.block)]; +} +-(uint16_t)rqCode { + NSAssert(self.op==tftpOpERROR,@"Wrong TFTP opcode for error code retrieval"); + return ntohs(packet->err.code); +} +-(NSString*)rqMessage { + NSAssert(self.op==tftpOpERROR,@"Wrong TFTP opcode for error message retrieval"); + return @(packet->err.data); +} + +-(TFTPPacket*)initWithData:(NSData *)d { + if(!(self = [super init])) return self; + packet = (struct AnyTFTPPacket*)(data = [d retain]).bytes; + return self; +} + + ++(TFTPPacket*)packetWithData:(NSData*)d { + return [[[self alloc] initWithData:d] autorelease]; +} ++(TFTPPacket*)packetWithBytesNoCopy:(void*)b andLength:(size_t)l { + return [[[self alloc] initWithData:[NSData dataWithBytesNoCopy:b length:l]] autorelease]; +} + ++(TFTPPacket*)packetErrorWithCode:(enum TFTPError)c andMessage:(NSString*)m { + NSUInteger ml = [m lengthOfBytesUsingEncoding:NSUTF8StringEncoding], bb; + struct AnyTFTPPacket *b = (struct AnyTFTPPacket*)malloc(bb = sizeof(b->op)+sizeof(b->err.code)+ml+1); + if(!b) return nil; + b->op = htons(tftpOpERROR); + b->err.code = ntohs(c); + [m getBytes:b->err.data maxLength:ml usedLength:NULL encoding:NSUTF8StringEncoding options:0 range:NSMakeRange(0,m.length) remainingRange:NULL]; + b->err.data[ml]=0; + return [self packetWithBytesNoCopy:b andLength:bb]; +} ++(TFTPPacket*)packetErrorWithErrno:(int)en andFallback:(NSString *)fb{ + switch(en) { + case EACCES: + return [self packetErrorWithCode:tftpErrAccessViolation andMessage:@"acess violation"]; + case ENOENT: + return [self packetErrorWithCode:tftpErrNotFound andMessage:@"not found"]; + } + return [self packetErrorWithCode:tftpErrUndefined andMessage:fb]; +} + ++(TFTPPacket*)packetXRQWithOp:(enum TFTPOp)op file:(NSString*)f xferType:(NSString*)t andOptions:(NSDictionary*)o { + NSAssert(f && t && o,@"Something is amiss in packetXRQWithOp"); + __block size_t dl = o.tftpBytesLength + +[f lengthOfBytesUsingEncoding:NSUTF8StringEncoding] + +[t lengthOfBytesUsingEncoding:NSUTF8StringEncoding] + +2; + size_t pl = dl; + struct AnyTFTPPacket *b = (struct AnyTFTPPacket*)malloc(pl+=sizeof(b->op)); + if(!b) return nil; + b->op = htons(op); + __block char *p = b->rrq.data; + NSUInteger l; + [f getBytes:p maxLength:dl usedLength:&l encoding:NSUTF8StringEncoding options:0 range:NSMakeRange(0,f.length) remainingRange:NULL]; + p+=l; *p++=0; dl-=l+1; + [t getBytes:p maxLength:dl usedLength:&l encoding:NSUTF8StringEncoding options:0 range:NSMakeRange(0,t.length) remainingRange:NULL]; + p+=l; *p++=0; dl-=l+1; + l = [o tftpGetBytes:p maxLength:dl]; + p+=l; dl-=l; + NSAssert1(dl==0,@"packet of the wrong size, remaining count: %lu",dl); + return [self packetWithBytesNoCopy:b andLength:pl]; +} + ++(TFTPPacket*)packetRRQWithFile:(NSString *)f xferType:(NSString *)t andOptions:(NSDictionary *)o { + return [self packetXRQWithOp:tftpOpRRQ file:f xferType:t andOptions:o]; +} ++(TFTPPacket*)packetWRQWithFile:(NSString *)f xferType:(NSString *)t andOptions:(NSDictionary *)o { + return [self packetXRQWithOp:tftpOpWRQ file:f xferType:t andOptions:o]; +} + ++(TFTPPacket*)packetOACKWithOptions:(NSDictionary*)o { + __block NSUInteger pl = [o tftpBytesLength]; + __block NSUInteger rc = pl; + __block struct AnyTFTPPacket *b = (struct AnyTFTPPacket*)malloc(pl+=sizeof(b->op)); + if(!b) return nil; + b->op = htons(tftpOpOACK); + __block char *p = b->oack.data; + rc -= [o tftpGetBytes:p maxLength:pl]; + NSAssert1(rc==0,@"packet of the wrong size, remaining count: %lu",rc); + return [self packetWithBytesNoCopy:b andLength:pl]; +} ++(TFTPPacket*)packetDataWithBlock:(uint16_t)b andData:(NSData*)d { + NSUInteger pl; + struct AnyTFTPPacket *p = (struct AnyTFTPPacket*)malloc(pl=sizeof(p->op)+sizeof(p->data.block)+d.length); + if(!p) return nil; + p->op = htons(tftpOpDATA); + p->data.block = htons(b); + [d getBytes:p->data.data length:d.length]; + return [self packetWithBytesNoCopy:p andLength:pl]; +} ++(TFTPPacket*)packetACKWithBlock:(uint16_t)b { + NSUInteger pl; + struct AnyTFTPPacket *p = (struct AnyTFTPPacket*)malloc(pl=sizeof(p->op)+sizeof(p->ack.block)); + if(!p) return nil; + p->op = htons(tftpOpACK); + p->ack.block = htons(b); + return [self packetWithBytesNoCopy:p andLength:pl]; +} + +-(void)dealloc { + [data release]; + [super dealloc]; +} + +@end |