diff options
Diffstat (limited to 'listener.c')
| -rw-r--r-- | listener.c | 42 |
1 files changed, 29 insertions, 13 deletions
@@ -13,9 +13,7 @@ #include <arpa/inet.h> #include <netdb.h> -#define MYPORT "4950" // the port users will be connecting to - -#define MAXBUFLEN 100 +#include "common.h" // get sockaddr, IPv4 or IPv6: void *get_in_addr(struct sockaddr *sa) @@ -27,7 +25,7 @@ void *get_in_addr(struct sockaddr *sa) return &(((struct sockaddr_in6*)sa)->sin6_addr); } -int main(void) +int main(int argc, char *argv[], char *envp[]) { int sockfd; struct addrinfo hints, *servinfo, *p; @@ -43,7 +41,7 @@ int main(void) hints.ai_socktype = SOCK_DGRAM; hints.ai_flags = AI_PASSIVE; // use my IP - if ((rv = getaddrinfo(NULL, MYPORT, &hints, &servinfo)) != 0) { + if ((rv = getaddrinfo(NULL, SERVERPORT_S, &hints, &servinfo)) != 0) { fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv)); return 1; } @@ -74,16 +72,34 @@ int main(void) addr_len = sizeof their_addr; - if ((numbytes = recvfrom(sockfd, buf, MAXBUFLEN-1 , 0, - (struct sockaddr *)&their_addr, &addr_len)) == -1) { - perror("recvfrom"); - exit(1); + while ((numbytes = recvfrom(sockfd, buf, MAXBUFLEN-1 , 0, + (struct sockaddr *)&their_addr, &addr_len)) != -1) { + // decode packet & launch handler + buf[numbytes] = '\0'; + char *task = buf, + *cl_argv[3] = {buf, (strlen(task)<numbytes) ? (buf+strlen(task)+1) : NULL, NULL }; + + if (buf[0] == '/' || strstr(buf, "..")) { + fprintf(stderr, "payload tried directory traversal\n"); + continue; + } + + switch (fork()) { + case 0: + // TODO: clean file descriptors + execve(task, cl_argv, envp); + perror("exec"); + exit(-1); + case -1: + perror("fork (serious!)"); + exit(-1); + default: + wait(); + } } - buf[numbytes] = '\0'; - printf("%s\n", buf); - + perror("recvfrom"); close(sockfd); - return 0; + return -1; } |