diff options
Diffstat (limited to 'common.h')
| -rw-r--r-- | common.h | 132 |
1 files changed, 131 insertions, 1 deletions
@@ -1,5 +1,9 @@ +#include <stdarg.h> #include <stdint.h> #include <stdio.h> +#include <string.h> +#include <sys/socket.h> +#include <unistd.h> #define PORT 9983 // max buffer size sent over network @@ -23,7 +27,7 @@ typedef uint32_t u32; struct message { char author[MESSAGE_AUTHOR_LEN]; char timestamp[MESSAGE_TIMESTAMP_LEN]; // HH:MM:SS - u16 len; + u16 len; // length of the text including null terminator char *text; }; @@ -47,3 +51,129 @@ u32 send_message(struct message msg, u32 serverfd); // if recv() returns 0 or -1 it will return early and return 0 or -1 accordingly. // Otherwise returns the number of bytes received u32 receive_message(struct message *msg, u32 clientfd); + +void writef(char *format, ...) +{ + char buf[255 + 1]; + va_list args; + va_start(args, format); + + vsnprintf(buf, sizeof(buf), format, args); + va_end(args); + + int n = 0; + while (*(buf + n) != 0) + n++; + write(0, buf, n); +} + +// Returns the length of the string plus the null terminator +u16 str_len(char *str) +{ + if (*str == 0) + return 0; + + u16 i = 0; + while (str[i]) + i++; + + return i + 1; +} + +void str_cpy(char *to, char *from) +{ + while ((*to++ = *from++)) + ; +} + +// Save msg to file f +// Returns 0 on success, returns 1 if msg->text is NULL, returns 2 if mfg->len is 0 +u8 save_message(struct message *msg, FILE *f) +{ + if (msg->text == NULL) { + return 1; + } else if (msg->len == 0) + return 2; + + fwrite(&msg->timestamp, sizeof(*msg->timestamp) * MESSAGE_TIMESTAMP_LEN, 1, f); + fwrite(&msg->author, sizeof(*msg->author) * MESSAGE_AUTHOR_LEN, 1, f); + fwrite(&msg->len, sizeof(msg->len), 1, f); + fputs(msg->text, f); + + return 0; +} + +u8 load_message(struct message *msg, FILE *f) +{ + fread(msg, sizeof(*msg->timestamp) * MESSAGE_TIMESTAMP_LEN + sizeof(*msg->author) * MESSAGE_AUTHOR_LEN, 1, f); + u16 len; + fread(&len, sizeof(len), 1, f); + if (len == 0) { + // TODO: Error: empty message should not be allowed + // empty message + msg->text = ""; + return 1; + } + char txt[len]; + fgets(txt, len, f); + msg->text = txt; + + return 0; +} + +u32 send_message(struct message msg, u32 serverfd) +{ + // stream length : message author : message timestamp : message text + \0 + u32 buf_len = sizeof(buf_len) + MESSAGE_AUTHOR_LEN + MESSAGE_TIMESTAMP_LEN + msg.len; + char buf[buf_len]; + u32 offset; + + memcpy(buf, &buf_len, sizeof(buf_len)); + offset = sizeof(buf_len); + memcpy(buf + offset, msg.author, MESSAGE_AUTHOR_LEN); + offset += MESSAGE_AUTHOR_LEN; + memcpy(buf + offset, msg.timestamp, MESSAGE_TIMESTAMP_LEN); + offset += MESSAGE_TIMESTAMP_LEN; + memcpy(buf + offset, msg.text, msg.len); + + u32 n = send(serverfd, &buf, buf_len, 0); + if (n == -1) + return n; + + writef("%d bytes sent.\n", n); + return n; +} + +u32 receive_message(struct message *msg, u32 clientfd) +{ + // must all be of the s + u32 nrecv, buf_len; + // limit on what can be received with recv() + u32 buf_size = 20; + // temporary buffer to receive message data over a stream + char recv_buf[BUF_MAX]; + + nrecv = recv(clientfd, recv_buf, buf_size, 0); + if (nrecv == 0 || nrecv == -1) + return nrecv; + + memcpy(&buf_len, recv_buf, sizeof(buf_len)); + + u32 i = 0; + while (nrecv < buf_len) { + // advance the copying by the amounts of bytes received each time + i = recv(clientfd, recv_buf + nrecv, buf_size, 0); + if (i == 0 || i == -1) + return nrecv; + nrecv += i; + } + + struct message received = {0}; + memcpy(&received, recv_buf + sizeof(buf_len), MESSAGE_AUTHOR_LEN + MESSAGE_TIMESTAMP_LEN); + received.text = recv_buf + sizeof(buf_len) + MESSAGE_AUTHOR_LEN + MESSAGE_TIMESTAMP_LEN; + received.len = buf_len - sizeof(buf_len) - MESSAGE_AUTHOR_LEN - MESSAGE_TIMESTAMP_LEN; + + // assume clientfd is serverfd + 1; + writef("Received %d bytes from client(%d): %s [%s] (%d)%s\n", nrecv, clientfd - 3, received.timestamp, received.author, received.len, received.text); + return nrecv; +} |